Search Results (127)

Tillage is a major factor influencing soil biological communities, particularly earthworms, which play a key role in soil structure and nutrient cycling. To address soil degradation, less-intensive tillage practices are increasingly being adopted globally and have shown positive effects on earthworm populations when applied consistently over extended periods. However, understanding of the earthworm population dynamics in the period following the implementation of changes in tillage practices remains limited. This three-year field study (2021–2023) investigates earthworm populations during the early transition phase (4–6 years) following the conversion from conventional ploughing to conservation (<8 cm depth, with residue retention) and no-tillage systems in a temperate arable system in central Slovenia. Earthworms were sampled annually in early October from three adjacent fields, each following the same three-year crop rotation (maize—winter cereal + cover crop—soybeans), using a combination of hand-sorting and allyl isothiocyanate (AITC) extraction. Results showed that reduced tillage practices significantly increased both earthworm biomass and abundance compared to conventional ploughing. However, a significant interaction between tillage and year was observed, with a sharp decline in earthworm abundance and mass in 2022, likely driven by a combination of 2022 summer tillage prior to cover crop sowing and extreme drought conditions. Juvenile earthworms were especially affected, with their proportion decreasing from 62% to 34% in ploughed plots and from 63% to 26% in conservation tillage plots. Despite interannual fluctuations, no-till showed the lowest variability in earthworm population. Long-term monitoring is essential to disentangle management and environmental effects and to inform resilient soil management strategies. Full article

Climate change poses one of the greatest challenges of our time, with greenhouse gas (GHG) emissions significantly contributing to global warming. The agriculture, forestry, and land-use (AFOLU) sectors not only emit GHGs but also offer the potential for carbon sequestration, which can mitigate climate change. This study presents a methodological framework for estimating soil organic carbon (SOC) changes based on carbon farming practices in northern Lithuania. Using satellite-derived indicators of cover crops, no-till farming, and residue retention combined with soil and climate data, SOC dynamics were modeled across the Joniškis municipality for the period 2019–2020 using the Rothamsted Carbon Model (RothC) model. The integration of geospatial data and process-based modeling allowed for spatial estimation of SOC change, revealing positive trends ranging from 0.23 to 0.32 t C ha⁻¹ year⁻¹. Higher increases were observed in areas where multiple carbon farming practices overlapped. The proposed workflow demonstrates the potential of combining Earth observation and modeling approaches for regional-scale carbon assessment and provides a basis for future applications in sustainable land management and climate policy support. Full article

Humic acid (HA), a major component of soil organic matter, is a naturally occurring macromolecule formed through the decomposition of plant and microbial residues. Its molecular structure comprises functional groups such as carboxyl, phenolic, hydroxyl, and carbonyl functional groups, which enable HA to interact with soil particles, nutrients, and biological systems. These interactions significantly contribute to soil fertility and overall plant productivity. Functionally, HA enhances soil health by increasing cation exchange capacity, improving water retention, and promoting the formation and stabilization of soil aggregates. In addition to its role in soil conditioning, HA is essential in mitigating plant stress. It achieves this by modulating antioxidant enzyme activity, stabilizing cellular membranes, and alleviating the adverse effects of abiotic stressors such as salinity, drought, and heavy metal toxicity. This review highlights the structural characteristics of HA, its structure-based functions, and the mechanisms involved in plant stress alleviation. Additionally, we explore how HA can be modified through physical, chemical, and biological approaches to enhance its agronomic performance. These modifications are designed to improve HA agronomic efficiency by increasing nutrient bioavailability, reducing environmental losses through minimized leaching and volatilization, and supporting sustainable agricultural practices. Overall, this review underscores the multifaceted roles of HA in promoting plant resilience to environmental stress, highlighting its potential as a key agent in the development of sustainable and eco-friendly crop production systems. Full article

