Enhancing Plant Biodiversity, Soil Health and Agroecosystem Resilience: The Role of Cereal-Legume Crop Rotations

Abstract

Agroecosystems must maintain high productivity over time and contribute to restoring the biodiversity and functionality of soils while agroecosystems yield the food we eat; however, the diversity related to food and agriculture has been shrinking. With this systematic review, the narrative and evidence map synthesized existing evidence about how cereal-legume rotations (as a form of diversifying crop diversity) could improve the diversity and function of the plant and functional aspects of biodiversity while restoring the soil health and agroecosystem resilience. A PRISMA 2020 report has been created alongside this work. This evidence will be used to understand improvements in soil physical and biological traits, nutrient cycles, and biologically fixed N, regulated pests/diseases/weeds, productivity and yield stability, environmental efficiency, and outcomes. In addition, several pieces of evidence were included and explained concerning the N cycle in cereal-legume rotations. When used compared to monoculture cereal systems, cereal-legume rotations lead to improved soil structure, activity, and nutritional status (N fixing) and may decrease pests and disease; these conditions often promote a better harvest or lead to higher and/or more stable productivity. Crop residue-based SOC increases are generally moderate in duration and degree. The increase in microbial biomass occurred more quickly over the years. For the environment, cereal-legume rotations generally achieve a lower total environmental efficiency due to lower N fertilizer inputs (N fixing), which means a lower C footprint per ton of production of crops, yet this strategy can also cause some environmental consequences, such as increasing N₂O emissions (due to over N fixing), which cause global warming and nitrate leaching when N is fixed in excess, not coupled with crop requirements, creating pollution. The rotation is context-dependent, so each site-specific system needs to be analyzed to improve trade-offs to yield, productivity, and environmental conservation.

1. Introduction

Agricultural production is increasingly expected to deliver multiple outcomes simultaneously, including stable yields and farm income, efficient use of inputs, climate mitigation/adaptation, and measurable gains for biodiversity and soil functioning [1]. However, global assessments consistently show that biodiversity associated with food and agriculture is declining, while key ecosystem services underpinning production (e.g., soil formation, nutrient cycling, biological regulation) are being degraded due to land-use change, agricultural intensification, and the simplification of cropping systems [2,3,4,5].

Within this context, plant biodiversity has emerged as a fundamental component of agroecosystems. Beyond species richness, functional diversity plays a critical role in regulating ecosystem processes, including nutrient cycling, soil biological activity, and resistance to biotic and abiotic stress [6,7,8]. In agroecosystems, biodiversity supports regulation processes such as pollination, biological pest control, and soil fertility maintenance, all of which are necessary for sustainable systems [9,10].

A practical and scalable strategy to restore biodiversity and ecosystem functioning is crop diversification, particularly through temporal diversification via crop rotation [1,11].Cereal-legume rotations represent one of the most effective and widely applicable diversification strategies, as they directly address key agroecosystem challenges by enhancing soil fertility through biological nitrogen fixation, improving soil structure and microbial activity, and increasing biodiversity at both above- and below-ground levels [12,13].

While other diversification strategies, such as intercropping and cover cropping, also contribute to improved ecosystem functioning, they differ in their mechanisms and practical applicability. Intercropping systems can enhance resource-use efficiency and biodiversity through spatial complementarity. However, they often involve increased management complexity and require careful species selection, which may limit their adoption in large-scale, mechanized systems [14,15]. Similarly, cover crops provide important benefits such as soil protection, erosion control, and short-term nutrient retention, but their effects are typically indirect and may not always translate into immediate productivity gains for the main crops [16,17]. In contrast, cereal-legume rotations offer a temporally structured and more easily implementable form of diversification that integrates seamlessly into conventional farming systems, delivering cumulative benefits for soil fertility, nutrient cycling, and crop productivity over time. This makes them a particularly suitable strategy for achieving both sustainability and scalability in modern agriculture [12].

Beyond agronomic tradition, crop rotations are now supported by a large empirical base showing that diversified cropping systems tend to enhance above- and below-ground biodiversity and multiple ecosystem services, often without penalizing yields [1,18]. Likewise, a global synthesis indicates that biodiversity (including richness of pollinators and natural enemies) can directly support intermediate services such as pollination and biological control, translating to crop-production benefits under real-world conditions [8].

Among diversification options, cereal-legume rotations occupy a central position because they combine the productivity and market role of cereals with the ecological functions of legumes. Legumes contribute biologically fixed nitrogen and can reduce reliance on synthetic N inputs, while also influencing residue quality, rhizosphere processes, soil structure, and the soil microbiome—pathways that collectively affect soil health and system stability. Over longer time scales, evidence from long-term experiments indicates that increasing rotational diversity can enhance cereal yields and that benefits can strengthen with time, consistent with cumulative improvements in soil and biological regulation [19].

However, crop diversification should be considered at different levels of biodiversity. Diversity of species and functions in rotations interplay with within-crop genetic diversity (e.g., cultivar mixtures), landscape complexity (field margins, semi-natural habitats), and the wider pool of genetic resources available for adaptation. Food security concerns related to global food-supply homogenization [20] and documented shortfalls in the conservation of CWRs [21] emphasize the need for integrative approaches that connect rotation design with broader agrobiodiversity objectives, particularly as climate variability intensifies and new pests and pathogens emerge.

Despite the extensive body of literature on cereal-legume rotations, existing studies often focus on individual components such as nitrogen fixation, soil properties, or crop productivity, with comparatively fewer efforts to integrate these aspects within a comprehensive agroecosystem framework. In particular, limited attention has been given to the simultaneous evaluation of plant biodiversity, soil biological functioning, agroecosystem resilience, and environmental trade-offs across different contexts. Moreover, while the benefits of legume inclusion are widely recognized, uncertainties remain regarding their variability under different management practices and environmental conditions, as well as potential trade-offs such as increased N₂O emissions and nitrate leaching. Therefore, there is a clear need for a holistic synthesis that not only consolidates current knowledge but also explicitly addresses these interactions and context dependencies. This review aims to fill this gap by integrating evidence across multiple analytical domains and providing a comprehensive assessment of cereal-legume rotations as a strategy for sustainable intensification.

In this paper, we review evidence that cereal-legume rotational cropping (CLC) systems contribute to plant and functional agrobiodiversity, soil health factors such as physical fertility (structure, fertility), nutrient cycling, and biological activity supportintegrated pest/disease/weed regulation, strengthening agroecosystem resilience while taking into account productivity and environmental trade-offs. We also share design principles for adopting cereal-legume rotations in diverse agroecological settings, ranging from choosing legume functional types and cultivars to combining these rotations with soil-conservation practices, broader biodiversity-based management (e.g., integrating underutilized species, genetic diversification, or landscape elements that support beneficial biota). Finally, we highlight remaining challenges and research needs to develop cereal-legume rotations as a foundational practice in sustainable, resilient cropping systems. To synthesize the relationship between crop diversification, soil processes, ecosystem services, and agroecosystem performance, a conceptual framework is presented in Figure 1.

2. Materials and Methods

2.1. Review Design and Conceptual Framework

Review Design and PRISMA Reporting Framework

This study is presented as a systematic review with narrative synthesis and systematic evidence mapping. The aim was not to perform a quantitative meta-analysis, but to provide a transparent and reproducible synthesis of evidence on cereal-legume crop rotations and their effects on plant biodiversity, soil health, agroecosystem resilience, productivity, environmental performance, and economic sustainability. The review followed the PRISMA 2020 reporting framework for study identification, screening, eligibility assessment, and reporting of the selection process [22]. The completed PRISMA 2020 checklist is provided as Supplementary Table S1. The review was not registered in PROSPERO or another registry, and no review protocol was published before the review was conducted.

The conceptual framework was based on biodiversity-ecosystem functioning theory [23] and principles of agroecological intensification [1,24]. The synthesis linked six analytical dimensions: (i) plant and functional agrobiodiversity, (ii) soil physical, chemical and biological indicators, (iii) pest, disease and weed regulation, (iv) crop productivity and yield stability, (v) environmental impacts, including greenhouse gas emissions, carbon footprint, and nutrient losses, and (vi) economic sustainability and adoption drivers.

2.2. Literature Search Strategy and Information Sources

A structured literature search was conducted in Scopus and Google Scholar to identify peer-reviewed studies published between 2000 and 2025. Foundational earlier studies were also considered when they were conceptually important for biodiversity-ecosystem functioning theory, agroecology, crop rotation theory, or soil biological processes. The final search was completed on 15 February 2026. The search strategy combined three conceptual blocks: (i) cereal-legume rotations and crop diversification; (ii) soil health, biological nitrogen fixation, biodiversity, productivity, and resilience; and (iii) environmental and economic outcomes. Boolean operators, truncation, and phrase searching were used where supported by each database. In Scopus, searches were conducted in title, abstract, and keywords. In Google Scholar, equivalent phrase-based searches were used, and results were screened sequentially according to relevance.

The main Scopus search string was: TITLE-ABS-KEY ((“cereal-legume rotation*” OR “cereal legume rotation*” OR “legume-based rotation*” OR “grain legume*” OR “pulse crop*” OR “crop rotation*” OR “crop diversification”) AND (“soil health” OR “soil organic carbon” OR “soil aggregation” OR “microbial biomass” OR “microbial diversity” OR “biological nitrogen fixation” OR “nitrogen fixation” OR “N credit*” OR “yield stability” OR “agroecosystem resilience” OR “pest*” OR “disease*” OR “weed*” OR “greenhouse gas*” OR “nitrous oxide” OR “N₂O” OR “carbon footprint” OR “life cycle assessment” OR “agrobiodiversity”)) AND PUBYEAR > 1999 AND PUBYEAR < 2026.

Additional targeted Scopus strings were used for specific domains: (i) (“cereal-legume rotation*” OR “legume-based rotation*” OR “grain legume*”) AND (“biological nitrogen fixation” OR “N credit*” OR “nitrogen cycling” OR “fertilizer reduction”); (ii) (“crop rotation*” OR “cereal-legume rotation*” OR “legume-based rotation*”) AND (“soil organic carbon” OR “soil microbial biomass” OR “soil enzyme activity” OR “soil aggregation” OR “soil health”); (iii) (“crop rotation*” OR “cereal-legume rotation*” OR “crop diversification”) AND (“integrated pest management” OR “weed seedbank” OR “disease suppression” OR “pest regulation”); and (iv) (“legume rotation*” OR “pulse crop*” OR “cereal-legume rotation*”) AND (“N₂O” OR “nitrous oxide” OR “carbon footprint” OR “greenhouse gas emissions” OR “life cycle assessment” OR “nitrate leaching”). Equivalent Google Scholar phrases included “cereal legume rotation soil health”, “legume-based rotation biological nitrogen fixation N credit”, “grain legumes cereal rotation yield stability”, “crop diversification agroecosystem resilience soil microbial biomass”, “cereal legume rotation pest disease weed management”, and “legume rotation nitrous oxide carbon footprint life cycle assessment”.

