Tillage and residue management strategies enhance crop yields, soil health, and profitability in the rice-wheat system of Nepal’s Western Terai

Macro-and/or microplastics as an emerging threat effect crop growth and soil health

Substitution of chemical fertilizers with organic fertilizers is often considered a sustainable approach that can support soil health and promote crop yield. Arbuscular mycorrhizal (AM) fungi are crucial for maintaining ecosystem multifunctionality; however, their beneficial functions are often influenced by fertilization. Up to now, the global impacts of organic fertilizers on AM fungal communities and mycorrhizal benefits on crop yield and soil health remain unclear. Here we conducted a global meta‐analysis to address these knowledge gaps regarding the impact of organic fertilizers application on the growth of AM fungi, and whether AM fungi could increase crop yield and improve soil health under the condition of substitution of organic fertilizers for chemical fertilizers. Based on global meta‐analysis, we found that organic fertilizers application can increase AM fungal biomass and richness by inhibiting soil acidification and increasing soil organic carbon content. Moreover, the benefits of replacing chemical fertilizers with organic fertilizers for AM fungal communities depend on the agricultural management and climatic conditions. Full substitution of chemical fertilizers with organic fertilizers significantly enhanced AM fungal spore density (SD), phospholipid fatty acids and diversity compared to partial substitution. Monoculture systems outperformed crop rotation in promoting root colonization, SD and neutral lipid fatty acids. In hot and rainy regions, replacing chemical fertilizers with organic fertilizers significantly promoted AM fungal SD and richness. It is worth noting that AM fungal richness is positively related to crop yield and soil health, further emphasizing the importance of AM fungi in promoting plant growth and maintaining soil health under organic fertilizer application conditions. These findings emphasize the unique role of enriching AM fungal communities through organic fertilizers in supporting plant productivity and soil health. Our research underscores the significance of AM fungi as a nature‐based pathway for enhancing ecosystem multifunctionality and boosting nutrient utilization efficiency within agricultural ecosystems. Read the free Plain Language Summary for this article on the Journal blog.

Globally, declining soil quality due to soil degradation is of great concern, and directly affects crop production, soil health and sustainability of natural resources. In conventional farming practices, the loss of fertile topsoil via runoff and erosion from arable land is a big concern. In addition, changes in land use and management practices result in loss of soil organic carbon (SOC) stock by −10–59%. The change from conventional till (CT) with residue burning/removal to no-till (NT) farming with residue retention/conservation agriculture (CA) practices have been recognised as important soil management practices for sustaining soil health and reversing land degradation. Worldwide, NT/CA practices are now being adopted on about 180 million ha (i.e. ∼14% of arable land). CA practices promote soil health by increasing organic carbon, and soil aggregation, thus improving infiltration and minimising erosion losses. In addition, CA has the potential to increase SOC sequestration, reduce greenhouse gas (GHG) emissions and help to mitigate global climate change. Among sustainable food production systems, CA is often advocated with a view to increase food production while conserving natural resources and SOC. This special issue ‘No-till farming: prospects, challenges – productivity, soil health, and ecosystem services’ addresses and critically reviews these important issues and aims to foster awareness of NT farming. The collection of 15 papers lucidly covers various facets of NT farming. A summary and salient findings of these papers are provided in this Editorial. NT farming is a promising practice, which not only improves soil physical, chemical and biological health but also enhances carbon sequestration, crop productivity and mitigates GHG emissions through appropriate crop residue and nutrient management strategies. The adage says ‘one size won’t fit all’ or ‘a single recipe will not solve all problem/challenges’, so we need to adopt site-specific NT systems for higher benefits and productivity and sustaining soil health.