Agricultural waste poses significant environmental, economic, and social challenges globally, with estimates indicating that 10–50% of agricultural products are discarded annually as waste. This review explores strategies for managing agricultural waste to mitigate its adverse impacts and promote sustainable development. Agricultural residues, such as those from sugarcane, rice, and wheat, contribute to pollution when improperly disposed of through burning or burying, contaminating soil, water, and air. However, these residues also represent untapped resources for bioenergy production, composting, mulching, and the creation of value-added products like biochar, bioplastics, single-cell protein and biobased building blocks. The paper highlights various solutions, including integrating agricultural waste into livestock feed formulations to reduce competition for human food crops, producing biofuels like ethanol and biodiesel from lignocellulosic materials, and adopting circular economy practices to upcycle waste into high-value products. Technologies such as anaerobic digestion for biogas production and gasification for synthesis gas offer renewable energy alternatives and ample feedstocks for gas fermentation while addressing waste management issues. Composting and vermicomposting enhance soil fertility, while mulching improves moisture retention and reduces erosion. Moreover, the review emphasizes the importance of policy frameworks, public-private partnerships, and farmer education in promoting effective waste management practices. By implementing these strategies, agricultural waste can be transformed into a resource, contributing to food security, environmental conservation, and economic growth. Full article

Soil organic carbon (SOC) plays a vital role in maintaining soil fertility and ecosystem sustainability, with crop residues serving as a key carbon input. However, how different maize residue components influence SOC stabilization across aggregate sizes and fertility levels remains poorly understood. This study investigated the effects of maize roots, stems, and leaves on SOC dynamics and aggregate-associated carbon under low- and high-fertility Brown Earth soils through a 360-day laboratory incubation. Results revealed that residue incorporation induced an initial increase in SOC, followed by a gradual decline due to microbial mineralization, yet maintained net carbon retention. In low-fertility soil, leaf residues led to the highest SOC content (12.08 g kg⁻¹), whereas root residues were most effective under high-fertility conditions (18.93 g kg⁻¹). Residue addition enhanced macroaggregate (>0.25 mm) formation while reducing microaggregate fractions, with differential patterns of SOC distribution across aggregate sizes. SOC initially accumulated in 0.25–2 mm aggregates but gradually shifted to >2 mm and <0.053 mm fractions over time. Root residues favored stabilization in high-fertility soils via mineral association, while stem and leaf residues promoted aggregate-level carbon protection in low-fertility soils. These findings highlight the interactive roles of residue type and soil fertility in regulating SOC sequestration pathways. Full article

Auricularia auricula (L.) is a widely cultivated edible mushroom, and the resource utilization of its residues offers significant opportunities for sustainable waste management and nutrient recovery. This study investigated the effects of substrate composition on nutrient dynamics and microbial diversity during the aerobic composting of Auricularia auricula (L.) residues. Two treatments were established: composting of Auricularia auricula (L.) residues alone (CR) and composting supplemented with green grass (CRG) over a 49-day period. The results showed that both treatments achieved compost maturity, characterized by a slightly alkaline pH, a germination index (GI) above 80%, and an electrical conductivity below 4 mS/cm. Both composts were odorless, insect-free, and dark brown. Compared to CR, the CRG treatment exhibited higher total organic carbon (TOC) degradation, cumulative total phosphorus (TP) and potassium (TK) levels, as well as enhanced urease, cellulase, and β-glucosidase activities. In contrast, CR retained higher total nitrogen (TN), humic carbon (HEC), fulvic acid carbon (FAC), humic acid carbon (HAC), and a greater humic-to-fulvic acid (HA/FA) ratio. Microbial community analysis revealed diverse bacterial and fungal taxa, with certain species positively correlated with nutrient cycling. Notably, specific substrate compositions promoted beneficial microbial proliferation, essential for efficient composting and nutrient mineralization. These findings not only provide a scientific basis for optimizing composting strategies of mushroom residues but also offer a practical pathway to convert agricultural waste into high-quality organic fertilizers. By enhancing soil fertility, reducing reliance on synthetic fertilizers, and promoting circular bioeconomy practices, this study contributes directly to sustainable agricultural development. CR and CRG treatments, respectively, support either nutrient retention or release, allowing tailored application based on crop demand and soil condition. This study underscores the potential of Auricularia auricula (L.) residues in composting systems, contributing to waste reduction and soil fertility enhancement through tailored substrate management, and offers practical insights into optimizing composting strategies for Auricularia farming by-products. Full article