Search outputs were recorded and screened for relevance. Duplicate records were removed using title, author names, publication year, journal name, and DOI, where available. Records were first screened by title and abstract, followed by full-text eligibility assessment. Eligibility decisions were made by the author team using the predefined criteria below; uncertain cases were resolved by consensus. No automation tools were used for screening or exclusion decisions.

The search identified 111 records through database searches (Google Scholar, n = 72; Scopus, n = 39). Before screening, 10 duplicate records and 11 non-article records (e.g., PowerPoint presentations, posters, and other non-peer-reviewed formats) were removed, leaving 90 records for title and abstract screening. Nine records were excluded at title/abstract screening because they were not related to the research aim. Eighty-one reports were sought and retrieved for full-text eligibility assessment. Five reports were excluded after full-text assessment because they were not related to the research aim or did not provide evidence relevant to the review domains. A total of 76 studies were included in the final synthesis. The study selection process is shown in Figure 2.

2.3. Inclusion and Exclusion Criteria

Studies were included when they: (i) examined cereal-legume rotations, grain-legume pre-crop effects, pulse-based rotations or legume-based diversification in arable systems; (ii) reported quantitative or qualitative effects on at least one of the following domains: soil physical, chemical or biological properties; biological nitrogen fixation or N credits; pest, disease or weed dynamics; crop yield or yield stability; greenhouse gas emissions or carbon footprint; nutrient losses; or economic performance; and (iii) were based on field experiments, long-term trials, meta-analyses, systematic or structured reviews, life cycle assessments or robust case studies with sufficient methodological transparency.

Studies were excluded when they focused exclusively on intercropping without rotation relevance, addressed horticultural systems outside the field-crop focus, lacked methodological transparency, or were non-peer-reviewed opinion papers without empirical or synthesis-based evidence. General biodiversity, policy, and methodological sources were used only for contextual or methodological framing and were not counted among the 76 included studies. The 76 studies included in the evidence synthesis are listed in Appendix A (

Table A1. Characteristics of the 76 evidence records included in the systematic evidence synthesis.

Evidence Record No. (Bibliography Ref.)	Study	Evidence Type/Domain	Main Relevance to Synthesis
1 ([1])	Tamburini, G (2020). Agricultural diversification promotes multiple ecosystem services without compromising yield	Peer-reviewed study; Productivity/economic performance	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
2 ([5])	Beillouin, D (2019). Evidence map of crop diversification strategies at the global scale	Meta-analysis/evidence synthesis; Agrobiodiversity/resilience	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
3 ([7])	Tscharntke, T (2005). Landscape perspectives on agricultural intensification and biodiversity–ecosystem service management	Peer-reviewed study; Agrobiodiversity/resilience	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
4 ([8])	Dainese, M (2019). A global synthesis reveals biodiversity-mediated benefits for crop production	Meta-analysis/evidence synthesis; Agrobiodiversity/resilience	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
5 ([10])	Balzan, M (2020). Assessing Ecosystem Services Supplied by Agroecosystems in Mediterranean Europe: A Literature Review	Review/synthesis; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
6 ([11])	Schiller, J (2024). Higher crop rotational diversity in more simplified agricultural landscapes in Northeastern Germany	Peer-reviewed study; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
7 ([12])	Zhang, L (2025). Legume-based rotation benefits crop productivity and agricultural sustainability in the North China Plain	Field experiment/empirical study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
8 ([13])	Malik, A (2025). Exploring the plant and soil mechanisms by which crop rotations benefit farming systems	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
9 ([14])	Liu, K (2020). Intensifying crop rotations with pulse crops enhances system productivity and soil organic carbon in semi-arid environments	Field experiment/empirical study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
10 ([15])	Brooker, R (2015). Improving intercropping: a synthesis of research in agronomy, plant physiology and ecology	Review/synthesis; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
11 ([16])	Blanco-Canqui, H (2015). Cover crops and ecosystem services: Insights from studies in temperate soils	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
12 ([17])	Poeplau, C (2015). Carbon sequestration in agricultural soils via cultivation of cover crops–A meta-analysis	Meta-analysis/evidence synthesis; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
13 ([18])	Letourneau, D (2011). Does plant diversity benefit agroecosystems? A synthetic review	Review/synthesis; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
14 ([19])	Smith, M (2023). Increasing crop rotational diversity can enhance cereal yields	Peer-reviewed study; Productivity/economic performance	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
15 ([26])	Al-Musawi, Z (2025). Utilizing Different Crop Rotation Systems for Agricultural and Environmental Sustainability: A Review	Review/synthesis; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
16 ([27])	Shah, K (2021). Diversified Crop Rotation: An Approach for Sustainable Agriculture Production	Peer-reviewed study; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
17 ([28])	Liu, C (2022). Chapter Six—Diversifying crop rotations enhances agroecosystem services and resilience	Review/synthesis; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
18 ([29])	Zhao, J (2020). Does crop rotation yield more in China? A meta-analysis	Meta-analysis/evidence synthesis; Productivity/economic performance	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
19 ([30])	Chan, K (1996). The influence of crop rotation on soil structure and soil physical properties under conventional tillage	Field experiment/empirical study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
20 ([31])	Quddus Md, A (2017). Crop yields, nutrient uptake and apparent balances for lentil-mungbean-T	LCA study/review; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
21 ([32])	King, A (2018). Crop rotations for increased soil carbon: perenniality as a guiding principle	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
22 ([33])	Canarini, A (2018). Mineral-Associated Soil Carbon is Resistant to Drought but Sensitive to Legumes and Microbial Biomass in an Australian Grassland	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
23([34])	Lepetit, M (2023). Control of the rhizobium–legume symbiosis by the plant nitrogen demand is tightly integrated at the whole plant level and requires inter-organ systemic signaling	Field experiment/empirical study; Nitrogen dynamics/BNF	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
24 ([35])	Guo, K (2023). Biological nitrogen fixation in cereal crops: Progress, strategies, and perspectives	Peer-reviewed study; Nitrogen dynamics/BNF	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
25 ([36])	Preissel, S (2015). Magnitude and farm-economic value of grain legume pre-crop benefits in Europe: A review	Review/synthesis; Productivity/economic performance	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
26 ([37])	Ghosh, P (2020). Grain legume inclusion in cereal–cereal rotation increased base crop productivity in the long run	Field experiment/empirical study; Productivity/economic performance	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
27 ([38])	Han, E (2021). Can precrops uplift subsoil nutrients to topsoil?	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
28 ([39])	Zou, Y (2024). Crop Rotation and Diversification in China: Enhancing Sustainable Agriculture and Resilience	Peer-reviewed study; Agrobiodiversity/resilience	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
29 ([40])	Liu, C (2023). Legume-based rotation enhances subsequent wheat yield and maintains soil carbon storage	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
30 ([43])	Siczek, A (2020). Variation in soil microbial population and enzyme activities under faba bean as affected by pentachlorophenol	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
31 ([44])	Borase, D (2020). Long-term impact of diversified crop rotations and nutrient management practices on soil microbial functions and soil enzymes activity	Field experiment/empirical study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
32 ([45])	Nath, C (2021). Impact of variable tillagebased residue management and legumebased cropping for seven years on enzymes activity, soil quality index and crop productivity in rice ecology	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
33 ([46])	Liu, M (2024). Effects of leguminous green manure–crop rotation on soil enzyme activity and stoichiometry	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
34 ([47])	Kerdraon, L (2019). Microbiomes and Pathogen Survival in Crop Residues, an Ecotone Between Plant and Soil	Peer-reviewed study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
35 ([48])	Lin, B (2011). Resilience in Agriculture through Crop Diversification: Adaptive Management for Environmental Change	Peer-reviewed study; Agrobiodiversity/resilience	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
36 ([49])	Ratnadass, A (2012). Plant species diversity for sustainable management of crop pests and diseases in agroecosystems: a review	Review/synthesis; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
37 ([50])	van Bruggen, A (2016). Plant disease management in organic farming systems	Peer-reviewed study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
38 ([51])	Liebman, M (1993). Crop Rotation and Intercropping Strategies for Weed Management	Peer-reviewed study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
39 ([52])	Schwartz-Lazaro, L (2019). A Review of the Soil Seedbank from a Weed Scientists Perspective	Review/synthesis; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
40 ([53])	Saulic, M (2022). How Do Long Term Crop Rotations Influence Weed Populations: Exploring the Impacts of More than 50 Years of Crop Management in Serbia	Peer-reviewed study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
41 ([54])	Sharma, G (2021). Crop Diversification for Improved Weed Management: A Review	Review/synthesis; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
42 ([55])	Davis, A (2012). Increasing cropping system diversity balances productivity, profitability and environmental health	Peer-reviewed study; Productivity/economic performance	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
43 ([56])	Adeux, G (2019). Diversified grain-based cropping systems provide long-term weed control while limiting herbicide use and yield losses	Field experiment/empirical study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
44 ([57])	Pedersen, E (1992). The effect of crop rotation on development of the septoria disease complex on spring wheat in Saskatchewan	Field experiment/empirical study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
45 ([58])	Kutcher, H (2013). Blackleg disease of canola mitigated by resistant cultivars and four-year crop rotations in western Canada	Field experiment/empirical study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
46 ([59])	Liu, Q (2023). Changes in soil microbial biomass, diversity, and activity with crop rotation in cropping systems: A global synthesis	Meta-analysis/evidence synthesis; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
47 ([60])	Peng, G (2015). A >2-year crop rotation reduces resting spores of Plasmodiophora brassicae in soil and the impact of clubroot on canola	Peer-reviewed study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
48 ([61])	Harker, K (2016). Diverse Rotations and Optimal Cultural Practices Control WildOat (Avena fatua)	Peer-reviewed study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
49 ([62])	Beckie, H (2014). Selection and evolution of acetyl-CoA carboxylase (ACC)-inhibitor resistance in wild oat (Avena fatua L.) in a long-term alternative cropping systems study	Field experiment/empirical study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
50 ([63])	Munir, S (2019). Crop diversity and pest management in sustainable agriculture	Peer-reviewed study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
51 ([64])	Jalli, M (2021). Effects of Crop Rotation on Spring Wheat Yield and Pest Occurrence in Different Tillage Systems: A Multi-Year Experiment in Finnish Growing Conditions	Field experiment/empirical study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
52 ([65])	Smith, C (2020). Grain legumes in crop rotations under low and variable rainfall: are observed short-term N benefits sustainable?	Peer-reviewed study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
53 ([67])	Gaudin, A (2015). Increasing crop diversity mitigates weather variations and improves yield stability	Peer-reviewed study; Productivity/economic performance	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
54 ([68])	Schwenke, G (2015). Soil N2O emissions under N2-fixing legumes and N-fertilised canola: a reappraisal of emissions factor calculations	Peer-reviewed study; Environmental performance/GHG-LCA	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
55 ([69])	Lemke, R (2018). Effect of crop and residue type on nitrous oxide emissions from rotations in the semi-arid Canadian prairies	Field experiment/empirical study; Environmental performance/GHG-LCA	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
56 ([70])	Biernat, L (2020). Nitrous oxide emissions and methane uptake from organic and conventionally managed arable crop rotations on farms in Northwest Germany	Peer-reviewed study; Environmental performance/GHG-LCA	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
57 ([71])	Li, G (2021). Can legume species, crop residue management or no-till mitigate nitrous oxide emissions from a legume-wheat crop rotation in a semi-arid environment?	Field experiment/empirical study; Environmental performance/GHG-LCA	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
58 ([72])	Matthews, L (2025). Legumes and livestock in no-till crop rotations: Effects on nitrous oxide emissions, carbon sequestration, yield, and wheat protein content	Peer-reviewed study; Environmental performance/GHG-LCA	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
59 ([73])	Gan, Y (2011). Strategies for reducing the carbon footprint of field crops for semiarid areas	Review/synthesis; Environmental performance/GHG-LCA	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
60 ([74])	Gan, Y (2011). Lowering carbon footprint of durum wheat by diversifying cropping systems	Field experiment/empirical study; Environmental performance/GHG-LCA	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
61 ([75])	Gan, Y (2014). Improving farming practices reduces the carbon footprint of spring wheat production	Peer-reviewed study; Environmental performance/GHG-LCA	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
62 ([76])	Costa, M (2020). Representing crop rotations in life cycle assessment: a review of legume LCA studies	Review/synthesis; Environmental performance/GHG-LCA	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
63 ([77])	Nemecek, T (2008). Environmental impacts of introducing grain legumes into European crop rotations	Peer-reviewed study; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
64 ([78])	De Notaris, C (2023). Faba bean productivity, yield stability and N2-fixation in long-term organic and conventional crop rotations	Field experiment/empirical study; Nitrogen dynamics/BNF	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
65 ([79])	Franke, A (2018). Sustainable intensification through rotations with grain legumes in Sub-Saharan Africa: A review	Review/synthesis; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
66 ([80])	Yigezu, Y (2019). Legume-based rotations have clear economic advantages over cereal monocropping in dry areas	Peer-reviewed study; Productivity/economic performance	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
67 ([81])	Dabessa, A (2023). Long-term soybean–maize rotation experiments in cereal-based farming systems at Bako, Western Ethiopia	Field experiment/empirical study; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
68 ([82])	Zhao, Y (2022). Nitrogen fixation and transfer between legumes and cereals under various cropping regimes	Peer-reviewed study; Nitrogen dynamics/BNF	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
69 ([83])	Chen, S (2022). Crop rotation increases root biomass and promotes the correlation of soil dissolved carbon with the microbial community in the rhizosphere	Field experiment/empirical study; Soil health/biological activity	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
70 ([84])	Molla, A (2022). Effect of Different Tillage Practices on Sunflower (Helianthus annuus) Cultivation in a Crop Rotation System with Intercropping Triticosecale-Pisum sativum	Field experiment/empirical study; Crop diversification evidence	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
71 ([87])	Mundt, C (2002). USE OF MULTILINE CULTIVARS AND CULTIVAR MIXTURES FOR DISEASE MANAGEMENT	Review/synthesis; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
72 ([88])	Zhu, Y (2000). Genetic diversity and disease control in rice	Peer-reviewed study; Biotic regulation	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
73 ([89])	Hajjar, R (2007). The use of wild relatives in crop improvement: a survey of developments over the last 20 years	Peer-reviewed study; Agrobiodiversity/resilience	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
74 ([90])	Warschefsky, E (2014). Back to the wilds: tapping evolutionary adaptations for resilient crops through systematic hybridization with crop wild relatives	Peer-reviewed study; Agrobiodiversity/resilience	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
75 ([91])	Dempewolf, H (2014). Adapting agriculture to climate change: a global initiative to collect, conserve, and use crop wild relatives	Peer-reviewed study; Agrobiodiversity/resilience	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.
76 ([92])	Hunter, D (2019). The potential of neglected and underutilized species for improving diets and nutrition	Peer-reviewed study; Agrobiodiversity/resilience	Included because it addresses cereal-legume rotations, crop diversification, soil health, biodiversity, productivity, environmental performance, pest/disease/weed regulation, or system resilience relevant to the review framework.