Intercropping, the practice of growing two or more crops in the same area, has been widely recognized for its ability to enhance soil health, improve crop yield, and promote sustainability in agriculture. This research explores the impact of intercropping on soybean (Glycine max) growth and seed yield, focusing on the role of soil health from a homoeopathic perspective. The primary objective of this study is to evaluate how different intercropping systems, incorporating specific companion crops, affect soybean growth traits and yield, with an emphasis on soil fertility and ecological balance. Soybean is an essential crop globally, valued for its high protein content and ability to fix nitrogen in the soil. However, conventional farming practices, particularly monocropping, often lead to soil degradation and lower yields. In contrast, intercropping can improve soil structure, enhance nutrient cycling, and reduce the need for synthetic fertilizers and pesticides, contributing to more sustainable agricultural systems. This research examines various intercropping systems and their influence on soybean growth, with a particular focus on soil health as a crucial factor for boosting productivity. Soybean is an essential crop globally, valued for its high protein content and ability to fix nitrogen in the soil. However, conventional farming practices, particularly monocropping, often lead to soil degradation and lower yields. In contrast, intercropping can improve soil structure, enhance nutrient cycling, and reduce the need for synthetic fertilizers and pesticides, contributing to more sustainable agricultural systems. This research examines various intercropping systems and their influence on soybean growth, focusing on soil health as a crucial factor for boosting productivity. The homoeopathic principles applied to soil management explore the idea that optimizing the soil ecosystem can lead to healthier crops with higher resilience. Field trials and laboratory experiments were conducted to observe the effects of intercropping on soybean’s growth traits, including plant height, biomass, and seed yield. The results show that intercropping systems improve soybean yield by promoting better soil health, enhancing nutrient availability, and reducing pest pressure. Furthermore, these findings align with sustainable farming practices that aim to balance ecological health with agricultural productivity. This paper underscores the importance of intercropping as a sustainable solution to improve soybean productivity, contributing to long-term soil health and farm sustainability. By incorporating homoeopathic principles into soil management, this research offers new insights into how intercropping systems can support ecological balance and enhance crop yield in modern agricultural systems. Soybean (Glycine max) is one of the most important leguminous crops worldwide, known for its high nutritional value and significant role in crop rotation and soil fertility management. Traditional farming practices have often been associated with monocropping, leading to soil depletion and reduced agricultural productivity over time. In contrast, intercropping has emerged as a viable solution to mitigate these challenges, particularly by improving soil health and enhancing yield through biodiversity. The concept of intercropping involves the simultaneous cultivation of two or more crops in the same space, and it has been suggested that this practice can lead to complementary growth patterns and higher productivity.

One of the critical challenges in agriculture is enhancing yield without compromising its foundation, a healthy environment and, particularly, soils. Hence, there is an urgent need to identify management practices that simultaneously support soil health and production and help achieve environmentally sound production systems. To investigate how management influences production and soil health under realistic agronomic conditions, we conducted an on‐farm study involving 60 wheat fields managed conventionally, under no‐till or organically. We assessed 68 variables defining management, production and soil health properties. We examined how management systems and individual practices describing crop diversification, fertiliser inputs, agrochemical use and soil disturbance influenced production—quantity and quality—and soil health focusing on aspects ranging from soil organic matter over soil structure to microbial abundance and diversity. Our on‐farm comparison showed marked differences between soil health and production in the current system: organic management resulted in the best overall soil health (+47%) but the most significant yield gap (−34%) compared to conventional management. No‐till systems were generally intermediate, exhibiting a smaller yield gap (−17%) and only a marginally improved level of soil health (+5%) compared to conventional management. Yet, the overlap between management systems in production and soil health properties was considerably large. Our results further highlight the importance of soil health for productivity by revealing positive associations between crop yield and soil health properties, particularly under conventional management, whereas factors such as weed pressure were more dominant in organic systems. None of the three systems showed advantages in supporting production‐soil health‐based multifunctionality. In contrast, a cross‐system analysis suggests that multifunctional agroecosystems could be achieved through a combination of crop diversification and organic amendments with effective crop protection. Synthesis and applications: Our on‐farm study implies that current trade‐offs in managing production and soil health could be overcome through more balanced systems incorporating conventional and alternative approaches. Such multifunctionality supporting systems could unlock synergies between vital ecosystem services and help achieve productive yet environmentally sound agriculture supported by healthy soils.

The world population is increasing to the 7 billion marks and until the mid-2030s, the planet can expect to shoulder annual additions of 50–70 million more peoples leading to an issue of poverty, food security and access to fertile and healthy soils. Crop productivity, soil fertility and health are continuously declining due to removal of essential plant nutrients from the soils under cereals-based system in the current changing climate scenario. Cereals (wheat, maize, rice etc.) crops provide humankind with more nourishment than any other food class and nearly half of the total caloric requirement globally. As cereals are exhaustive (decline soil fertility) crops and therefore their continuous growth without balanced nutrients management decline crop productivity, soil fertility and soil health. Sustainable soil management (SSM) practices not only increase crop productivity but also improve soil fertility, health and sustainability. Widespread adoption of SSM practices generates multiple socio-economic benefits for both smallholder farmers and large-scale agricultural producers. We concluded from the review that integrated nutrients management (INM) improve soil health for sustained crop productivity in cereal based system. The concept of INM is the combined application of chemical fertilizers [nitrogenous fertilizers (urea, ammonium sulphate etc.), phosphatic fertilizers (Di-ammonium phosphate, single super phosphate etc.), and potash fertilizers (sulphate of potash, muriate of potash etc.) zinc etc.) plus incorporation of different organic matter sources [(1) animal-based sources (poultry manure, cattle manure, sheep manure, goat manure etc.) and (2) plant-based sources e.g. vegetables residues (onion, garlic etc.), cereals residues (wheat, maize, rice etc.), legumes/pulses residues (chickpea, faba bean, mungbean, cowpea etc.) and tree residues (peach, pepper mulberry etc.)] into the soil along with application of biofertilizers (beneficial microbes) improve soil fertility and health, crop growth and yield, growers income and sustainability. We concluded that INM practices which are one of the best SSM practices are recommended in exhaustive cereal-based system to decrease soil degradation due to nutrients losses and increase soil and crop productivity.

