A Review of Common Crop Residue Management Practices in Grain Production

Abstract

Crop residue plays a significant role on soil health, nutrient cycling, and crop yield, making residue management a key consideration in agricultural production. This review aims to synthesize current knowledge on two different aspects of crop residue in grain production systems: common management practices and their effects. A comprehensive literature survey was conducted using the Scopus database, covering worldwide publications from 1990 to 2025. First, this review explores various crop residue management practices, including burning, stubble retention, and different tillage methods (conservation tillage vs. conventional tillage). This section mainly focuses on tillage practices with an emphasis on the environmental, economic, and agronomic consequences of each approach. Then this review paper explores the effects of crop residue on soils and ecosystems, including the role of crop residues in improving soil quality and enhancing soil organic carbon sequestration. The interaction between crop residues and hydrological processes such as water infiltration and runoff is also examined in this section. The relationships between residue management practices and crop growth and yield responses are also critically assessed. This review highlights the shift from conventional, environmentally detrimental practices toward conservation-oriented approaches, especially reduced tillage, no tillage, and residue retention. Key knowledge gaps and research priorities are identified, particularly regarding crop residue effects on deep soil carbon sequestration, hydrology, crop growth and yields, and the lack of practical management guidelines across agroecosystems. This review provides an integrated framework to support crop residue management and guide future research in conservation agriculture.

1. Introduction

During the past few decades, rapid population growth has placed increasing pressure on food production, resulting in significant strain on soil productivity. In addition to agricultural practices, climate changes and human activities also aggravate the soil degradation process, which has become a global issue that seriously threatens the ecological environment and food security [1]. Crop residue, which refers to the remaining plant biomass after harvesting, plays a crucial role in enhancing soil health by supplying nutrients and preventing soil erosion. Crop residue promotes physical, chemical, and biological properties of soil [2], which helps to improve soil quality and productivity, ultimately leading to an increase in crop yields.

Crop residue management is driven primarily by the need to enhance crop yields and ensure sustainable agricultural practices. Farmers often focus on residue management to mitigate potential negative impacts on subsequent crop performance, such as competition for nutrients and water, increased disease risk, and challenges in planting. Properly managing crop residues can improve soil health, increase moisture retention, and promote beneficial microbial activity, all of which contribute to better yields in the subsequent crops. Crop residue management practices can be categorized into 3 types: removal, incorporation, and conservation [3]. In the Midwest, common tillage practices, including conventional tillage, reduced tillage, and no till, play a significant role in how farmers address these residue management concerns. According to USDA National Agricultural Statistics Service [4], 37.96% of crop production land used in the USA utilizes no till, 28.79% utilizes reduced tillage, and 33.24% utilizes conventional tillage. Conventional tillage, often used for its efficiency in weed control, can lead to soil erosion and degradation. In contrast, conservation tillage methods, such as no till and reduced tillage, focus on maintaining crop residues on the soil surface, which can improve soil structure, moisture retention, and organic matter content. The intricacies of tillage in agriculture are complex, with results heavily influenced by field conditions and weather patterns. The management of crop residues should be done in such a way that it benefits the grower without negatively impacting the health and productivity of the soil and the environment. Crop residue management offers numerous benefits and, consequently, has attracted growing research interest. Figure 1 illustrates the trend of publications from 1990 to 2025 based on Scopus data. The Scopus search was conducted on Article titles, Abstracts, and Keywords using the terms “crop residue” and “residue management”, refined by the subject area “Agricultural and Biological Sciences” and publications available in English. The bar chart shows a clear upward trend and a substantial increase in research activity in recent decades. The line graphs represent different research focuses based on additional keyword combinations. Within the research areas of “crop residue” and “residue management”, “Tillage” has consistently remained a prominent topic throughout the study period, and in recent years, topics focused on sustainability, such as “cover crops” and “bioenergy”, have increased in attention.

The aim of this review paper is to bring together research exploring different crop residue management practices, with a primary focus on tillage, and to summarize the effects of crop residue on soil, environment, and crop yield. This review consists of three main sections: (1) an overview of crop residue management practices, including burning, stubble retention, chemical and biological removal, and various tillage approaches; (2) the effects of crop residues on soil and environment, and crop growth and yield; (3) a summary of the current state of knowledge and possible research directions for future studies in crop residue management.

Scopus was used to conduct the literature search, covering research articles published between 1990 and 2025. To comprehensively examine various residue management practices and the effects of crop residues on different aspects, multiple keyword combinations were employed. The core search term, (“crop residue” AND “residue management”), was applied to all searches and combined with additional keywords, including (“soil organic carbon” OR “soil organic matter”), (“crop growth” OR “crop yields”), (“water infiltration” OR “water loss” OR “surface runoff” OR “water retention”), as well as (“tillage”), (“cover crops”), (“bioenergy”), and (“biopreparation”). All results were refined by the subject area “Agricultural and Biological Sciences” and were limited to publications available in English. This synthesis is narrative and not all-inclusive. After title and abstract screening for relevance to crop residue management and its effects, 72 articles were strategically selected for in-depth review. Based on the geographic distribution of these studies, Figure 2 illustrates the contributing countries and the corresponding number of publications, highlighting the global scope of research on crop residues and residue management. This review provides an integrated overview of current knowledge on the effects of crop residues and the implications of different management practices worldwide.

2. Crop Residue Management

Many studies suggest that crop residues left on the grounds of agricultural fields help to protect soil fertility, improve soil quality [5], and increase soil organic carbon sequestration [6]. Crop residues influence soil water movement, runoff, and infiltration while also adding a significant amount of nutrients to the soil for crop production. Managing the quantity, distribution, and orientation of crop residue on the soil surface is known as crop residue management, or CRM. Agricultural producers utilize crop residue management techniques to effectively address the residue from the previous crop year in order to improve the yield of subsequent crops while promoting soil health. Practices such as crop rotation, stubble management, and conservation tillage are used not only to manage crop residues but also to optimize the benefits of conservation agriculture systems. Crop residue management is a crucial component of a conservation agriculture (CA) system, and in situ management is the only way to maximize the benefits of CA. However, in agricultural productivity, crop residue decomposition has both favorable and unfavorable effects. The crop residue affects evaporation, transpiration, rain interception, snow trapping, water infiltration, and runoff. Their management can therefore have significant impacts on the hydrological cycle and surface runoff dynamics. This impact is shaped by farmers’ short-term choices of crops and tillage, long-term regional shifts in climate and cropping systems, and landscape factors such as topography and soil variability [7]. Crop residues also play a crucial role in safeguarding soil from erosion, reducing soil temperatures in warmer climates, diminishing soil evaporation, suppressing weeds, and contributing to the maintenance of soil organic matter and associated aggregate stability [8,9].