) with corresponding reference numbers.

2.4. Data Extraction and Thematic Synthesis

For each included study, the following information was extracted where available: agroecological zone and geographic location; rotation duration and crop species; management practices such as residue management, tillage, fertilization and irrigation; soil indicators, including aggregation, nutrient availability, microbial biomass carbon, microbial biomass nitrogen and soil organic carbon; biological nitrogen fixation or N-credit metrics; pest, disease and weed suppression outcomes; crop yield and yield stability metrics; environmental metrics, including carbon footprint, nitrate leaching and N₂O emissions; and economic metrics such as gross margin and input reduction.

Data were synthesized using thematic grouping rather than quantitative meta-analysis because of substantial heterogeneity among study designs, crop sequences, soil and climatic contexts, management practices, and outcome metrics. Where available, percentage changes, reported effect sizes, and quantitative values from meta-analyses or long-term experiments were highlighted to provide comparative context. Results were tabulated or summarized visually in a series of tables presented below, together with a corresponding table provided in Appendix A (Table A1).

2.5. Study Quality and Risk-of-Bias Assessment

A structured quality and risk-of-bias assessment was conducted to evaluate the reliability of evidence included in the synthesis. Because the review incorporated heterogeneous evidence types, a single risk-of-bias tool was not appropriate for all studies. Therefore, an adapted appraisal framework was applied according to study type, drawing on established principles for critical appraisal and narrative review quality assessment [24,25].

Primary field experiments and long-term trials were assessed using the following criteria: clarity of research objective and rotation treatment description; adequacy of experimental design, including replication, controls, and duration; transparency of management practices such as fertilization, tillage, irrigation, and residue handling; appropriateness and reliability of outcome measurements; and clarity of statistical analysis and reporting. Meta-analyses and review-based syntheses were assessed according to transparency of search strategy, inclusion criteria, data extraction, heterogeneity assessment, and interpretation of effect sizes. Life cycle assessment studies were appraised according to the clarity of functional unit, system boundaries, allocation procedures, representation of crop rotations, treatment of nitrogen fixation, and uncertainty or sensitivity analysis.

Studies were rated as having low, medium, or high concern. Low-concern studies had explicit objectives, transparent methods, appropriate design or synthesis procedures, and well-justified results. Medium-concern studies provided relevant findings but had limitations such as short duration, incomplete management detail, limited replication, or restricted regional application. High-concern evidence was treated cautiously and used only for local illustration. Confidence was higher when findings were repeatedly supported by long-term experiments, multi-site studies, meta-analyses, or studies with strict reporting standards.

2.6. Analytical Framework

Evidence was evaluated under five core analytical domains: (i) soil health and fertility, including SOC, aggregation, microbial biomass, microbial diversity and nutrient availability; (ii) nitrogen dynamics and biological fixation, including percentage of nitrogen derived from the atmosphere (%Ndfa), total N fixed and residual N benefits to subsequent cereals; (iii) biotic regulation, including pathogen lifecycle disruption, weed seedbank dynamics and pest population trends; (iv) productivity and resilience, including yield response, yield stability and drought-year performance; and (v) environmental performance, including N₂O emissions, carbon footprint and nitrate leaching risks. Economic sustainability and adoption drivers were also considered when reported.

2.7. Limitations

Given the heterogeneity of experimental designs, climatic zones, management practices, and measurement methodologies across studies, direct cross-study quantitative comparison was not always possible. The review therefore provides a weighted narrative synthesis rather than a pooled statistical meta-analysis. Reported N credits, greenhouse gas emissions, and yield responses vary substantially across environments, highlighting the need for region-specific parameterization. The results should be interpreted with stronger confidence were supported by long-term trials, multi-site experiments, meta-analyses, or lower-concern evidence, and with caution where findings are derived from short-term or context-specific case studies.

3. Literature Review

3.1. Plant Biodiversity, Agrobiodiversity and Functional Importance in Agroecosystems

Plant biodiversity is defined as the variety of plants at the genetic, species, and ecosystem levels, and is a foundation for the stability and functionality of terrestrial ecosystems. International literature highlights that biodiversity conservation is not only a matter of “species richness”, but also a matter of functional diversity that directly affects processes such as primary production, nutrient cycling, carbon sequestration, and resilience to disturbances [22].

In rural landscapes, the concept of agrobiodiversity includes both cultivated species/varieties and “accompanying” flora (non-cultivated plants, border/embankment plant communities, wildflower strips), as well as biodiversity that supports critical ecosystem services [9]. Simplification of production systems (e.g., extensive monocultures) tends to reduce the internal ecological regulation of the agroecosystem, while the enhancement of biodiversity is associated with services such as biological control, pollination, and improvement of soil fertility/structure [9].

The biodiversity–production relationship is now also reflected in global composites: biodiversity (in abundance and/or species richness of beneficial organisms) is associated with measurable benefits for production through pollination and biological control of pests, especially when agricultural practices support habitat heterogeneity [8]. At the landscape level, habitat heterogeneity is considered a key mechanism for higher biodiversity in agricultural mosaics, with practices that reduce spatial/temporal heterogeneity being associated with declining trends in many taxa.

A critical axis for plant biodiversity in agricultural production is the maintenance of the diversity of cultivated species and varieties, as well as crop wild relatives, which constitute a pool of genetic resources for resilience to abiotic/biotic pressures. Systematic mapping and assessment of wild relatives has shown significant gaps in in situ and ex situ conservation, documenting the need for targeted collection/protection priorities [21]. At the same time, the “homogenization” of global food supplies, i.e., the increasing convergence of countries on a few key tradable commodities, raises concerns about systemic resilience and food security under climate variability and new risks [20].