Azotobacter spp. are heterotrophic, nonsymbiotic, free-living nitrogen-fixing bacteria that live primarily in neutral or alkaline soils. This review presents the most current literature, following PRISMA flow guidelines, to provide a comprehensive and contemporary view of Azotobacter as a multifunctional biofertilizer, including its mechanisms of action on crop yield, soil health, and plant health. By producing growth compounds and affecting plant growth, Azotobacter has the potential to be used as microbial inoculants, boosting agricultural crop yields. Azotobacteria are free-living nitrogen-fixing bacteria that produce cytokinins, auxins, and other compounds that are key growth regulators and promoters. It protects plants from phytopathogens, promotes rhizosphere microorganisms, and safeguards plant health. Azotobacter-inoculated plants exhibit improved plant health through a variety of methods. For instance, speed up the synthesis of plant hormones like indole-3-acetic acid, remove stressors, fix nitrogen, degrade pesticides and oil globules, and metabolize heavy metals. Azotobacter application increased wheat yield by up to 30%, Maize by 20% and tomato by 20% compared with chemical fertilizers. Their application can improve crop yields, soil fertility, and plant health, offering an eco-friendly alternative to chemical fertilizers and supporting long-term soil management. Future research would focus on molecular mechanisms, strain selection, and integration with modern soil genomics to maximize benefits.

ContextThe rice-wheat (RW) system, spanning 13.5 million hectares in South Asia, is crucial for food security and livelihoods. However, intensive conventional tillage-based practices have harmed soil and environmental health, decreased productivity trends and increased greenhouse gas emissions. ObjectiveThis study aims to develop resilient, climate-smart cropping systems within the RW system, focusing on soil and crop productivity, economic viability, and reduced greenhouse gas (GHG) emissions. MethodsOver eight years, the study evaluated diverse parameters compared to farmer practices (FP) in seven scenarios (Sc), including one representing FP (Sc1) and six based on conservation agriculture (CA) principles. The study assessed system crop productivity, economic returns, soil quality (organic carbon; OC, nitrogen; N, phosphorus; P, potassium; K contents, bulk density; BD, soil aggregation, infiltration rates, microbial counts, and earthworm density), and GHG emissions. ResultsCA-based scenarios (Sc2 to Sc7) showed improved soil quality, lower bulk density, enhanced soil aggregation, and increased infiltration rates compared to Sc1. In the 0–15 cm layer, surface soil organic carbon (OC) and C stock were 63.7 % and 49.6 % higher, respectively, in CA-based scenarios. Additionally, available N, P and K contents in the surface layer increased by 10.2 %, 28.6 %, and 21.8 % under CA-based scenarios. Adoption of CA in intensified maize-based scenarios (Sc4 and Sc5) led to the increased system and economic yields, higher soil quality index (SQI), reduced GHG emissions and increased C stock compared to Sc1. ImplicationsThe study highlights that Conservation Agriculture (CA) practices and diversified crop rotations can address issues like falling crop productivity, reduced economic returns, soil degradation, and increasing environmental impacts in northwestern India's traditional rice-wheat system. However, widespread adoption requires government policies, including C credit payments and guaranteed markets with supportive pricing.