Crop residue coverage (CRC) is an important indicator of crop management quality, especially for tillage practices, and hence a key metric for evaluating the job quality of agricultural machinery. Numerous methods have been developed to quantify crop residue, including the line transect method [10], the photographic method [11], and more advanced approaches employing techniques such as remote sensing and machine learning. These advanced crop residue measurement methods can be broadly classified into ground-based, satellite-based, and UAV-based approaches [12].

2.1. Various Crop Residue Management Practices

The residues remaining on the soil following a crop’s harvest can be handled in different ways. While burning crop residues is practiced in some regions to reduce residue amounts and ease the seeding and establishment of subsequent crops, conservation-oriented methods such as tillage, residue retention, and mulching are more widely adopted and recommended for sustainable residue management. Another option involves baling or removing crop residues for external use, such as animal feed, bedding material, or fuel. Residues can also be integrated into the soil in situ through tillage, or they may be wholly or partially preserved on the soil surface as mulch [13]. Other practices, such as burning, stubble retention, cover crops, baling, bioenergy generation, and harrowing, are also in practice. A simplified classification of CRM practices can be seen in Figure 3. In the United States, tillage is the most used crop residue management practice [4]. This sub-section focuses mainly on tillage.

2.1.1. Removal

Burning crop residues has traditionally been used to reduce residue amounts and ease the seeding and establishment of subsequent crops. However, due to environmental concerns, the burning of crop residues has been banned in most developed countries [14]. Although possessing numerous applications and considerable potential to improve crop and livestock production, a considerable portion of crop residues are incinerated, particularly in Asian nations [15].

Alternative practices involve baling or removing crop residues for external use, such as animal feed, bedding material, or fuel. Crop residues are one of the most accessible sources of bioenergy feedstock, showing substantial potential for bioenergy development. In China, the annual net production of crop residues is estimated at 505.5 million tons, corresponding to a bioenergy potential of 253.7 million tons of standard coal equivalent per year, which accounted for 8.27% of the country’s total energy consumption in 2009 [16]. In India, about 686 million tons of gross crop residue biomass is produced annually, of which 234 million tons (34%) are available for bioenergy generation [17]. In Ethiopia, annual gross crop residue production ranges from 69,569 to 105,522 kilo tons, with 42,621–72,194 kilo tons (61–68%) estimated to be recoverable for bioenergy use [18]. However, despite promising potential in bioenergy generation, several challenges limit effective utilization, including biomass losses during harvesting and transportation [19].

2.1.2. Conservation

Environmentally friendly practices are gaining increasing attention. Cover cropping, a long-established practice, has experienced renewed interest due to government policy requirements, changes in the economics of farming systems, and growing public concern for environmental protection and natural resource conservation [20]. Cover crops are defined as a “close-growing crop that provides soil protection, seeding protection, and soil improvement between periods of normal crop production” [21]. Incorporation of cover crops can improve soil structure and hydraulic properties, enhance soil organic carbon and nitrogen sequestration, and create more favorable conditions for soil microbial activity, abundance, and diversity [22,23].

Chemical and biological approaches are also employed for crop residue management. These methods mainly involve the application of chemical or biological products to accelerate the natural decomposition of crop residue. Microbial decomposition involves two major processes: mineralization, the conversion of organic matter to water-soluble inorganic forms, and humification, the transformation of organic matter into structurally refractory substances [24]. A wide range of factors affect the rate and efficiency of crop residue decomposition, including water content, temperature, soil pH, aeration and oxygen supply, nutrient levels (e.g., nitrogen, phosphorus, sulfur), the chemical composition of crop residue (particularly its Carbon:Nitrogen ratio), the microflora of the residue, and the initial biomass [25,26,27,28]. Their effects are not linear and strongly dependent on weather conditions [29]. Nitrogen-containing fertilizers are often applied to accelerate humification [29].

In recent years, biopreparations have gained increasing attention as environmentally friendly alternatives to traditional chemical inputs. Depending on their composition, biopreparations can be categorized as fungal, bacterial, enzymatic, bacterial–fungal, or bacterial–/fungal–enzymatic formulations. Bacteria and fungi are the primary decomposers, which enhance the breakdown of major plant residue components, including cellulose and hemicellulose [24]. Key bacterial genera such as Pseudomonas, Delftia, Rhizobium, and Chryseobacterium have been identified as the dominant contributors during different stages of straw decomposition [30]. Fungal groups such as Cephalotrichum, Sordariales, Coprinus, and Schizothecium also play a significant role, while their activities are strongly influenced by soil salinity and straw type [31]. However, despite the demonstrated benefits of biopreparation in the decomposition of crop residues, the development of biotechnology products still faces challenges such as regulatory problems, ethical and societal considerations, market acceptance, funding and investment, and intellectual property protection [24].

Another option is stubble retention. In agriculture, “stubble” refers to the leftover plant parts, such as stems and stalks, that remain on the soil surface after a crop has been harvested. One of the many intricate problems farmers face is the control of stubble from the previous crop. Grain farmers have historically burned stubble to control weeds and diseases and to lower biomass, which facilitates sowing. This isn’t the recommended choice anymore. There are numerous alternative methods for managing stubble. Keeping the stubble in place prevents soil erosion better than burning or tilling. To maintain crop productivity, it also preserves organic matter and soil moisture. This is especially helpful during dry seasons or in arid regions. While residue-retained systems offer numerous benefits, keeping residues at the surface can also pose notable challenges. For instance, it may lead to obstructions with conventional seeding machinery, especially in regions with high rates of biomass production, such as the humid tropics [32,33,34,35]. Elevated stubble loads have the potential to hinder seed emergence, impacting both plant establishment and crop yield. Additionally, it has been observed that substantial stubble loads might diminish the efficacy of pre-emergence herbicides, as they become bound to the residues, potentially resulting in inadequate weed control [35,36]. In specific environments, like cooler climates, and certain soil types characterized by heavier textures and poor drainage, residue retention may lead to reduced soil temperatures and increased waterlogging, presenting issues for plant germination and growth [37,38].