In the context of the attached review, crop diversification through crop rotation (e.g., cereal-legume) functions as a practice to enhance agrobiodiversity, with impacts on the functional diversity of the system, on the floristic composition within/around the field plot, but also on soil biodiversity through changes in residue input, nitrogen fixation, and food web structure [18].

Furthermore, synthetic analyses show that agricultural diversification practices (crop diversity, crop rotation, catch crops, organic amendments, reduced tillage, etc.) tend to enhance biodiversity (above- and below-ground) and multiple ecosystem services without necessarily losing yields, when appropriately applied in the local context [1].

Overall, plant biodiversity supports key ecosystem functions and agrosystem resilience. Cereal-legume rotations enhance functional diversity and ecosystem services, highlighting the importance of integrating biodiversity into agricultural systems.

3.2. Benefits of Crop Rotation with Cereals and Legumes

Crop rotation refers to the practice of growing a planned sequence of different crop species in recurring succession on the same land, and it has been the basis of agriculture for centuries. It is of great interest in modern agriculture, which stems from its potential to create more sustainable and flexible farming systems, especially in comparison with conventional monoculture practices, that often heavily rely on external inputs (fertilizers and pesticides) [26]. The diversification of crop rotations, particularly through the integration of cereals and legumes, offers a plethora of interrelated benefits that improve agroecosystems, from soil characteristics to the overall productivity and environmental sustainability. The introduction of diverse crop species, each with its unique physiological traits and interactions with the soil environment, contributes to a better agricultural system.

In summary, cereal-legume rotations improve soil properties, nutrient dynamics, and system sustainability. However, their benefits depend on rotation design and local conditions.

3.3. Soil Health and Fertility

A highly significant advantage of diversified crop rotations, and especially those that include cereals and legumes, is that they improve soil health and fertility. The importance of healthy soil for sustained agricultural productivity and as a basis for numerous ecosystem services is widely recognized [22]. Crop rotations can contribute to the overall improvement of physical, chemical, and biological properties [27]. Crops impact the soil differently, depending on their rooting patterns and the nature of the organic inputs from their residues and rhizodeposition [28]. For example, including legumes can be beneficial because their deep roots, leaf drop, and specific root exudates affect macroaggregate formation and stability [29]. It has been observed that canola and lupin result in greater soil porosity compared to barley, and this is attributed to differences in rooting depth. Stable soil aggregates help with water infiltration, aeration, and resistance to erosion [30]. Crop rotation assists in varying the set of soil nutrients and reducing soil erosion, thus improving soil structure and water holding capacity [31]. This agrees with Liu et al. [28], who state that diversified crop rotation helps the soil structure and that soil aggregation and stability are the main indicators of improved physical properties.

Soil organic carbon (SOC) sequestration is another important benefit. Crop diversification generally leads to an increased SOC, mainly because it adds more varied and often larger quantities of biomass (both above and below the ground) to the soil, compared to monocultures. For example, King and Blesh [32] have found that rotations that include cover crops or perennial species significantly increase the soil’s carbon input and organic matter (SOM) concentrations. Specifically, they observed that crop rotations with cover and perennial species increased C input by 42% and 23%, respectively, while SOC concentrations also increased by 6.3% and 12.5%, respectively, in comparison with grain-only rotations. However, they also noticed that between grain-only rotations, the cereal and legumes combination decreased total C input and SOC when compared to cereal-only rotations. This suggests that it is important which type of functional diversity is applied. Legume residues that consist of a lower C:N ratio may decompose faster but simultaneously stimulate microbial growth that ultimately leads to higher carbon use efficiency, plus the formation of stable mineral-associated soil C complexes. This can potentially compensate for the lower mass production in some scenarios [33]. Another study done on rotations that were intensified with pulses in semi-arid environments found that after 8 years, soil organic carbon increased from a baseline of 10.3 g/kg to 11.2 g/kg across various rotations (including chickpea–wheat (Cicer arietinum-Triticum aestivum), lentil–wheat (Lens culinaris-Triticum aestivum), and pea–wheat (Pisum sativum-Triticum aestivum)) while there wasno significant difference among these pulse-based rotation systems themselves. This shows a general positive trend regarding SOC under diversified systems in comparison with the initial state, even when the specific pulse crop is not capable of creating major differences in SOC accumulation in the particular context of the study [14].

Crop rotation also improves nutrient cycling and availability. Legumes play a central role, through the process of biological nitrogen fixation (BNF), which enriches the soil nitrogen availability and reduces the need for synthetic fertilizers [34,35]. This is referenced as “N–credit”, and it is a recognized benefit on a wide scale. An example of this is provided by Preissel et al. [36], where it was estimated that N fertilization for crops that follow after grain legumes can be reduced by 23–31 kg N/ha. Similarly, a meta-analysis that was published by Zhao et al. [29] demonstrated that the yield under legume-based rotations was increased by 14% more than without legumes, and this was largely attributed to increased N input. A study by Ghosh et al. [37] found that including mung bean in a rice–wheat rotation (Oryza sativa-Triticum aestivum) resulted in increased amounts of available nitrogen and phosphorus in the soil, which later impacted the base crop productivity. Also, different species of crops have completely different depths of root systems and different patterns in absorbing nutrients. Potentially, that can lead to more efficient utilization of the soil nutrient pools. Crops with deeper roots, like alfalfa (Medicago sativa), can access nutrients from deeper soil layers and bring them closer to the surface, where they can be beneficial for the successive shallower-rooted crops [38,39]. Some legumes, like white lupin and faba bean, can also mobilize the soil-bound phosphorus through root exudates. This can lead to better availability, both for themselves and the subsequent crops.

Crop rotation also benefits the biological health of the soil, whichmeans the abundance and diversity of the microbial profile. Utilizing different crops provides a wider range of organic substrates (both residues and root exudates) into the soil, which then supports an active and well-structured soil microbial community. This activity helps with nutrient mineralization, organic matter decomposition, and the suppression of diseases. Another benefit is that crop rotation reduces the outbreak of pests and diseases, mainly because it results in a healthier and more competitive soil microbiome. A meta-analysis of 76 studies that was performed by Liu et al. [40] noticed that crop rotation significantly increased soil microbial biomass carbon (MBC) by 13.43%, and microbial biomass nitrogen (MBN) 15.84% when compared to a continuous monoculture. Additionally, they reported that the rotation increased the bacterial Shannon’s diversity index by 7.68%.

Soil enzymatic activity is another key indicator of soil biological functioning that reflects microbial-mediated nutrient cycling processes. Enzymes such as dehydrogenase, urease, phosphatase, and β-glucosidase are directly involved in the transformation of carbon, nitrogen, and phosphorus in soils [41,42]. Studies have shown that crop rotations, particularly those including legumes, can significantly enhance soil enzyme activities due to increased organic inputs and simulation of microbial communities [43,44]. For example, urease and phosphatase activities are often higher in legume-based systems, reflecting improved nitrogen and phosphorus cycling, while dehydrogenase activity is commonly used as an indicator of overall microbial metabolic activity [45,46]. These responses are closely linked to residue quality and root exudation patterns, highlighting that cereal-legume rotations not only increase microbial biomass but also enhance the functional capacity of soil microbial communities [1,47].

Despite the generally positive effects of cereal-legume rotations on soil properties, these outcomes are not universal and are highly content-dependent. For instance, soil organic carbon (SOC) is influenced by factors such as biomass input, residue management, and climatic conditions [28,32]. In some cases, legume-based rotations may result in lower total carbon inputs compared to cereal-dominated systems, potentially constraining long-term SOC accumulation [32]. Furthermore, the relatively low C:N ratio of legume residues can accelerate decomposition rates, which, while enhancing microbial activity and nutrient cycling, may limit long-term carbon stabilization under certain conditions [28,33].

The main findings from representative studies examining the effects of cereal-legume rotations on soil properties and soil biological activity are summarized in

Table 1. Effects of cereal-legume rotations on soil properties.

Region/Agroecosystem	Rotation System	Soil Indicator	Reported Effect	References
Australia	diversified crop rotations	Soil structure	Improved soil aggregation and porosity	[30]
USA	rotations with cover crops/perennials	Soil organic carbon	SOC increased by 6–12%; C input increased by 23–42%	[32]
Global synthesis	diversified rotations	Soil physical properties	Improved soil aggregation and structural stability	[28]
Global meta-synthesis	crop rotation vs monoculture	Microbial biomass	MBC + 13.43%; MBN + 15.84%	[40]
Europe	grain legume–cereal rotations	Nitrogen dynamics	N fertilizer requirement reduced by 23–31 kg N ha−1	[36]
China	legume-based rotations	Crop productivity/N dynamics	Yield increase ~14% due to higher N input	[29]
Indo–Gangetic Plain	rice–wheat–mungbean (Oryza sativa-Triticum aestivum-Vigna radiata)	Soil nutrients	Increased available N and P in soil	[37]
Semi-arid environments	pulse–wheat rotations	Soil organic carbon	SOC increased from 10.3 to 11.2 g kg−1 after 8 years	[14]

.

Across the studies summarized in Table 1, increases in soil organic carbon (SOC) and microbial biomass are consistently reported, although their magnitude varies depending on rotation duration and environmental conditions. SOC gains are generally moderate, reflecting the slow accumulation and stabilization of organic matter, whereas microbial biomass shows more pronounced and rapid increases, indicating a faster biological response to diversified residue inputs. This contrast suggests that soil biological properties respond earlier than soil carbon stocks, highlighting the importance of distinguishing between short-term biological activity and long-term carbon sequestration processes when evaluating system performance.

Overall, cereal-legume rotations enhance soil structure, nutrient availability, and biological activity. Microbial responses are often faster than SOC changes, and outcomes depend on management and environmental conditions.

3.4. Integrated Pest, Disease, and Weed Management

Diversified crop rotations are widely recognized as a core preventive tool within integrated pest management (IPM), because they introduce temporal diversity that disrupts pest, pathogen, and weed life cycles and lowers the probability of recurrent outbreaks in successive seasons [48,49]. In cereal-legume rotations, functional contrasts between crop types help reduce carry-out inoculum and pest populations, while also improving soil biological functioning processes that can indirectly enhance plant health and tolerance to biotic stress [49,50]. Crop rotation is also a well-established weed management strategy; by alternating crops with different sowing dates and disturbance regimes, rotation reduces weed seedbank replenishment and shifts communities away from dominance by a few highly adapted species [51,52,53]. As a result, diversified rotations can enable lower reliance on synthetic chemical inputs, including herbicides, while maintaining agronomic performance, particularly when combined with complementary cultural practices [54,55,56].