Soil health refers to the ongoing ability of soil as a living ecosystem to maintain environmental quality, support crop productivity, and ensure human health. Evaluating and enhancing soil health is crucial for ensuring more productive and resilient agricultural systems. The aim of this work is to assess soil health using both on-farm and computational methods. The study was carried out on a slope with textural variation at Ponta Grossa–Paraná State, Brazil. The slope was divided into three segments based on altitude and clay content: upper, middle, and lower positions. In each segment, twenty points were sampled, resulting in a total of sixty points along the slope. Soil health was analysed at these points by visual evaluation of soil structure (VESS), and samples were also collected to use the Soil Management Assessment Framework (SMAF) approach in the 0–0.10 m and 0.10–0.20 m soil layers. The indicators used in this approach were soil organic carbon, macroaggregates, bulk density, water-filled pore space, pH, phosphorus, and potassium. The data were analysed using analysis of variance, mean comparison with Tukey’s test (p < 0.05). In addition, principal component analysis was performed on the soil health index (SHI) and its components (chemical, physical, and biological) with clay content and VESS scores. The study discovered that the upper position had the highest clay content, lower visual scores (2.44), and a higher SHI (up to 0.80) compared to the middle (3.7 and 0.78) and lower positions (2.9 and 0.73). This study highlights the significant influence of soil texture, particularly clay content, on soil structural quality and health as assessed by VESS and SMAF. Higher clay content improved soil aggregation and health, while lower clay content in the middle and lower slope positions resulted in poorer structure. VESS proved to be an effective field-based tool for rapid assessment of soil health, complementing the more detailed SMAF framework. The integration of both methods is essential for the development of adaptive and sustainable soil management strategies.

There is a consensus among soil scientists, agronomists, ecologists, and others that soil health is important. However, there is variation in how different stakeholders think about it. Crop scientists and farmers may be most interested in how soil health affects crop yields, whereas ecologists and conservation groups are interested in soil health to minimize erosion or maximize soil carbon sequestration. For organizations that support research and dissemination of information like our Societies, USDA-NRCS, or the newly formed Soil Health Partnership and Soil Health Institute, variation in how soil health is measured and reported can make it challenging to create resources to aid landowners/managers in ways that they can improve soil health. Researchers at Virginia Tech and the University of Idaho recently conducted a meta-analysis to assess how soil health is measured. Publications listed with the Soil Health Institute were included in this analysis, specifically, those listed as either “Residue and Tillage Management, No-Till” or “Cover Crop.” A total of 192 unique peer-reviewed studies conducted across North America were used with publication dates ranging from 1943 through 2015. The authors report their findings and discuss how soil health research could benefit from a common framework in an article recently published in Agricultural & Environmental Letters (https://doi.org/10.2134/ael2018.06.0033). In these 192 papers, researchers reported a variety of measurements and methods. The authors of the meta-analysis grouped all measurements into 42 indicators that include physical, biological, and chemical properties (e.g., soil N, pH, and bulk density). Soil-sampling methods were highly variable with the authors reporting that 30% of studies only sampled the upper 5 cm of soil while 20% included depths greater than or equal to 30 cm. The most commonly reported indicator was soil texture, which was included in 85% of studies. However, the majority of these papers included soil texture as part of the site description and not as a response variable. Soil carbon and bulk density were also commonly reported in 50 and 40% of studies, respectively. Changes in crop yield associated with changes in soil health, which is of great interest to farmers, was reported in less than one-third of the papers. The results of the meta-analysis offer insight into which indicators offer the most information for those seeking to evaluate soil health. The authors combined the 42 indicators into six categories: physical properties, chemical characteristics, biological indicators, environmental states and fluxes, agronomic responses, and general indicators. Of these six categories, biological indicators, environmental states and fluxes, and agronomic responses appeared to be the most responsive to treatments or changes in management practices, and physical indicators were also important. Identifying the indicators that are sensitive to changes in management practices will be valuable for those working to inform farmers and regulators about soil health assessments and monitoring. Based on the results of this meta-analysis, the authors suggest a set of parameters for collecting data and reporting results in soil health studies. These include what they call basic “vital signs”: soil texture, pH, bulk density, and soil carbon. Additionally, they suggest measuring aggregate stability, infiltration rates, and microbial indicators, which appear to be highly responsive to management changes. “A common framework for soil health data should enable compilation of findings from various studies, making it critical that measurements are gathered with consistent protocols and reporting units,” the authors write. “For example, soil sampling should be standardized in terms of depths and number of replicates while accounting for different equipment and resources available to individuals and groups.” The authors also stress that reporting all results, even those that are neutral or negative, makes it easier to compare studies. Having agreement about a common framework for sharing soil health information could accelerate our understanding of the concept and provide consistency in messaging to farmers and landowners seeking to improve soil health. Corresponding author Ryan Stewart will be giving a presentation on this study at the International Soils meeting in San Diego next month: https://bit.ly/2A55amm. The original Agricultural & Environmental Letters article can be viewed at https://doi.org/10.2134/ael2018.06.0033.