Combining stubble retention with other practices has also recently received increased attention as a strategy for promoting sustainable agriculture. Dong et al. [39] conducted a 22-year implementation of no tillage combined with stubble retention (NTS) practice and found that NTS treatments increased SOC storage by 64.5% in the 0–30 cm soil layer, while the increases were only 36.1% for conventional tillage, 53.1% for conventional tillage + stubble retention, and 35.5% for no tillage. The NTS treatment also enhanced energy use efficiency by 63.0%, compared with conventional tillage. Similarly, Jha et al. [40] evaluated combinations of two tillage systems [conventional tillage (CT) and no tillage (NT)], two stubble management practices [stubble burned (SB) and stubble retained (SR)], and three nitrogen fertilization rates over a 50-year period at the Hermitage Research Station in Australia. Their results showed that NT increased SOC by an average of 5%, and that conservation agriculture practices integrating stubble retention with judicious nitrogen application are critical for maintaining soil health and enhancing carbon sequestration.

2.1.3. Tillage Practices

Archaeological evidence indicates that approximately 4.5 k years ago, humans were manipulating the soil structure through plowing with hoes and ards [41]. Arable ground was routinely tilled to reduce weeds and improve soil structure and nutrient availability as agriculture became more mechanized. In the midwestern United States, residue cover is strongly related to tillage practices. Crop residues are impacted by tillage in a number of significant ways. The most noticeable is that their location is altered by tillage methods, especially deep tillage. It is possible for nutrients that were formerly at the soil’s surface to now be 15 or 20 cm below the surface. For highly mobile ions like nitrate, this is not very significant; however, for phosphate, it might be more significant, since deep tillage is the only method that some cations can move in the soil at all [42]. Additionally, the nutrients found in organic matter are crucial since thorough tillage should evenly distribute this material throughout the soil, making it more vulnerable to microbial and other creature attacks. This usually indicates that mineralization is aided, though nutrients may occasionally become immobile [42]. Tillage traditionally aids farmers by facilitating optimal seedbeds for planting, minimizing weed competition, and enhancing surface drainage. Additionally, it promotes nutrient availability for plants, expediting the breakdown of organic matter and nitrogen release. Moreover, it incorporates crop residues and livestock manure into the soil, while also aerating and warming it for spring planting. Nonetheless, tillage is known to accelerate soil erosion by exposing topsoil to wind and water, leading to farmland degradation. The main goal of tillage is to control weeds and prepare the seedbed. Tillage helps suppress weeds by (a) burying weed seeds and postponing the growth of perennial weeds; (b) creating a rough surface to prevent weed seed germination; (c) supplying sufficient loose soil to enable efficient row cultivation; (d) maintaining a clean, homogeneous surface for effective herbicide action; and (e) using herbicides as needed.

Tillage practices are broadly classified into two major categories—conservation tillage and conventional tillage. Conservation tillage refers to trying to keep as much residue as possible on the ground, while conventional tillage refers to thorough mixing of residues into the soil. Depending on the intensity or application, both of these types of tillage are subclassified into other tillage types as shown in Figure 3. In terms of tillage practices, tillage systems in the US can be roughly divided among three primary tillage systems: no-till, reduced tillage (excluding no-till), and intensive tillage. In 2017, intensive tillage was used on 28% of US acres for which a tillage system was reported, down from 38% in 2012, ranging from 75% for Rhode Island to 8% for Tennessee [43]. In Brazil and the United States, where no-till land management accounts for 70% and 30%, respectively, of the total farmed land, no-tillage methods are very common. Nevertheless, the majority of these areas are occasionally tilled rather than being constantly cultivated with no tillage. Both global maps of zero tillage and maps of qualitative tillage characteristics like tillage type and depth are absent [44].

Conservation Tillage

One method of managing crop residues is conservation tillage. Conservation tillage can vary from completely disturbing the soil surface by tillage (with a sweep, chisel, or disk, for example) to merely slightly disturbing the surface in preparation for crop seeding (with no tillage). This is all dependent on how much residue is accessible and kept on the surface. Since one of the main objectives of conservation tillage is residue retention, the amount of residues present at crop harvest determines which tillage technique is best in a particular context [45]. In general, the promotion of crop residue coverage is achieved through the adoption of conservation tillage practices, encompassing reduced tillage and no-till (NT) methods. NT involves establishing crops without any preceding tillage. No-till systems, which incorporate NT along with residue retention and crop rotation diversification, are known for saving energy, preventing soil and land degradation, and optimizing water and input utilization [46]. Hence, the NT system represents a resource-conserving technology that boosts input efficiency. Additionally, no-till farming systems can augment soil organic matter, preserve soil moisture, enhance erosion control, and promote agricultural sustainability while minimizing labor requirements.

American Society of Agricultural and Biological Engineers (ASABE) categorizes conservation tillage as any tillage and planting system that maintains over 30% residue cover after planting [3]. Various methods of conservation tillage aim to preserve crop residue, leaves, and roots in close proximity to the soil surface. These methods encompass practices like chiseling, stubble mulching, and no till (NT). Unger et al. [45] has classified conservation tillage into 4 classes—1. No till, 2. Disk tillage, 3. Stubble mulch tillage, and 4. Chisel tillage.