Crop rotation reduces pests, diseases, and weeds by disrupting life cycles. Its effectiveness depends on crop sequence, rotation length, and local conditions.

3.4.1. Disease Management

The main mechanism of disease management in crop rotations is the disruption of pathogen life cycles, especially for host-specific, residue-borne, and soil-borne pathogens. Continuous monoculture permits the accumulation of the pathogen inoculum in the soil and in the crop residues. By rotating non-host crops, we can effectively reduce pathogen survival, especially for those that have limited host ranges or survival structures. For example, in wheat (Triticum aestivum), a 1–year break can reduce diseases like Septoria leaf and glume blotch under low severity. Meanwhile, a 2–year break provides better control for more severe conditions, as observed in the study of [28,57]. In a similar study, it was demonstrated that blackleg disease of canola (Leptosphaeria maculans) was significantly mitigated by four–year crop rotations in combination with the use of resistant cultivars. The highest blackleg severity was measured in continuous canola cultivation, and it gradually decreased as the break between canola (Brassica napus) crops increased. By introducing other legumes, like field pea (Pisum sativum) or flax (Linum usitatissimum) between canola crops, it also seemed to reduce the severity of the disease [58]. For other diseases that can be more persistent and with long living resting spores (such as clubroot, Plasmodiophora brassicae in brassicas or Aphanomyces root rot, Aphanomyces euteiches in peas and lentils), rotation on itself might be somewhat insufficient, but it still remains an important part of IPM. Oftentimes, if combined with resistant varieties, it can achieve effective control [40,59]. A study by Peng et al. [60] suggested that a rotation of more than two years could reduce P. brassicae resting spores and clubroot impact.

3.4.2. Weed Management

Crop rotation changes the selection pressures and creates less favorable conditions for specific weed species. That prevents their domination and assists with their suppression. It has been consistently proven that diversified systems reduce weed populations compared to monocultures. The mechanisms behind this are many. Different crops compete in a different way with weeds for resources. Weed emergence patterns are getting disrupted by changing planting and harvesting times. In addition, the rotation facilitates the utilization of various herbicide modes of action, which mitigates the evolution of herbicide resistance. A long-term study by Davis et al. [55] in Iowa noticed that a diverse rotation that utilized maize (Zea mays), soybean (Glycine max), cereals, and alfalfa (Medicago sativa), maintained the same weed seed bank densities as a standard rotation of maize–soybean (Zea mays-Glycine max), while using 90% less herbicides. Another benefit is that crop rotation combined with specific cultural practices (e.g., higher seeding rates, narrow row spacing, precision placement of fertilizers) can assist with weed control. Harker et al. [61] noted that diverse rotations (like barley (Hordeum vulgare) that is cut for silage and fall–seeded winter crops) that have omitted herbicides in 3 of 5 years, have wild oat (Avena fatua) densities similar to herbicide-treated controls. It appears that by including perennial crops (e.g., alfalfa), the efficacy increases. Specifically, a study demonstrated that rotations with 3 years of alfalfa had the lowest frequency of resistance to herbicides in wild oats. This was attributed to decreased use of herbicides and better crop competition [62].

3.4.3. Pest Management

Similar to diseases, crop rotation disrupts pest life cycles by altering the availability of host plants. Studies show that techniques like intercropping can improve pest management, mainly because they increase the habitat’s complexity, therefore increasing the populations of natural enemies [63]. Brooker et al. [15] mention different studies that show that predator variety increases in diverse systems, such as apple orchards (Malus domestica) with aromatic interplants. Additionally, crop rotation affects pest occurrence. A multi-year study that was conducted in spring wheat (Triticum aestivum) observed that, while rotation did not consistently reduce wheat midge (Sitodiplosis mosellana) damage overall, specific years showed lower damage in more diverse rotations [64]. Another review on crop rotation and diversification (CRD) also mentions that by disturbing pest life cycles, CRD can prevent their accumulation to levels that are economically damaging. Introducing non-host crops makes egg-laying sites unsuitable for specialist pests, thus reducing reproduction [39].

3.5. Crop Productivity

Diversified crop rotations have been extensively studied mainly because they consistently benefit crop productivity and overall system yield, in comparison to simplified monocultures or short rotations. This benefit arises from the cumulative effects of improved soil health, better nutrient cycling, and reduced pest pressure, as discussed previously. The productivity gains have been quantified by a plethora of studies. For example, a meta-analysis covering 45 studies in China found that crop rotation increased the subsequent crop yields by an average of 20.1% when compared with continuous monoculture practices. This effect, expectedly, varied between regions and crop species. Specifically, rotations that included legumes had a 14% higher increase than those without legumes. This positive effect was even stronger when grain legumes preceded the study crops, where the yield of the succeeding crops increased by 27% [29]. In another extensive study of 32 long-term experiments across Europe and North America, it was shown that crop rotational diversity improved grain yields of small grain cereals and maize (Zea mays), with gradually increasing benefits. For example, after only 5 years, CRD increased short-term grain yield by 0.36 t/ha for spring small grain cereals, 0.62 t/ha for winter small grain cereals, and 2.26 t/ha for maize (Zea mays), in comparison with monoculture baselines at a low N input. These benefits further increased in the span of 35 years [65]. It is also noted that yields in rotations are typically 10% higher than monocultures, and can go up to 25% higher in seasons with drought [66].

By including legumes in the rotation, we can often directly boost the yield of the following cereal. Ghosh et al. [37] reported that in the Indo–Gangetic plain, the inclusion of mung bean in a rotation of rice (Oryza sativa) and wheat (Triticum aestivum) increased the rice grain yield by 10–14%, while in maize (Zea mays) and wheat rotation (Triticum aestivum) increased the wheat (Triticum aestivum) grain yield by 5–11%. Another observation was that by replacing wheat (Triticum aestivum) with chickpea (Cicer arietinum) in a rice–wheat system (Oryza sativa-Triticum aestivum), the rice yield was improved by 5–8%. In a previously mentioned study by Liu et al. [14], it was found that across 4 rotation cycles, a pea–wheat system (Pisum sativum-Triticum aestivum) increased the protein-based system yields by 26–66% compared to wheat (Triticum aestivum) monoculture, and that wheat (Triticum aestivum) grain yields were 8–27% and 5–28% higher when preceded by pea (Pisum sativum) and lentil, respectively. Jalli et al. [64] observed in Finland that a diversified 4–year rotation (spring wheat–turnip rape–barley–pea) improved spring wheat (Triticum aestivum) yield by up to 30% in no-tillage and 13% under plowing in comparison with monoculture.

System resilience, which is often indicated by yield stability, is another important factor. It is known that diversified systems tend towards more stability. Gaudin et al. [67] found that by increasing crop diversity, weather variations are alleviated and yield stability is improved. Liu et al. [14] also reported that a pea–wheat rotation (Pisum sativum-Triticum aestivum) showed the smallest variation in protein-based system yield, which indicates greater stability.

However, the productivity benefits associated with cereal-legume rotations are not uniform across all agroecosystems. Yield responses are strongly influenced by environmental conditions, crop species, and management practices [28,29]. For example, in water-limited environments, legumes may reduce soil moisture availability for subsequent crops, potentially offsetting nitrogen-related benefits [28]. Similarly, in high-input systems where nutrient availability is already optimized, the relative yield advantage of rotations may be reduced [65]. Therefore, while cereal-legume rotations often enhance productivity and yield stability [29,67], these outcomes should be interpreted within a context-specific framework rather than generalized across systems.

A synthesis of representative studies evaluating the effects of cereal-legume crop rotations on crop productivity and yield stability is illustrated in

Table 2. Effects of cereal-legume crop rotations on crop productivity and yield stability.

Region	Rotation System	Main Results	References
China	Crop rotations (legume vs. non-legume)	Yield increased by 20.1% on average; legume rotations showed ~14% higher yields, up to 27% increase when legumes preceded crops	[29]
Europe & North America	Diversified crop rotations	Yield increases of 0.36 t ha−1 (spring cereals), 0.62 t ha−1 (winter cereals), 2.26 t ha−1 (maize (Zea mays)); benefits increased over time	[65]
Indo–Gangetic Plain	Rice–wheat–mungbean (Oryza sativa-Triticum aestivum-Vigna radiata); maize–wheat rotations (Zea mays-Triticum aestivum)	Rice yield increased 10–14%; wheat yield increased 5–11%	[37]
Semi-arid environments	Pea–wheat (Pisum sativum-Triticum aestivum) and lentil–wheat rotations	Wheat yield increased 8–27% (Pisum sativum) and 5–28% (lentil); system productivity increased 26–66%	[14]
Finland	Diversified 4-year rotation (wheat–rape–barley–pea)-(Triticum aestivum-Brassica napus-Hordeum vulgare-Pisum sativum)	Wheat yield increased up to 30% (no-tillage) and 13% (plowing)	[64]
North America	Increased crop diversity	Improved yield stability under climate variability	[67]
Semi-arid environments	Pea–wheat rotation (Pisum sativum-Triticum aestivum)	Reduced yield variability and increased system stability	[14]
Global synthesis	Crop rotations vs. monoculture	Yields typically ~10% higher, up to 25% higher under drought conditions	[66]

.

According to the studies summarized in Table 2, cereal-legume rotations generally result in increased crop yields compared to monocropping systems, although the magnitude of improvement varies considerably across different conditions. Yield responses appear to be more pronounced under low-input or stress-prone environments, where biological nitrogen fixation and improved soil structure provide greater relative benefits. In contrast, under high-input systems, yield advantages are often marked, suggesting that the effectiveness of rotations depends strongly on baseline resource availability and management intensity. This variability highlights the importance of interpreting productivity outcomes within their specific agronomic and environmental context.

Cereal-legume rotations generally improve yield and stability, especially under low-input conditions. Effects are context-dependent and vary with management intensity.