In Europe, food and agricultural waste amount to millions of tonnes annually. Effective management and valorisation of these residues result in environmental benefits and foster opportunities within the circular economy. Composting has emerged as a sustainable method to convert waste into fertiliser, enhancing soil fertility, water retention, and crop resilience against diseases. However, an adequate compost production process is vital to obtain a functional fertiliser. In this study, a controlled conditions self-produced compost from horticultural waste (C1) was compared against two other commercial composts, one of similar vegetable origin (C2) and another from chicken manure (C3). Physicochemical parameters and nutrient contents in the three compost types were analysed, and phytotoxicity and plant development tests were carried out on Lolium multiflorum Lam. seeds and Pistacia lentiscus L. seedlings. C1 presented fertility and germination parameters similar to C3 and showed the best seedling development. In contrast, C2 showed low levels of fertility, germination, and plant development because of impurities and possible substances inhibiting plant growth, suggesting inadequate compost formation processes. Finally, C3, although it presented germination data similar to C1, produced the worst results in the development of seedlings, probably because of high salinity values and low phosphorus content. Full article

The Mediterranean region faces significant water scarcity, a challenge intensified by climate change, impacting both agricultural productivity and water quality. High sodium levels in irrigation water compromise soil structure, leading to reduced crop yields and economic strain. This study investigates the use of sustainable adsorbents derived from agricultural residues (almond shell, eggshell, and pumice) for the removal of sodium from irrigation water. These materials, widely available in the Mediterranean, support circular economy principles by repurposing biowaste to address agricultural challenges. Adsorption experiments were conducted using real irrigation water, capturing the complexity of its physicochemical properties to evaluate the effectiveness of these biosorbents under practical conditions. A Central Composite Rotational Design (CCRD) was applied to optimize adsorption parameters, focusing on adsorbent concentration, agitation, and contact time. Kinetic studies indicated that sodium adsorption adhered to a pseudo-second order model, suggesting a chemically controlled process. Isotherm analysis, with a strong fit to the Jovanovic model, confirmed a predominantly monomolecular adsorption mechanism across all adsorbents, while the Freundlich model highlighted site heterogeneity. Microscopy and energy-dispersive X-ray spectroscopy (EDX) revealed structural modifications in the adsorbents before and after treatment. The porous internal structure of the almond shell displayed significant sodium retention, while the calcified eggshell surface showed high initial adsorption efficiency but rapid site saturation. Pumice, noted for its extensive porosity, sustained adsorption capacity even with surface deposits formed during treatment. This research demonstrates the potential of biowaste-derived adsorbents for efficient sodium removal from complex aqueous systems, offering a viable solution for sustainable agriculture and improved soil and water management in Mediterranean regions. Full article

Conservation agriculture (CA) is a sustainable land management approach to improve soil quality while mitigating degradation. Although extensive information regarding the effect of CA on soil properties and microbiome is available, complete studies on the cumulative effect on specific interactions between soil parameters, crop productivity, and microbial communities over time are still lacking, mainly in arid regions. Thus, this study aimed to investigate the effects of no-tillage and residue retention over long- and short-term (24 and 3 years, respectively) periods. Six treatments were established in a maize–oat–triticale system from 1995 in a semiarid region: P + H—plow + harrow; H—harrow; MP—multi-plow (short-term); NT—no-tillage; NT33—NT + 33% residue surface cover (long-term); NT66—NT + 66% residue surface cover. Results indicated that CA improved soil quality by increasing soil organic matter (SOM), total carbon, and glomalin; it also enhanced microbial abundance, particularly fungi, and β-galactosidase activity. Nevertheless, conventional tillage practices led to SOM degradation and reduced crop yields. Principal component analysis revealed distinct groupings of treatments based on soil properties and microbial communities. Furthermore, changes could be detected from the short term. These findings highlight the importance of adopting sustainable agricultural practices to maintain soil health and ensure agricultural productivity in semi-arid regions. Full article