With the introduction of contemporary herbicides in the 1950s, no-till farming gained popularity, particularly in the US [44]. The adoption of no-till practices can significantly reduce soil erosion rates, sometimes achieving over 98% reductions [47]. Furthermore, it can enhance soil quality by increasing organic matter, carbon content, density, water retention, and biological activity, such as earthworm populations. Consequently, no-till methods align with efforts to combat climate change. The integral component of the NT system, the retention of crop residues, serves as a vital source of essential nutrients (such as N, P, potassium (K), and sulfur (S)) through mineralization. Nutrient release from crop residues and native soil organic matter depends on the balance between mineralization and immobilization under different tillage practices, residue management, and soil conditions [48]. Approximately 115 million tons of nitrogen are applied to crops annually by farmers worldwide [49]. Plant residues can alter the inorganic nitrogen content of soil through biotic immobilization–remineralization, abiotic immobilization, soil organic nitrogen mineralization, and organic nitrogen mineralization of plant residues [50]. However, there are tradeoffs involved. While the retention of crop residues in NT systems offers numerous benefits, it also poses challenges such as complicating seeding operations, making plant establishment more challenging, and increasing the prevalence of certain diseases [13]. No till often necessitates the extensive use of chemical herbicides, and some studies suggest increased nutrient losses, potentially due to enhanced soil macropores created by earthworms and other organisms thriving in no-till environments [47]. Findings from a review by [44] suggest that tillage effects remain weakly understood. It was promised that no-tillage methods would greatly reduce SOC carbon emissions. Nevertheless, there is evidence to suggest that the adoption of no-tillage methods following tillage-based management does not significantly raise SOC stocks on most soil types and in most climate regimes. However, there is still debate regarding this part of the no-tillage adaptation. According to their analysis, traditional tillage may actually cause a redistribution of carbon within the soil profile rather than a net loss of soil C. There are conflicting results about the effects of conservation tillage on farmland productivity, for instance. While crop yields are frequently decreased by no-tillage farming, other practices like managing crop residue and crop rotations are crucial for the overall results [44]. Benefits of no-tillage are generally greater in years with limited precipitation [45]. No-tillage often lessens soil erosion, but because the majority of eroded soil carbon is deposited in neighboring ecosystems, consequences on a regional to global scale are questionable [44].

The advantages and drawbacks of no-till (NT) systems vary based on the specific location, contingent upon agro-climatic conditions, farming systems, and socio-economic factors. For instance, the positive impacts of retaining crop residues, such as enhanced aggregation and protection against erosion, compaction, and soil loss, are more pronounced when residues are kept on the surface in regions characterized by a humid tropical climate and a high risk of soil erosion. However, in colder temperate climates, maintaining residues on the surface can lead to lower soil temperatures, potentially adversely affecting crop production. In areas with substantial rainfall, the retention of residues may contribute to excess soil moisture, leading to waterlogging. Consequently, there is a necessity to comprehensively examine the NT system and formulate management strategies that are appropriately tailored to the specific characteristics and requirements of individual locations.

Reduced tillage involves minimizing tillage operations, enhancing the residue cover on the soil. The past several years have seen a significant increase in interest in the adoption of low/reduced tillage techniques. Reducing soil erosion, raising soil productivity, and cutting production costs are all made possible by reduced tillage techniques. Another recommendation for reducing the amount of energy needed in field operations is to utilize reduced tillage techniques [51]. Disk tillage that includes some residues can be employed when there is a comparatively substantial amount of residue present. However, because disking incorporates up to 50-75% of surface residues with each operation, disk tillage should not be employed frequently. Stubble mulch tillage is typically more suitable when full-width tillage is sought, and surface residue quantities are relatively modest. In the US, significant erosion during a major drought in the 1930s led to the development of stubble mulch tillage as a means of controlling wind erosion. In stubble mulch tillage, the majority of crop residues are kept on the soil surface while sweeps or blades undercut the whole soil surface at a depth of 5 to 10 cm to control weeds and create a seedbed for the following crop [45]. Chisel tillage produces retention that is intermediate between disk and stubble mulch tillage [45].

Conventional Tillage

Conventional tillage operations come in a variety of forms and are carried out for various purposes. They can be divided into three categories: subsoiling, primary tillage, and secondary tillage. To provide mole drainage channels or to break up and loosen compacted or dense subsoils, subsoiling may be done sporadically every few years below the usual depth of the other tillage activities. Deep tillage is sometimes carried out by farmers as subsoiling, as it can lead to increased root growth as well as higher water and nutrient uptake [42]. In order to incorporate agricultural leftovers and suppress weeds by burying, primary tillage frequently entails full or partial soil inversion. Primary tillage is performed to loosen soil that has been compacted during prior field operations. Secondary tillage can be carried out to facilitate other field operations, level the surface for precise seed distribution, or create a seedbed by further fragmenting the soil [42]. There are different tillage tool implementations for different purposes. For primary tillage, the most used implements are the moldboard plow, subsoiler, chisel plow, and disk plow [52,53]. For secondary tillage, commonly used implements are cultivator, rotavator, disk harrow, spike-tooth harrow, plank, and roller [52,53]. Figure 4 shows the progressive reduction in surface residue coverage across different stages of conventional tillage. Specialized tillage operations may be carried out for water control objectives in irrigated agriculture or in regions that experience frequent and severe storms [42].

2.2. Costs and Benefits of Tillage and No-Till Practices

Reduced and conservation tillage methods require fewer farm equipment passes in the field, save fuel, and reduce greenhouse gas emissions. In areas where crop cultivation is constrained by water scarcity, the enhanced conservation of soil water commonly observed in residue-retained systems typically results in increased yields, as long as other agronomic challenges associated with the system, such as weed control, pest management, disease prevention, and nutrient management, are effectively addressed [54]. Nevertheless, Naveen-Gupta et al. [55] discovered a decline in the growth and yields of wheat over consecutive seasons in no-till (NT)-based dry-seeded rice–wheat cropping systems, attributing it to variations in seasonal conditions. According to Pittelkow et al. [54], they emphasized that maintaining residue is crucial when adopting no-till (NT), and systems lacking residue retention will result in a decrease in yield, irrespective of the climate.

Tillage practices may cause the soil surface to be uneven. This has two primary effects: it can slow down the commencement of runoff by increasing the surface’s capacity to temporarily store water in depressions, and it can also lower the runoff water’s velocity. There is more time available for water infiltration as a result of both of these impacts [42]. The operation cost of tillage practices is sometimes balanced by the yield improvement. Jalota et al. [56] observed 23–39% more seed cotton yield in the tillage system compared to minimum-tillage practices.

Khoshkharam et al. [57] examined the effects of tillage (disk harrow, tooth harrow, and moldboard) and residue management (100% and 50% burning or retention of barley residues) on maize yield and its components in a barley–maize rotation. They found that there was a significant influence of residue management on germination percentage with 50% residue retention giving the highest germination. Also, with this residue management (50% retention), plant height, fresh forage yield, nitrate of maize, and total protein of plant—all were higher compared to other residue management practices. Comparing the three tillage tools, they observed that the tooth harrow gave the highest germination percentage, plant height, and fresh forage yield compared to the disk harrow and moldboard tillage [57]. These studies are limited, and total cost and benefit calculations of different tillage practices are missing in many studies.