3.6. Environmental Impact and Trade-Offs

The main environmental benefits that crop rotations offer are reduced greenhouse gas (GHG) emissions and a smaller carbon footprint, compared to conventional monoculture systems. This is due to the minimized reliance on chemical fertilizers. It is well known that agriculture contributes vastly to GHG emissions, with the major concern being nitrous oxide (N₂O) from applying nitrogen fertilizers [28,39]. Rotations that are based on legumes directly tackle this by reducing the need for synthetic N fertilizers through biological nitrogen fixation (BNF). Studies consistently show lower N₂O emissions from legume crops in relation to N-fertilized non-legumes. For instance, Schwenke et al. [68] found that cumulative N₂O emissions from N-fertilized canola (385–624 g N₂O–N ha⁻¹) were significantly larger than from different grain legumes like chickpea (Cicer arietinum), faba bean (Vicia faba), and field pea (127–166 g N₂O–N ha⁻¹), with 75% of legume N₂O losses occurring post-harvest. Moreover, Lemke et al. [69] mentioned that N₂O losses from N-fertilized canola or wheat were generally higher than those from unfertilized pea. Biernat et al. [70] also reported lower N₂O emissions from organic rotations with legumes (0.7 kg N₂O–N ha⁻¹ yr⁻¹) in comparison to conventional N-fertilized rotations (2.1 kg N₂O–N ha⁻¹ yr⁻¹). However, it appears that these emissions can be influenced by how legume residues are managed and what tillage practices are taking place. Li et al. [71] found that brown-manuring legumes (retaining all biomass) led to higher N₂O emissions (e.g., 195 g N₂O–N ha⁻¹ yr⁻¹ during the legume phase) compared to product-removed systems (113 g N₂O–N ha⁻¹ yr⁻¹), adding that tillage tended to increase emissions in the product-removed systems. Interestingly, Matthews et al. [72] noticed that in their no-till systems, rotations that integrate both legumes and livestock exhibited higher N₂O emissions (0.31–0.42 kg N₂O–N ha⁻¹ yr⁻¹) than cash crop-only systems (0.14 kg N₂O–N ha⁻¹ yr⁻¹), with the occurrence of emission hotspots after off-season rainfall, which indicates that there are complex interactions.

The carbon footprint of cropping systems measures the total GHG emissions per unit of product area. It appears that it is also positively impacted. A key factor in this is that legume-based systems require less N fertilizer. Gan et al. [73] noticed that durum wheat had a 20% lower carbon footprint when preceded by a pulse crop, and (Gan et al. [74], mentioned a 34% reduction for durum wheat after two consecutive pulse crops, compared with cereal monoculture. Furthermore, as mentioned above, diversified rotations improve SOC sequestration. Many studies mention that SOC gains over time can significantly offset carbon emissions attributed to crop inputs, thereby lowering the overall carbon footprint of the rotation [28,32,75]. While Costa et al. [76] advise that a possible trade-off of legume cultivation can be higher nitrate leaching, the overall environmental profile, and particularly concerning GHG emissions, is often improved.

In addition to nitrous oxide emissions, carbon dioxide fluxes represent a major component of the greenhouse gas balance in agricultural systems [76,77]. CO₂ emissions in cropping systems are primarily associated with soil respiration, organic matter decomposition, and indirect emissions from agricultural inputs such as fertilizer production and field operations [77]. Cereal-legume rotations can influence CO₂dynamics both directly and indirectly. On the other hand, increased soil organic carbon (SOC) sequestration under diversified rotations can act as a carbon sink, partially offsetting CO₂ emissions [28,32]. On the other hand, enhanced microbial activity and residue decomposition may increase short-term CO₂ fluxes from soils [42]. Therefore, the net effect of cereal-legume rotations on CO₂emissions depends on the balance between carbon inputs, decomposition rates, and management practices [32,40,59]. This highlights the importance of considering CO₂within a whole-system carbon balance framework rather than as an isolated indicator [76].

Overall, the environmental performance of cereal-legume rotations reflects a balance between benefits and trade-offs. While reductions in synthetic use and associated greenhouse gas emissions are well documented [28,39], these systems may also present environmental risks under certain conditions. For instance, the decomposition of nitrogen-rich legume residues can increase N₂O emissions, particularly under high soil moisture or following rainfall events [68,71], while nitrate leaching may occur when nitrogen release is not synchronized with crop uptake [76]. These findings indicate that environmental benefits are highly dependent on management practices such as residue handling, tillage, and crop sequencing [71] and should not be assumed to be universally positive.

While these trade-offs are acknowledged, their implications need to be considered more explicitly within the overall sustainability assessment. In particular, the potential increase in N₂O emissions and nitrate leaching under specific management and environmental conditions highlights that the environmental performance of cereal-legume rotations cannot be evaluated solely based on reduced fertilizer inputs [28,71,76]. Instead, these systems should be assessed using an integrated framework that balances benefits (reduced synthetic N use, improved soil carbon) against potential risks (e.g., nitrogen losses) [28]. This reinforces the importance of management-dependent optimization, including synchronization of nitrogen release with crop demand, appropriate residue management, and reduced soil disturbance to minimize unintended environmental impacts [68,71]. Therefore, the sustainability of cereal-legume rotations should be interpreted as context-dependent, requiring site-specific design and management to ensure that environmental benefits outweigh potential trade-offs [1,28].

A summary of selected studies assessing the influence of cereal-legume crop rotations on the environment (greenhouse gas emissions and carbon footprint) is provided in

Table 3. The influence of cereal-legume crop rotations on the environment.

System	Indicator	Main Results	References
Legumes vs. N-fertilized canola	N2O emissions	Canola: 385–624 g N2O–N ha−1 vs. legumes: 127–166 g N2O–N ha−1 (lower emissions in legumes)	[68]
N-fertilized crops vs. pea (Pisum sativum)	N2O emissions	Higher emissions in fertilized wheat/canola compared to unfertilized pea (Pisum sativum)	[69]
Organic legume rotations vs. conventional	N2O emissions	0.7 vs. 2.1 kg N2O–N ha−1 yr−1 (lower in legume systems)	[70]
Brown manuring vs. residue removal	N2O emissions	Higher emissions when biomass is retained (195 vs. 113 g N2O–N ha−1 yr−1)	[71]
Mixed systems vs. cash crops	N2O emissions	Higher emissions in mixed systems (0.31–0.42 vs. 0.14 kg N2O–N ha−1 yr−1)	[72]
Pulse–wheat vs. monoculture	Carbon footprint	20% reduction in durum wheat	[73]
Double pulse–wheat vs. monoculture	Carbon footprint	34% reduction	[74]
Diversified rotations	SOC sequestration	Increased SOC offsets carbon emissions	[28,32,75]
Legume systems	Environmental trade-offs	Possible increase in nitrate leaching	[76]

.

The environmental indicators summarized in Table 3 reveal a complex balance between benefits and potential trade-offs associated with cereal-legume rotations. While reductions in synthetic nitrogen inputs are frequently linked to improved environmental performance, increases in nitrogen availability from legume residues may, under certain conditions, lead to higher N₂O emissions and nitrate leaching. These contrasting responses indicate that environmental outcomes are highly dependent on management practices and environmental conditions, rather than being uniformly positive. As a result, evaluating environmental performance requires consideration of multiple interacting processes rather than reliance on single indicators.

Cereal-legume rotations can reduce inputs and improve environmental performance, but trade-offs (N₂O, leaching) may occur. Outcomes are strongly management-dependent.

3.7. Role of Legumes in Cereal-Based Crop Rotation Systems

3.7.1. Mechanisms of Biological Nitrogen Fixation

Legumes are very important in improving the sustainability and productivity of cereal-based crop rotation systems, mainly because of their unique ability to fix atmospheric nitrogen (N₂), which supplies the soil and benefits the subsequent crops. The biological nitrogen fixation (BNF) constitutes its rotational value, as it reduces the reliance on synthetic nitrogen fertilizers and their associated environmental burdens significantly. However, the efficiency of BNF is not steady, as it varies considerably between legume species and is greatly influenced by environmental conditions, soil fertility, and specific management practices. A study on faba beans (Vicia faba L.) found that the percentage of N derived from the atmosphere (%Ndfa) ranged widely from 78% to 93%. This indicated that conventional systems, maybe because of optimized plant health and thus higher N demand, sometimes exhibited greater %Ndfa and consequently higher quantities of N fixed (qBNF)—averaging 334 kg N ha⁻¹ in aboveground biomass compared to 255 kg N ha⁻¹ in organic systems [78]. Another study that analyzed the performance of legumes in Sub-Saharan Africa (SSA) mentioned that species like soybean and groundnut often have stronger residual N effects on subsequent maize (Zea mays) than cowpea (Vigna unguiculata) [79]. It seems that the actual amount of N fixed is linked to the legume’s growth and biomass accumulation. For example, this was demonstrated by a study that showed that legume inclusion, specifically peanut preceding wheat under no fertilization, resulted in significantly higher wheat yields, which implies a considerable N contribution [40]. Additionally, Nemecek et al. [77] mentioned that for peas, a N benefit of about 20 kg N/ha to the succeeding crop is often found, and this allows for reduced N fertilizer application to the following cereal. Efficient BNF leads directly to observable benefits, such as reduced fertilizer costs for farmers and a lowered risk of N losses to the environment, such as nitrous oxide emissions or nitrate leaching.

3.7.2. Other Benefits in the Agroecosystem

Apart from their important role in nitrogen fixation, legumes provide other various beneficial effects that contribute to the agroecosystems’ overall health and functionality. By including them in crop rotations, we can improve the soil structure and the biological activity. It is noted that legume residues, which usually have a lower carbon–to–nitrogen (C:N) ratio compared to cereal straw, decompose more easily [28]. This rapid decomposition can stimulate soil microbial populations and activity, which then leads to better nutrient cycling and contributes positively to soil organic matter (SOM) dynamics in the long term. Franke et al. [79] discuss in their study, that while legumes may sometimes produce less total biomass than high-yielding cereals, the increased productivity of the entire cropping system (including the boost in the yield of the subsequent cereal crop) can result in a greater overall return of organic residues to the soil. Others have found that legume–wheat rotations increased soil ecosystem multifunctionality by 0.8 times in the topsoil, while at the same time maintaining soil organic carbon stocks, even with lower C and N inputs compared to maize–wheat systems (Zea mays-Triticum aestivum) [40]. Also, legumes are essential in breaking pest and disease cycles, which was previously discussed. Their ability to mobilize soil-bound phosphorus through the exudation of organic acids from their roots is another significant advantage, which makes this essential nutrient more available for both the legume itself and subsequent crops [79]. The characteristic root architectures of many legume species (often deeper and more branched than cereals) also help with soil exploration, improve soil aeration and water infiltration, and can ease compaction. Nemecek et al. [77] also mentions that the diversification of crop rotations through legume inclusion often leads to reduced pesticide use, due to these break–crop effects.