Organic fertilizers as partial substitutes for chemical fertilizers improve soil nitrogen (N) retention capacity. However, the relative importance of biotic and abiotic N immobilization at different levels of organic N substitution and the subsequent effects on N utilization in paddy soils are not well elucidated. To address these, a combination of ¹⁵N incubation experiments and pot experiments were conducted to investigate biotic and abiotic N immobilization features and their effects on N fertilizer fate under long-term different fertilization regimes in paddy soils in China. Test soils that had received chemical fertilization (NPK), chemical N was substituted with 30%, 50%, and 70% organic N (70 F + 30 M, 50 F + 50 M, and 30 F + 70 M, respectively), and no fertilization (control) for 36 years. The results revealed that both abiotic and biotic NH₄⁺-N immobilization were enhanced under organic N substitution soils. The highest NH₄⁺-N abiotic and biotic N immobilization was observed under 50 F + 50 M soil, significantly increasing by 195.5% and 51.4%, respectively, compared to the NPK soil. In contrast, only abiotic NO₃⁻-N immobilization increased with rising organic substitution N proportions. N fertilizer utilization efficiency was significantly enhanced in 50 F + 50 M soil (36.7%) compared to the NPK soil (30.3%), which was primarily attributed to the enhanced N pool activity and N immobilization capacity. However, the N fertilizer residue rate was significantly higher in the 30 F + 70 M soil (23.6%) compared to the NPK soil (21.6%), largely attributed to the soil properties improvement. Our results suggest that N immobilization capacity and N fertilizer utilization can be optimized with a 50% organic substitution ratio in our studied soil–crop system. Full article

Fragipans are dense subsurface soil layers that severely restrict root penetration and water movement. The presence of shallow fragipan horizons limits row crop production. We hypothesized that the roots of cover crop might improve soil physiochemical properties and biological activity, facilitating drainage and increasing effective soil depth for greater long-term soil water storage. To evaluate annual ryegrass as one component of a cover crop (CC) mix for promoting the characteristics and distribution of soil water, on-farm studies were conducted at Marion and Springerton in southern Illinois, USA. Soil samples were collected at 15 cm increments to 60 cm (Marion) and 90 cm (Springerton) depths during the fall of 2022. Both sites had low total soil carbon and nitrogen contents and acidic soil pH (≤6.4). A soil water retention curve was fitted using the van Genuchten equation. At Springerton, the CC treatment increased saturated (thetaS) and residual (thetaR) soil water contents above those of the no cover crop (NCC) at the 60–75 cm and 75–90 cm depths. Changes in volumetric soil water content were measured using a multi-depth soil water sensor for the Springerton site during late July to early August of the soybean growing phase of 2022; NCC had higher soil water than CC within the 0–15 cm depth, but CC had higher soil water than NCC at the 30–45 cm depth. These findings indicate that cover crop mix has the potential to improve soil water movement for soils with restrictive subsoil horizon, possibly through reducing the soil hydraulic gradient between the surface and restrictive subsurface soil layers. Full article

The sustainable productivity of rice–wheat cropping systems relies on soil health, and soil health can be positively influenced by treating previous crop residues using conservation tillage practices. The present study examined the impact of three rice residue-management practices under zero-tilled wheat (ZTW) and conventionally tilled wheat (CTW), along with two rice-sowing practices, during rice cultivation on soil functional microbial diversity, physiological profiling, and grain yields of rice and wheat. Anchored residues (ARs) under ZTW exhibited significantly (p ≤ 0.05) high average well color development—31.43% more than CTW with no residue (NR). CTW with residue burning (BUR) showed a 5.42% increase in the Shannon diversity index compared to CTW-NR. Substrate richness was 10.02% higher in CTW-BUR compared to CTW-NR. CTW-BUR demonstrated the highest 17.98% increase in the Shannon evenness index compared to CTW-NR. The direct-seeded rice (DSR) system generally surpassed puddled transplanted rice (PTR) in most indices, except for the Shannon evenness index values. ZTW-AR exhibited the highest utilization of amino acids, carboxylic acids, and phenolic compounds, while CTW-BUR exhibited the highest utilization of carbohydrates and polymers utilization, and ZTW with no-residue (NR) exhibited the highest utilization of amines. Rice and wheat grain yields were highest with full residue in ZTW and lowest in CTW-NR. PTR supported higher rice yields, while DSR was superior for wheat. These findings highlight the favorable role of residue retention with no tillage during wheat cultivation in the maintenance of soil quality and rice–wheat productivity. Full article