3. Effects of Crop Residues

A major role of crop residues in the agricultural soil ecosystem is to protect soil from wind and water erosion. Crop residues also impact crop yield, costs of crop residue management due to the economics of management practices by means of soil quality changes, carbon sequestration, hydrological processes, crop and biomass productivity, plant emergence, and other direct or indirect mechanisms. This section reviews the impact of crop residues on soils, the environment, and crop yields. Figure 5 presents a schematic summary of the effects of crop residues discussed in this section.

3.1. Impact of Crop Residues on Soil and Environment

3.1.1. Soil Quality

Many aspects have been considered in previous research on soil quality impacts regarding crop residues. The major parameters studied are soil aggregates, soil organic matter (C, N, P, K, lignin, nitrate nitrogen content), pH, earthworm populations, respiration, microbial biomass, volumetric water content, ergosterol concentrations, and soil mechanical and physical properties (such as bulk density, soil cone index, penetration resistance, etc.). About 40% of crop leftovers are made up of organic carbon, which can control soil characteristics and increase soil stability by forming big aggregates [58]. The integrity of soil structure plays a pivotal role in assessing the sustainability of crop production systems and their resilience against erosion.

Within agricultural contexts, various factors including rainfall [59,60], tillage practices, machinery usage, and residue management [5,61,62,63] can alter soil structure and the physical stabilization of soil organic matter (SOM). The retention of crop residue emerges as a significant strategy for enhancing soil structure, facilitated through multiple mechanisms. Firstly, it contributes to soil aggregation by incorporating organic matter into the topsoil. Secondly, it shields soil aggregates from the erosive impact of raindrops. Thirdly, it mitigates soil compaction resulting from raindrop impact [64,65,66,67,68,69]. Assessing the stability of soil aggregates under stress serves as a valuable indicator of soil structural integrity. The preservation of soil aggregates and their stability significantly influences soil porosity, the movement of water, gas, and nutrients within the soil profile, as well as root development [69]. While the addition of residue serves as a crucial factor in stimulating aggregate formation, research indicates that tillage practices may exert a more significant influence. A study conducted in the clay-loam soils of central China’s major rice-producing region demonstrated that continuous no tillage (NT) enhanced surface water-stable aggregates (0.5–2 mm) and particulate organic carbon relative to conventional tillage (CT), independent of residue management in a rice–rape rotation [70]. In this scenario, the absence of soil disturbance allowed for the accumulation of organic matter in the topsoil, facilitating macroaggregate formation even in NT treatments without residue retention [70].

Despite evidence supporting the notion that residue retention enhances the stability of aggregates in the topsoil, contradictory findings have been reported in subsoils under various tillage regimes with or without residue retention. For instance, Bhattacharyya et al. [71] found no discernible differences in macroaggregate proportions within the 5–15 cm layer under different tillage systems, irrespective of surface residue incorporation. Conversely, Li et al. [70] observed reduced macroaggregate proportions in the 5–30 cm layer under NT practices, with or without residue, compared to conventional tillage treatments without residue incorporation. These contrasting findings may be attributed to differences in experimental conditions, including region, climate, soil type, and crop rotation. Bhattacharyya et al. [71] carried out their experiment in India, with a lower annual rainfall (∼1018 mm) and a sandy clay loam soil within a lentil–finger millet production system. In contrast, the study by Li et al. [70] was conducted in China, under a humid mid-subtropical monsoon climate with an annual precipitation ∼1360 mm on a clay loam soil under a rape–rice rotation. Without controlled comparative experiments, it remains difficult to draw definitive conclusions regarding the underlying causes of these inconsistencies. Mulching of crop residues also contributes to soil aggregation through three main mechanisms: physical, chemical, and biological. Physically, the mulch serves as insulation for the soil surface, shields it from the impact of raindrops, and regulates surface soil cycles of freezing-thawing and wetting–drying [72]. Chemically, it releases substances like polysaccharides, humic compounds, and organic mucilage. These compounds act as binders, enveloping and adhering to primary and secondary soil particles to form stable aggregates. Biologically, mulching stimulates the activity of microorganisms such as earthworms and microorganisms like fungi [72]. This biological activity aids in the creation and reinforcement of soil aggregates.

Karlen et al. [5] evaluated several soil quality indicators for 10 years in a no-till corn to determine the effects of manually removing, doubling, or maintaining crop residues. Effects of crop residue management treatments on the 0–600 mm upper soil profile soil quality were evaluated by computing a soil quality index based on four soil functions: (1) accommodating water entry, (2) retaining and supplying water to plants, (3) resisting degradation, and (4) supporting plant growth [5]. Samples were collected from Rozetta and Palsgrove silt loam soils to measure soil aggregate characteristics, penetration resistance, bulk density, earthworm populations, respiration, microbial biomass, volumetric water content, ergosterol concentrations, and several soil test parameters (pH, P, K, Ca, Mg, Total-N, Total-C, NH4-N, and NO3-N). Using their method of soil quality index calculation, they obtained the soil quality ratings of 0.45, 0.68, and 0.86 for the removal, normal, and double residue no-tillage treatments, suggesting the improved soil quality with retained or added crop residue [5]. They found that the soil aggregates from double residue treatments were more stable in water than those from normal or removal treatments. Normal and double residue treatments had higher Total-C concentration and higher levels of microbial activity [5]. For no-till treatment in removal scenarios, the surface cover was 9%, for residue scenarios it was 57%, and for the double scenario it was 83%. Plots receiving normal or double amounts of crop residue had significantly higher levels of ergosterol [5]. Soil pH, P, K, Ca, and Mg concentrations were not statistically significant among the three treatments [5]. Bierke et al. [73] investigated the immediate and prolonged impacts of crop residue management on soil organic matter (SOM) within paddy soils across two experimental locations in China and one in the Philippines. The study assessed parameters such as organic carbon (C), total nitrogen (N), and lignin composition. Findings indicated no significant alterations in organic C, total N, and total lignin-derived phenols following the integration of crop residue in Nanjing and Los Baños. Nevertheless, in plots where residue was incorporated, organic C levels rose by 41%, while in plots where residue was removed by taking the straw out of the field, the increase was measured at 16%.