3.7.3. Criteria for Selecting Legume Species and Varieties

The effective integration of legumes in cereal-based rotations depends on the careful and informed selection of the appropriate legume species and varieties, which should be chosen on a specific agroecological context, soil type, climatic conditions, and the general farming system. Some criteria that affect this process include the legume’s inherent biological nitrogen fixation (BNF) potential, its typical biomass production, which influences organic matter input, the duration of its growth cycle, which affects its fit within the rotation, and its adaptation to local soil (e.g., pH, texture) and climatic (e.g., rainfall patterns, temperature regimes) characteristics. Another important factor is water use efficiency, especially in arid or semi-arid regions where residual soil moisture for the following crop is of utmost importance [28]. In the study of Franke et al., [79] a holistic review is provided for SSA, which emphasizes that the effects of legumes on subsequent cereal yields differ significantly between species. For example, soybean and groundnut frequently showed stronger positive impacts on maize (Zea mays) yields than cowpea, and this shows differences in N fixation, residue quality, and water extraction patterns. Liu et al. [59] showed that in the North China Plain, peanut as a pre-crop led to a stronger wheat yield advantage compared to maize (Zea mays), and especially under no fertilization. The intended end use of the legume, whether it is for grain, forage, or as green manure, also directs the choice, as does its market value and the farmer’s capacity to manage it effectively. Furthermore, as Nemecek et al. [77] discussed for the European systems, the choice between, for instance, spring-sown peas versus autumn-sown winter peas can differently affect factors like nitrate leaching risk, due to variations in soil cover duration and rooting depth. Equally important is the resistance or tolerance to prevalent local pests and diseases, in order to ensure the legume phase itself is productive and does not unintentionally cause problems for subsequent crops. Therefore, a holistic assessment weighing all of these multiple interacting factors is essential to maximize the diverse benefits of legume integration.

3.8. Design and Implementation of Crop Rotation Systems

3.8.1. Design Parameters

As stated above, the effective design of cereal-legume crop rotation systems must take into account multiple interacting factors. Examples are the specific agroecological context, which includes climate (rainfall amount and distribution, temperature) and soil characteristics (type, fertility, water-holding capacity), which influence the suitability of different legume and cereal species. Prioritizing yield maximization, soil fertility improvement, pest management, or economic returns also heavily influences the design choices [80]. The selection and sequence of crops are of great importance. This includes the choice of appropriate legume species (e.g., faba bean, pea, soybean, peanut, mung bean), as studied by Dabessa and Debala [81], and cereal varieties, considering their growth cycles, rooting depths, nutrient requirements, and potential for positive or negative allelopathic interactions. The duration of the rotation cycle (e.g., biennial, triennial, or longer) and the proportion of legumes within the rotation are basic design elements that affect the nitrogen dynamics, pest cycles, and overall system productivity. For example, Costa et al. [76] reviewed LCA studies where rotation length was a key variable. Management practices such as fertilization strategies for both legume and cereal phases, tillage methods, residue management, and irrigation (if applicable) must be incorporated into the rotation design. Additionally, the potential for intercropping legumes with cereals offers another layer of design complexity that aims to optimize resource use efficiency through complementary plant interactions [82]. Another factor that affects farmer adoption and the long-term success of the designed rotation is the market access and the economic viability of the chosen legume crop [80].

3.8.2. Comparative Analysis of Different Crop Rotation Models

A variety of crop rotation models that incorporate cereals and legumes have been evaluated in different agricultural landscapes and provide a broad spectrum of outcomes based on their composition and management intensity. Short rotations, like a simple biennial legume–cereal sequence (e.g., faba bean–wheat or soybean–maize), are common and often show immediate benefits in terms of nitrogen supply to the cereal and subsequent yield increases. Yigezu et al. [80] reported significant yield and gross margin improvements in faba bean–wheat rotations over wheat monocropping in Morocco. Likewise, Dabessa and Debala [81] found that soybean–maize rotations (Glycine max-Zea mays) in Ethiopia provided more steady maize (Zea mays) yields and improved various soil fertility parameters, like the available P and total N over five years, specifically when both crops received appropriate amounts fertilization, with the highest maize (Zea mays)grain yield recorded from soybean–maize rotation (Glycine max-Zea mays) where both components were fertilized. Longer and more complex rotations that often involve multiple cereal types, different legume species, and sometimes other break crops like oilseeds (e.g., spring wheat–turnip rape–barley–pea), can offer more complete benefits in terms of pest and disease cycle disruption and continuous soil health improvement [28,64]. A study compared several legume–wheat rotations (peanut–W, mung bean–W, soybean–W, adzuki bean–W) against a conventional maize–wheat system (Zea mays-Triticum aestivum) over seven years, found that all legume–wheat systems provided a wheat yield advantage (52% on average without fertilization, 26% with fertilization) and better soil ecosystem multifunctionality [40]. Another significant factor appears to be the choice of legume species within those longer rotations. For instance, the same study observed a stronger positive effect on wheat yield stability after peanut than the effect after maize (Zea mays). Intercropping models, where cereals and legumes are grown simultaneously, represent another strategic approach. Zhao et al. [82] showed that intercropping Glycine max with Zea mays had a particularly positive outcome, where G. max fixed more N₂ and Z. mays obtained more transferred N compared to other tested legume–cereal combinations, which further showed the importance of species-specific interactions. The comparison between these models reveals that, while legume inclusion is generally beneficial, the magnitude and type of benefits are highly dependent on the specific crops that are chosen, the rotation length, the management intensity (this includes fertilization), and the local environmental context.

3.8.3. Interaction of Crop Rotation with Soil Conservation Practices

When crop rotations are combined with soil conservation practices, the benefits multiply. These include reduced tillage (including no-till), crop residue retention (mulching), etc. The practices are central to conservation agriculture, and their purpose is the minimization of soil disturbance, maintenance of soil cover, and improvement of the soil organic matter. Crop rotation adds to these goals by providing different residue types and varying the timing of soil cover and root system architectures [28]. For example, a study demonstrated that maize–peanut rotation (Zea mays-Arachis hypogaea) significantly increased the maize (Zea mays) root biomass and yield, while straw mulching (which is a form of residue retention) increased soil total organic carbon (TOC), active organic carbon (AOC), and microbial biomass carbon (MBC) [83]. Field evidence from a two-year rotation system including Triticosecale-Pisum sativum followed by sunflower in central Greece demonstrated that no-tillage practices, particularly when planting was performed parallel to the contour, significantly improved sunflower growth and nitrogen-related parameters. Plant height reached up to 85–86 cm under no-tillage compared to 64–80 cm under conventional tillage. Leaf area index (LAI) was higher under no-tillage, reaching 3.9–4.01 m² m⁻², while total plant nitrogen content increased up to 4.43%. Protein content was also enhanced (up to 27.7%), and N-uptake reached 265 kg ha⁻¹ in the second year under no-tillage parallel to contour planting. These findings indicate that the integration of legume-based winter cover crops with conventional tillage practices enhances dynamics, biomass development, and overall crop performance in Mediterranean agroecosystems [84]. Another study, which analyzed rotations under conservation agriculture principles, found that soil carbon increased significantly over a 20–year period across all tested rotation systems [72]. In addition, it has been shown that the yield benefit of a diversified 4–year rotation for spring wheat was greater under no-tillage (up to 30% increase) in comparison to conventional plowing (13% increase), which suggests a synergistic effect.

3.9. Economic Analysis and Sustainability of Crop Rotation Systems

The implementation of cereal-legume rotations can often lead to economic advantages, and it contributes significantly to the overall sustainability of farming systems. It has been demonstrated that faba bean–wheat rotations in Moroccan dry areas provided higher yields, gross margins (US$146/ha higher from subsequent wheat), and increased household consumption of both wheat and faba beans in relation to wheat monocropping, even under a biennial rotation. The study also noted that the simultaneous adoption of rotations and improved faba bean varieties could lead to a two-year average gross margin of US$537/ha, which was 48% higher than wheat monocropping [80]. This explains the economic motive for the promotion of such systems, especially when they are combined with improved legume genetics.

From the perspective of sustainability, the reduced reliance on synthetic nitrogen fertilizers in legume-based rotations, as pointed out by Nemecek et al. [77] and Costa et al. [76], directly lowers production costs and alleviates environmental impacts associated with fertilizer manufacture and use, such as GHG emissions and energy consumption. Even though Yigezu et al. [80] noticed that Moroccan farmers in rotations sometimes used more N fertilizer on the subsequent wheat (which goes against the expectations of N–credit utilization), the overall system benefits (involving yield gains and reduced costs for other inputs, like DAP and pesticides) still rendered rotations more profitable. Life Cycle Assessment (LCA) studies often suggest that legume incorporation reduces overall environmental burdens, although trade-offs, like potential nitrate leaching, need careful management [76]. The long-term maintenance of soil fertility and productivity with legume rotations is critical for the long-lasting sustainability of agricultural systems [81].

While economic sustainability is recognized as a key component of agroecosystem performance, its evaluation remains extensively addressed compared to biophysical and environmental aspects. In the context of cereal-legume rotations, economic outcomes are influenced by a combination of yield stability, input cost reduction, market conditions, and risk management [77,80]. Reduced dependence on synthetic nitrogen fertilizers can lower production costs, while improved soil fertility and system resilience contribute to more stable yields over time [76,77]. In addition, short-term economic returns may not always fully capture long-term benefits associated with improved soil health and reduced environmental externalities [28]. Therefore, a comprehensive assessment of cereal-legume rotations should integrate economic indications with agronomic and environmental metrics, recognizing that adoption decisions are ultimately driven by both profitability and risk considerations [80].

3.10. Utilization of Plant Biodiversity for Resilient Cereal-Legume Rotation Systems

In addition to selecting crop sequences, the intentional use of plant biodiversity at the species, varietal, and landscape levels provides an effective means to enhance the performance and stability of cereal-legume rotations. Biodiversity-based management involves the strategic integration of functionally complementary plant elements (e.g., cereals, legumes, cover crops, and non-crop vegetation) to enhance essential agroecosystem processes such as nutrient cycling, pest and disease regulation, and resource-use efficiency, while minimizing reliance on external inputs [85,86].

Within-crop level by increasing genetic diversity within crops, for example, with cultivar mixtures or multilines, one can decrease the spread of epidemics and diminish fungicide requirements, especially in the case ofairborne diseases present or when host specialization is prevalent [87]. A well-referenced, large-scale case is the rice varietal mixtures used in Yunnan province of China, where there were significantly fewerrice blast changes while maintaining or increasing current yields than found in monocultures [88]. Similar theories can also be used to exploit common cerealrotation components (e.g., wheat, barley, oats) by including genotypes with different resistance genes, phenology, canopy architecture, or competitive traits to overcome seasonal variations and pathogen adaptation [87].