Cover crops (CC), pruning residues (PR), and olive mill pomace (OP) are common amendments to enhance soil quality in olive groves; however, there is limited information on the dynamics of carbon (C) and nitrogen (N) during their decomposition under varying conditions. In this laboratory decomposition experiment, we assessed the C and N mineralization of CC, PR, and OP at application rates of 2 and 5 mg C g⁻¹ in soils with varying organic C levels, both with and without the addition of NO₃⁻. The results indicated that C and N mineralization patterns varied significantly between amendments, although the predicted remaining C after one year was similar for CC and PR (46.7–48.9%) and slightly lower for OP (40.0%). Soil organic carbon level did not affect remaining amendment-C. The addition of N accelerated the decomposition rate of labile C by 15% but slowed down that of the recalcitrant C another 13%, with no significant effect on remaining C. Conversely, increasing the C dose led to a 13% overall reduction in amendment-C mineralization across all combinations of factors. CC decomposition released between −8 and 31% of the amendment-N by day 130, while PR and OP showed net N immobilization. Therefore, CC residues contribute to both C sequestration and N availability, while PR and OP residues can improve N retention in the olive groves while also contributing to C sequestration. Full article

This on-farm study was conducted to assess the impact of six prevalent crop management practices adopted by growers in West Texas on various indicators of soil health. This study is a part of a citizen science project, where we collaborated with cotton growers who helped with standardized sample and data collection from 2017 to 2022. This project aimed to identify soil management practices that increase carbon sequestration, enhance biological activities, and improve overall soil health. We monitored soil moisture, soil organic matter (SOM), inorganic nitrogen (NH₄⁺-N and NO₃⁻-N) and other exchangeable nutrients, and soil microbial abundances as obtained via fatty acid methyl ester (FAME) in 85 fields, incorporating different management practices during the cotton growing season. In our study, volumetric moisture content (VWC) was increased by no-till, irrigation, and crop rotation, but the addition of residue decreased VWC. No-till, irrigation, and crop rotation increased SOM, but a cover crop decreased SOM. No-till and residue retention also increased microbial biomass carbon (MBC). Tillage, irrigation, and crop rotation influenced the abundance of the main microbial groups, including bacterial, fungi, and arbuscular mycorrhizal fungi (AMF). Additionally, water content, SOM, and microbial abundances are correlated with clay percentage. Our results indicate that no-till and crop rotation are the two most crucial soil management approaches for sustainable soil health. As such, implementing both no-till and crop rotation in the cropping systems has the most promising potential to increase the soil resilience in dryland cotton production in semiarid regions, thereby helping growers to maintain cotton production. Full article

Wheat (Triticum aestivum, L.) producers have the choice to retain or remove residue from the cropping system following grain harvest. In the U.S. Pacific Northwest and other regions, wheat residue is often sold to increase operational profitability, especially from higher-yielding systems. But there are several benefits to retaining residue, including recycling of mineral nutrients contained therein, though this is understudied. Therefore, the primary objectives of this research were to collect and analyze a large and diverse dataset on wheat residue nutrient uptake (N, P, K, Ca, Mg, S, Fe, Zn, Mn, Cu), develop tools to estimate nutrient amounts in residue, and make economic estimates of the fertilizer replacement value of those nutrients. This was accomplished by conducting replicated variety trials on five classes of wheat across many Pacific Northwest sites over two years, then collecting and analyzing data on wheat residue biomass, residue nutrient concentrations, and grain yield. The results showed that wheat residue contained a significant amount of nutrients, but was particularly concentrated in K. Production environment had the most substantial effect on residue mineral uptake amounts, due to site differences in yield and soil nutrient availability. To enable simple estimation of residue nutrient uptake across a broad range of wheat production levels, two estimation tools are presented herein. Economic analysis showed the substantial monetary value of residual nutrients. For example, in a high-yielding wheat crop (9 Mg ha⁻¹), the average fertilizer replacement value of just residue N, P, K, and S was similar to the entire fertilizer budget to grow the crop (~$211 vs. $205 ha⁻¹), not considering micronutrients in the residue or any nutrients removed through grain harvest. In making residue management decisions, wheat producers should consider the tradeoff between the immediate economic gains of residue sale and the multifaceted benefits of residue retention, including savings on future nutrient costs. Full article