Donk et al. [74] studied effects of crop residue on soil moisture, soil health, and crop productivity, especially when there’s not enough irrigation water available. The main goals were to understand how removing leftover parts of corn and soybean plants affects various aspects of water balance, like soil moisture, evaporation, and transpiration, and soil characteristics such as pH levels, nitrate nitrogen content, organic matter, phosphorus and potassium levels, and soil density. In this experiment, residue was artificially removed from the plots without any tillage. After the end of this 4-year study, soil samples were collected from each plot to a depth of 20 cm and analyzed for soil chemical and physical properties. Significantly smaller soil organic matter content and soil residue nitrate, and significantly greater soil pH were observed in the bare-soil plots compared to the residue-covered plots. The soil with residue covering retained about 90 mm more water within the upper 1.83 m compared to the soil without residue near the end of the 2009 growing season. Although the effects over the four-year period were minimal and likely not enough to harm crop yields, there were measurable and statistically significant impacts on soil quality. These studies suggest that higher crop residues on the agricultural fields improve the overall soil quality, especially in the top soil layer; however, there are some contradicting findings when it comes to subsoil layers of 5–25 cm.

3.1.2. Soil Organic Carbon Sequestration

Agricultural soils, after long-term cultivation and continuous disturbance from conventional tillage, have lost a substantial portion of their native carbon stocks. Crop residues represent one of the most readily available biomass sources for increasing soil organic matter inputs. Residue retention, particularly under no-tillage systems, helps reduce carbon losses through soil erosion and CO₂ emissions. Therefore, understanding the effects of crop residue on soil organic carbon sequestration is essential for sustaining long-term soil productivity and has attracted considerable research attention.

In Zimbabwe, Chivenge et al. [75] found increased soil organic carbon (SOC) levels in sandy soils treated with mulch ripping and residue preservation, in contrast to clean ripping where residue was removed. They attributed this difference to the retention of residue. The type of soil (sandy soil with more coarse fractions) seemed to influence these results, as no notable discrepancies in SOC were detected in red clay soils subjected to the same experiment. Salinas-García et al. [76] conducted a six-year experiment in two distinct regions of Mexico, namely Apatzingán and Casas Blancas, to investigate organic carbon (SOC) sequestration in rain-fed maize production. They observed that under all four conservation tillage treatments, including no tillage (NT) with varying percentages of residue retention (100%, 66%, and 33%), as well as minimum tillage, SOC content was notably higher compared to conventional tillage methods such as disking and disk plowing. In Casas Blancas, SOC content increased by 46%, while in Apatzingán, it increased by 39% under these conservation tillage treatments with residue retention. Leharwan et al. [77] observed that keeping leftover crop materials on the soil’s surface led to a greater amount of soil organic carbon (SOC) compared to the practice of removing residues from the field. Koga and Tsuji [78] explored how residue management and manure application impact soil characteristics across a 4-year crop rotation. They observed that tillage practices didn’t significantly influence total carbon sequestration, but management of carbon input had notable positive effects.

However, a meta-analysis conducted by Govaerts et al. [79] on soil carbon case studies yielded inconclusive results. Among 78 cases examined, 7 showed lower soil carbon stocks under zero tillage compared to conventional tillage, 40 showed higher stocks, and 31 showed no significant difference. These cases included experiments from diverse regions across seven countries, including Australia, Brazil, Switzerland, and the USA. The variability in results indicates that the impact of agricultural management practices on SOC storage may vary under different climatic conditions, which affect the plant and soil processes that control soil organic matter dynamics. For instance, in cooler and more humid climates, decomposition rates of buried crop residues are reduced, which can limit the potential of zero-tillage systems to enhance SOC storage. After zero tillage, residues remain on the soil surface rather than being incorporated, potentially leading to lower carbon stabilization in cool, moist environments and, in some cases, a net loss of SOC. Despite several studies reporting increased SOC content under no-tillage with residue retention, this practice leads to carbon accumulation near the soil surface, while tillage influences the distribution of SOC throughout the soil profile by incorporating residues into deeper layers [67,79,80,81,82,83,84]. To achieve a more precise evaluation of how residue management practices affect soil organic carbon (SOC), it is advised to collect samples from the entire depth of the plow, as suggested by VandenBygaart and Angers [85]. This approach helps avoid potential bias toward no-till practices, which often involve residue retention, that may occur when only shallow sampling is conducted [80].

3.1.3. Hydrological Processes

Total porosity, soil water retention, and plant available water are some major hydraulic properties/hydrological processes associated with soil. The presence of crop residue within the seed row significantly impacts soil macro-porosity, leading to enhanced soil aeration and temperature, consequently influencing seed germination and emergence [86]. In a study conducted in Ohio by Blanco-Canqui and Lal [87], there was no effective changes in total soil porosity with or without residue removal (for biofuel) from the field for silt loam with a 2% slope. But for silt loam at 10% slope and clay loam at less than 1% slope, the total soil porosity decreased dramatically with residue removal [87]. Similar trends were observed for plant available water and water retention.

The major impact of residue management on hydrological processes is nutrient runoff by eroded soil and by leaching from runoff water, as it poses environmental and economic challenges to agriculture. As soon as runoff water carries this precious, nutrient-rich soil off the farm, it will pollute drinking and recreational water sources, fill drainage ditches and dams with sediments that cause localized flooding, and otherwise cause problems for society as a whole. Having enough amount of crop residue on the field can help prevent these challenges. While a higher residue level, larger biomass, or longer growing season is preferred for reducing rainfall runoff, it can increase unfavorable snowmelt runoff. This situation is similar for conservation tillage, where the practice can be beneficial for meeting crop water demands but increases runoff from snowmelt [7].

3.2. Effect of Crop Residues on Crop Growth and Yield

Crop residue management strategies that retain greater amounts of residue are generally favorable for enhancing soil health and quality; however, from a productivity standpoint, excessive residue may adversely affect agricultural productivity by causing nutrient imbalances and complicating planting operations. This section explores the influence of crop residue on both crop growth and the yield impact of residue management practices.