At the genetic-resources level, crop wild relatives (CWR) and farmer-managed landraces provide key reservoirs of adaptive variationfor developing cultivars that can perform consistently under both climatic and biotic stress. The introgression of wild relatives’ traits to contemporary cultivars has a long tradition, but the systematic use remains hampered by pre-breeding seed bottlenecks, cross-compatibility issues, and insufficient knowledge about useful alleles [89,90]. Focused programs that specifically gather, preserve, and make CWR available are thus increasingly framed as key elements of adaptation to climate change in agriculture [91]. The risks and potential for CWR conservation are revealed by global evaluations, which show that numerous CWR taxa of high breeding value are insufficiently conserved ex situ and are subjected to habitat loss at the same time.Castañeda-Álvarez et al. imply that efforts devoted to conservation planning should advance hand in hand with increasing exploitation.

A related ‘portfolio’ approach is the use of neglected and underutilized species (NUS) as rotation crops, cover crops, or diversification options in marginal areas. There is a high nutritional value associated with many NUS, which can enhancethe dietary diversity and broaden the functional space of cropping systems (e.g., drought tolerance, deep rooting, or phenological complementarity), such as [92]. In reality, co-cropping more legume or minor cereal species may add agronomic options for acereal-legume rotation while opening new markets and reducing system-level sensitivity to price or weather disruptions if seed supply, agronomic understanding, and value-chain development are considered [86].

In practice, the use of biodiversity can be achieved in a number of ways, i.e., (i) increasing the diversity of crop species and functional groups in rotations (including cover crops and forage phases where appropriate), (ii) deploying varietal diversity within major crops species (mixtures, multiline varieties or regionally adapted sets of cultivars), and (iii) integrating field-level decisions with landscape features that support beneficial biota (e.g., hedgerows, field margins or semi-natural habitats) in space and time taken from Jackson et al. [85]. These strategies are not alternatives to good agronomy and sound economics; however, they can expand the ecological ‘option set’ available to farmers, and should more explicitly be considered in the design of cereal-legume rotations designed for productivity, input-use efficiency, and resilience to climate. The main ecosystemservices associated with cereal-legume crop rotations and mechanisms are summarized in

Table 4. Summary of ecosystem services provided by cereal-legume crop rotations.

Ecosystem Services	Mechanism	Main Results	References
Soil fertility improvement	Biological nitrogen fixation and diverse residue inputs	Reduced need for synthetic N fertilizers	[29,36]
Soil organic carbon sequestration	Increased biomass inputs and microbial activity	Higher soil carbon storage and improved soil quality
Nutrient cycling	Deep-rooting systems and rhizosphere interactions	Improved nutrient availability and recycling	[28,38]
Pest and disease regulation	Disruption of pathogen life cycles	Lower pest and disease incidence	[49,50]
Weed suppression	Changes in the cropping calendar and competition	Reduced weed seedbank and herbicide use	[51,56]
Climate regulation	Reduced fertilizer use and SOC sequestration	Lower greenhouse gas emissions	[68,76]
Yield stability	Improved soil fertility and system resilience	More stable crop productivity	[67]

.

The economic outcomes summarized in Table 4 suggest that cereal-legume rotations can enhance system profitability primarily through reduced input costs and improved yield stability. However, the magnitude and consistency of these benefits vary across studies, reflecting differences in market conditions, input prices, and management practices. In some cases, reduced fertilizer requirements contribute significantly to economic gains, while in others, profitability is influenced by crop market value and labor demands. This variability highlights that economic performance is strongly context-dependent and should be interpreted alongside agronomic and environmental indicators to provide a comprehensive assessment of system sustainability.

Cereal-legume rotations can improve profitability through lower inputs and stable yields. Economic outcomes are context-dependent.

4. Conclusions

Diverse cereal-legume crop rotations are integral to sustainable intensification as they deliver agronomic productivity alongside measurable gains to ecosystem services. Collectively, evidence gathered across contexts shows that rotation diversification enhances soil physical structure, nutrient cycling, and biological functioning of the system as well as increases the potential to regulate IPDW (integrated pest, disease, and weed) by fostering stable yield over time. These results are in accordance with a functional-diversity approach: species with contrasting rooting depth, residue quality, and phenology exert complementary effects that promote system performance further than the scheme achieved by simplified monocultures.

One of the main reasons for the higher yield in cereals is that they contain legumes, which provide N in a biological form through nitrogen fixation, and 146 also produce “N-credits”, thus helping to reduce emissions of fertilizer sand improve subsequent crop performance. Meanwhile, long-term and multi-site syntheses show that still more diverse rotations can result in small but persistent gains in yield compared to monoculture, and yield gains remain less sensitive to variations in weather. This renders rotations an economically efficient means to enhance the resilience of cereal-based systems. The question of sustainability is also connected to profit and risk. For instance, rotation systems involving legumes generally generate more revenue than those that strictly produce cereals, particularly in the presence of input costs and yield variability.

Cereal-legume rotation can help the environment by lowering the need for synthetic nitrogen fertilizers and, in many cases, allowing soils to store some organic carbon over time. On the other hand, the total footprint relies on how things are managed and the local biophysical parameters. This includes residue management and tillage strategies, evaluating nitrogen savings against potential nitrogen losses. Life cycle studies show that the environmental added value is usually good, but each instance needs to be carefully controlled to avoid trade-offs (such as the risk of N leakage).

However, the overall environmental performance depends strongly on management practices and site-specific conditions. In particular, potential increases in N₂O emissions and nitrate leaching under certain conditions highlight the need for integrated assessment approaches that explicitly account for these trade-offs, rather than assuming universally positive environmental outcomes.

Nevertheless, the benefits of cereal-legume rotations are not universally guaranteed and depend strongly on local environmental conditions, crop selection, and management practices, highlighting the need for context-specific design and implementation.

Lastly, following the lines of this review, cereal-legume rotation systems may be optimized in performance and resilience by purposefully integrating both cereals and legumes across crop biodiversity at several scales: intra-crop genetic diversity (e.g., achieving cultivar mixtures), which decreases disease risk; strategic utilization of crop wild relatives and landraces as reservoirs of adaptive traits; and inclusion of neglected or underutilized species to extend functional options and diversify markets. In general, by properly adapting them to local agroecological constraints and market conditions, and according to the principles of biodiversity, cereal-legume rotations are a solid solution for reconciling production aims with long-term soil health, environmental performance, and agroecosystem resilience.

Based on the synthesis of the reviewed literature, cereal-legume crop rotations should be promoted as a key strategy for sustainable intensification of agroecosystems. To maximize their benefits, several recommendations emerge. Crop rotation design should prioritize the inclusion of legumes with suitable functional traits (e.g., nitrogen fixation capacity, residue quality) adapted to local soil and climatic conditions. Management practices should optimize nitrogen dynamics through synchronization of residue decomposition with crop demand, supported by appropriate residue management and reduced tillage to enhance soil organic carbon while minimizing nitrogen losses. Rotations should be integrated with broader biodiversity-based strategies, including cultivar mixtures and underutilized species, to strengthen system resilience and reduce vulnerability to biotic and climatic stresses. Environmental assessment should adopt a whole-system approach that considers CO₂ and N₂O emissions, carbon sequestration, and nutrient losses, ensuring that trade-offs are properly evaluated.

Finally, economic considerations must be incorporated into rotation design, accounting for input costs, yield stability, and market conditions, while policy and advisory support are essential to facilitate adoption.

5. Challenges and Future Research Priorities

Regardless of the well-documented benefits, the large-scale adoption and optimization of cereal-legume rotations face a series of hurdles. An important aspectis the variability in legume performance and their subsequent N contribution to cereals between different environments and management systems [40,79]. This makes it difficult for farmers to accurately predict N credits and adjust fertilizer dosages accordingly, therefore leading to suboptimal N use [80]. Moreover, there are specific environmental trade-offs. Although legumes reduce the need for synthetic N (which can lower N₂O emissions from fertilizers), the decomposition of legume residues rich in N can also be a source of N₂O, and increased nitrate leaching can occur under certain conditions. Socio–economic factors also play a big part in adoption rates. These include the market demand for specific legumes, the labor costs for legume cultivation and harvesting, the access to appropriate inoculants, as well as the farmers’ knowledge and perception [80,81]. The lack of legume varieties with traits desired by both farmers (e.g., yield stability, pest resistance) and markets (e.g., processing quality) further limits assimilation.

International assessments indicate that biodiversity for food and agriculture is crucial yet diminishing, necessitating integrated actions (policies, institutional frameworks, capacities) for sustainable utilization and conservation [3]. Consequently, IPBES underscores the necessity for revolutionary alterations in critical sectors, particularly agriculture, to prevent biodiversity loss [2]. The Global Strategy for Plant Conservation under the CBD specifically emphasizes recording, protection, restoration, and awareness-raising aims, incorporating plant biodiversity into conservation and governance processes [93].

Finally, documentation of plant diversity remains a dynamic field, with synthetic initiatives (e.g., State of the World’s Plants) providing baseline reports on the number of known species, threats, and knowledge gaps that hinder effective conservation [94]. In this context, the integration of diversification practices in production (such as crop rotation) can act as a “bridge” between productivity and conservation, provided that it is accompanied by landscape management that increases spatial/temporal heterogeneity and limits pressures such as overuse of inputs and loss of semi-natural habitats.

To address said challenges, targeted research is required to fill the existing knowledge gaps. There is a pressing need to better understand and quantify the factors driving the variability in N₂ fixation and the subsequent N availability, from diverse legume species, under different soil and climatic conditions. Mechanistic studies are crucial to figure out the complex interactions of non-N rotational benefits, such as pest and disease suppression and improvements in soil physical properties and P availability. Future research should prioritize the development of regionally adapted legume cultivars that combine high N–fixation capacity with desirable agronomic and market characteristics. Long-term experimental trials are needed to evaluate the cumulative impacts of different cereal-legume rotation designs, especially when they are combined with conservation tillage and residue management, on soil health, carbon sequestration, nutrient cycling, and greenhouse gas balances, including developing accurate regional N₂O emission factors as suggested by Matthews et al. [72]. Furthermore, it is necessary to improve LCA methodologies to better understand the inter-annual dynamics and multifunctional outputs of rotation systems [76]. Finally, socio–economic research that focuses on farmers’ decision-making, effective knowledge transfer, and policy incentives is imperative in order to promote the broader adoption of optimized cereal-legume rotations for sustainable agricultural intensification.