3.2.1. Influence on Crop Growth

Crop growth can be evaluated using several metrics, including germination percentage, plant height, and stem diameter. Soil moisture, soil temperature, and the thickness of surface residue cover can affect seedling emergence, while nutrient availability influences plant height and stem diameter [57]. Crop residue management can modify soil properties and alter the distribution of surface residues, thereby affecting crop growth and development.

A thick layer of crop residue cover can hinder crop emergence, especially in temperate regions characterized by cool and moist spring conditions. Blanco-Canqui et al. [72] observed that compared to soils lacking residue cover, corn emergence was postponed by 3 days in silt loam soils with 100% residue cover, and by 2 days in those with 75% cover. Similarly, on clay loam soil, corn emergence was delayed by 3 days with 75% residue cover. This delay in seedling emergence directly impacts seedling height. Plants emerging early in unmulched soils often exhibit greater height compared to those emerging later in mulched soils.

3.2.2. Relationship Between Residue Management and Yield

The relationship between residue management and crop yield is closely linked to changes in soil physical, chemical, and biological properties. Different residue management practices can influence soil structure, soil moisture, and nutrient cycling. Hence, proper residue management is essential for enhancing soil fertility and sustaining soil quality, which ultimately affects crop yield.

Gao et al. [88] investigated the influence of various residue management approaches on maize root attributes and crop yield. Their study revealed that plots where crop residues were pulverized and reintegrated into the field exhibited elevated maize root dry weights (an increase of 18.5%), increased root length density (a rise of 13.7%), heightened root surface area density (an increase of 29.4%), and higher yields (an increase of 15.1%) compared to plots where the residues were removed. In a study conducted in Brazil, Satiro et al. [89] assessed and developed a model predicting the effects of straw removal on sugarcane yield. Their findings indicated that, in the short term, straw removal led to a reduction in soil carbon in the surface layer (0.05 m) but did not result in decreased yield. Similarly, Ulmer et al. [90] reported that removing residues did not influence the subsequent yields of corn, soybean (Glycine max), or dry bean (Phaseolus vulgaris L.). Koga and Tsuji [78] explored how residue management and manure application impact crop yields across a 4-year crop rotation. They compared reduced tillage (RT), which involves no deep plowing and only a single shallow harrowing for seedbed preparation, with conventional deep moldboard plow tillage (CT). The combination of RT, residue return, and annual manure application (20 Mg ha⁻¹ each year) notably increased yields of spring wheat and potatoes. However, tillage practices didn’t affect the yields of soybeans and sugar beets.

Judice et al. [91] conducted research to assess the lasting impact of burning and mechanical elimination of sugarcane crop residue on both weed management and the growth and yield of sugarcane. They found a decrease in sugarcane yield by 7.9% when residue remained on the top of the row, as opposed to when it was either burned or mechanically removed. The average sugar yield across various locations and tillage methods was similar for both burning and mechanical residue removal treatments, and it was on average 8.6% higher compared to when residue was left untouched. Hence, they suggested that sugarcane residue should be removed from the row top as soon as after harvest to maximize the yield of the ratoon crop. Beri et al. [92] studied nitrogen and phosphorus transformations as affected by crop residue management practices over a 15-year field experiment and their influence on crop yield. Their study indicated that residue burning and residue removal resulted in greater grain yields compared to residue incorporation for both rice and wheat. The following wheat and maize harvests had far higher grain yields when the residue management treatments ended after 13 years in the areas where the crop residue had been absorbed, as opposed to burned or removed. When fertilizer nitrogen was absent, this effect was more noticeable than when it was 45 and 90 kg N/ha [92]. Karlen et al. [5] observed an average corn grain yield of 8.1, 8.4, and 8.0 Mg ha⁻¹ for removal, normal, and double residue treatments. They also observed that the largest yield difference was contributed to the seasonal difference in the amount of rainfall. In cases of lower average rainfall, the double treatment had higher yield than removal or normal treatment, but in most cases either removal or the normal treatment had higher yield, although the difference is not huge [5]. A reduced yield was reported with with conventional tillage compared to conservation tillage by Leharwan et al. [77] where they studied the effect of tillage and crop residue practices on yield attributes of wheat in India and found that the wheat yield increased from an average value of 43.6 (q ha⁻¹) in conventional tillage (CT) to 52.9 (q ha⁻¹) in zero tillage (ZT). Similar to findings in corn and wheat [5,77], but contrary to results in sugarcane [91], a study conducted by Donk et al. [74] reported higher soybean yields with residue cover (4.5 Mg ha⁻¹) than without residue (3.9 Mg ha⁻¹). Based on two crop production models, it is estimated that between 74 and 91 mm of irrigation water would have been needed to produce this extra 0.6 Mg ha⁻¹. In 2010, the average soybean yield was 3.8 Mg ha⁻¹ in residue-covered plots, compared to 3.3 Mg ha⁻¹ in bare-soil plots. Between 64 and 79 mm of irrigation water would have been required to produce this additional 0.5 Mg ha⁻¹. The contradictory results may be attributed to differences in crop-specific transpiration requirements during the vegetative growth stage. Residue retention typically increases soil moisture and lowers soil temperature early in the growing season, which can reduce plant transpiration rates. For soybeans, greater transpiration during vegetative growth does not necessarily translate into higher grain yield at harvest, as yield formation is more sensitive to conditions during the reproductive stage. In contrast, sugarcane yield is closely linked to cumulative biomass production over its extended growth cycle.

Mirzaei et al. [93] also observed a 6% increase in wheat grain yield when 100% residue was applied as compared to when no residue was applied on their study on preliminary effects of crop residue management on soil quality and crop production. They investigated the effects of crop residue introduction at the rates of 100%, 75%, 50%, 25%, and 0% on soil properties as well and found that the application of plant residue resulted in increased SOC, available nutrients, and improved soil physical properties [93]. These research suggest mixed results with higher yield in conventional tillage systems in some areas, while higher yield in conservation or no-tillage systems in other areas, mostly due to different weather conditions and irrigation requirements.

4. Discussion

The review on crop residue management shows that various practices have been developed to improve management efficiency. Environmental concerns have led to restrictions on residue burning in many regions, while some environmentally friendly practices, such as biopreparations to accelerate crop residue decomposition, have gained popularity. However, it also faces some challenges related to regulatory problems, ethical and societal considerations, and market acceptance, limiting its widespread adoption. Among all different crop residue management practices, tillage continues to be one of the most widely adopted approaches for crop residue management. The past several years have seen a significant increase in interest in the adoption of low tillage techniques. Reducing soil erosion, raising soil productivity, and cutting production costs are all made possible by reduced tillage techniques. However, comprehensive evaluations of the costs and benefits associated with different tillage practices remain lacking in many existing studies.

The review on the effects of crop residue suggests that major research on crop residue effect has been centered around soil quality specifically on soil organic matter and soil aggregates, while other indicators-such as pH, earthworm populations, respiration, microbial biomass, volumetric water content, egrosterol concentration, and soil mechanical and physical properties (bulk density, soil cone index, penetration resistance, etc.)—often show limited or statistically insignificant responses to crop residue management. The studies indicate that increased crop residue cover typically enhances soil quality, especially in the topsoil, while results for subsoil layers at depths of 5–25 cm remain inconsistent. This vertical variability indicates that residue impacts may be depth-dependent, yet few studies have systematically examined subsoil dynamics. The limited focus on subsoil processes restricts a comprehensive understanding of residue management effects on overall soil structure. Studies on the effects of crop residues on soil organic carbon (SOC) sequestration also emphasize the significant role of climatic conditions. In cooler and more humid environments, no-till practices may sometimes even lead to a decline in SOC levels. Regarding the effects of crop residue on crop yields of subsequent crops, some studies have found that crop residue helps in yield increases, others have found that yield decreases, and some studies have found no significant changes in yield. These contradictory results suggest that the specific effects depend on diverse factors, including crop type and the weather and climate of the studied region. However, many studies rely on simple comparative designs, which are not capable of isolating these interacting variables. As a result, the mechanisms underlying yield responses are not fully understood.

Despite the fact that multiple studies exist on the effects of residues and residue management, standard guidelines on when, where, and how much residues should be removed have not been made yet. This highlights a gap between empirical findings and practical implementation, limiting the translation of research outcomes into actionable management strategies.

Table 1. Summary of tillage practices and their effects.

Tillage Practice	Effects
	Soil Quality	Soil Organic Carbon Sequestration	Hydrological Process	Crop Growth	Yield
No till	[5,48,59,61,70,71,72,77,81,82,83,93]	[39,40,48,61,70,71,76,77,81,82,83,84,93]	[59,60,86,93]	[55,72]	[55,72,77,91,93]
Reduced till	[48,64,65,66,77]	[48,64,65,66,75,76,77,78,84]	[60]	[57]	[56,57,77,78,91]
Conventional till	[48,65,70,71,77,81,83,93]	[39,40,48,65,70,71,76,77,78,81,83,93]	[93]	[55,60]	[55,56,77,78,93]

summarizes the research findings from the above literature work regarding the effects of certain tillage practices. From this table, it can be observed that most research focuses on the tillage practices’ effects on soil quality and soil organic carbon sequestration. These two aspects are closely linked, because to analyze the effects on soil organic carbon sequestration, soil organic carbon and relevant properties need to be examined, which is a part of soil quality. However, there has been less research on hydrological processes, making it a potential area of focus for future studies. Soil erosion is related to the hydrological process. Understanding more about the hydrological process helps with soil conservation by applying appropriate tillage practices. Some studies have learned the effects of tillage practices on yield, but most of them simply compared the yields of different tillage practices without exploring the underlying mechanisms. For crop growth, there was limited work focusing on tillage effects on germination percentage and plant height. This is also another possible concentration for future study since the crop growth is highly correlated with yield.

Overall, this review highlights several potential directions for future research:

• The effects of crop residue on SOC sequestration in deeper soil layers. The majority of existing studies concentrate on SOC dynamics in the topsoil, whereas findings for subsoil layers remain inconsistent and insufficiently explained. Research on how crop residue influences subsoil carbon storage and the underlying mechanisms may be beneficial for long-term sustainability.
• The effects of crop residue on hydrological processes. Despite abundant research on crop residue’s effects on soil quality and soil organic carbon sequestration, hydrological processes have received comparatively less attention. Since hydrological processes directly influence soil erosion and water conservation, insufficient investigation in this area limits the development of optimized tillage strategies.
• The dynamics of crop residue–yield interaction. Contradictory results of existing studies demonstrate a limited understanding of how crop residue could affect crop productivity. Future research should conduct dedicated experiments to control multiple factors, considering crop type, residue rate, soil types, and climatic conditions.
• Approaches to translate research findings to practical management practices. Although plenty of studies have been conducted on crop residue and residue management, comprehensive cost–benefit analyses of different tillage and residue management practices are still limited, and standardized guidelines regarding when, where, and how much residue should be removed or retained have yet to be established.

5. Conclusions

This review article summarizes existing research on crop residue management practices and the effects of crop residue, covering statistics and studies from diverse regions worldwide. Over the past decades, research interests have shifted toward more environmentally friendly approaches, including the transition from residue burning to residue retention, from chemical inputs to biological products, and from conventional tillage to conservation tillage. Crop residue management is a critical component of sustainable agricultural practices, which shows great influence on soil health, crop productivity, and environmental conservation. Numerous studies have documented the impacts of crop residues, which are highly dependent on other factors such as climate, crop rotation, residue type, and soil composition, to mention a few. Although conservation and reduced-tillage practices are widely promoted for their environmental benefits, some studies have reported reductions in crop yields for fields that applied conservation tillage, highlighting the complexity of interactions among crop residues, soil properties, and crop growth. Consequently, the choice between tillage and no-till practices, as well as other residue management strategies, must be made with careful consideration of the specific agricultural context, economic viability, and environmental objectives. This review also identifies important opportunities for future research. In particular, greater attention is needed to understand how different tillage and residue management practices influence soil organic carbon sequestration in deeper soil layers, hydrological processes, and crop growth parameters, and how these factors influence crop yields across diverse agroecosystems. Additionally, there is also a critical need to translate research findings to practical guidelines for residue management based on agronomic, environmental, and economic assessments. Addressing these knowledge gaps will be essential for developing more effective and sustainable crop residue management strategies.