ABSTRACTContinuous mono-cropping of rice-wheat (RW) system with conventional tillage (CT) based management practices have led to decline in soil health, groundwater table and farmers profit in north-west India. A medium-term (4 years) farmer’s participatory strategic research trial of basmati RW system was conducted to evaluate the effects of conservation agriculture (CA) based management practices on crop yields, water productivity, profitability and soil quality. Six treatments were compared varied in the cropping system, tillage, crop establishment and residue management. CA-based management under zero-till direct seeded rice-wheat-mungbean recorded 36% higher system yield than conventional till rice-wheat system (14.91 Mg ha−1). CA-based rice-wheat system and rice-wheat-mungbean system saved ~35% irrigation water compared to conventional RW system (2168 mm ha−1). Total water productivity (WPI+R) was improved by 67% with CA-based rice-wheat-mungbean system (0.90 kg grain m−3) over the conventional system. On system basis, 42% higher net return was recorded with CA-based rice-wheat-mungbean system compared to conventional system (USD 2570 ha−1). Mungbean integration in basmati RW system contributed 29% share in system net returns across the treatments. Soil chemical and biological properties were improved by ~40% and 150%, respectively, with CA-based management system.

Global warming may reduce maize yields and soil organic carbon (SOC), potentially threatening global food security and soil health. To address this concern in Northeast China, one of the world’s major maize production areas, the maize Agricultural Production Systems Simulator Model (APSIM) was used to evaluate how different tillage methods and straw return practices affect maize yields and SOC under future climate scenarios. The purpose of this study is to deal with the threat of global warming to the yield and SOC in the northeastern maize-producing areas, explore sustainable agricultural management strategies to stabilize the yield, enhance the soil carbon pool, counter the impact of climate change, and seek ways to ensure regional food and soil health. This study explored three tillage methods—plowing tillage (PT), rotary tillage (RT), and no-tillage (NT)—and two straw return methods—straw return (SR) and no straw return (SN)—under two Representative Concentration Pathway (RCP) scenarios: RCP4.5 and RCP8.5. The results showed that under the climate change scenarios: (1) For different tillage methods, no-tillage (NT) management showed the greatest increase in crop yield at 6.2%. SOC is highest under NT in the 0–20 cm soil layer under both straw return methods and climate scenarios. (2) For different straw return methods, SOC decreases when the straw is removed (SN) but increases when the straw is returned (SR) in both scenarios. Soil organic carbon density (SOCD) declines but can be mitigated by straw return. (3) Overall, tillage and straw return practices can significantly impact SOC under RCP4.5 but not under RCP8.5. Tillage and straw return practices together explain more than 50% yield changes under climate change scenarios. Through the modeling approach, this study revealed the potential benefits of integrating tillage and straw management practices to sustain maize yields and SOC. These practices can mitigate long-term climate change impacts on crop yields and soil health.

The major farming system in India is the rice-wheat system, however it is no longer sustainable due to issues with soil health and climate change. The irrigated rice-wheat system's high yields have resulted in the production of vast amounts of agricultural leftovers. The frequent burning of rice straw in north-western India results in nutritional losses and significant air pollution that is harmful to human health. Crop residue management innovations can aid in achieving sustainable productivity to prevent straw burning, enable farmers to use less fertiliser and water, and lower risks associated with climate change. Crop residues contain significant amounts of plant nutrients, and wise use of these nutrients would improve the management of nutrients in the rice-wheat system. Long-term residue recycling studies have shown changes in the soil's physical, chemical and biological health. Another option for the management of crop residues is to use some of the excess residue for the production of biochar, which can be used to improve soil health, increase nutrient use efficiency, and decrease air pollution. Other options include mushroom cultivation, which can turn unusable crop residues into valuable food, surface mulching for weed and moisture control, and the production of biofuel and compost. The decomposition of soil residues greatly increases organic carbon and other nutrients in the soil. This collected review literature addressed the potential for residues and possible options for the efficient management of crop residues in the rice wheat cropping system to improve crop water productivity and soil health.

The rice-wheat system (RWS), managed over 10.5 Mha in the Indo-Gangetic Plains of India suffers from production fatigue caused by declining soil organic matter, multi-nutrient deficiencies and diminishing factor productivity. We, therefore, conducted a long-term field experiment (1998–1999 to 2017–2018) in Modipuram, India to study the effect of continuous use of farmyard manure (FYM) as an organic fertilizer (OF), mineral fertilizers applied alone (RDF) and their combination (IPNS), as well as the inclusion of forage berseem (IPNS+B) or forage cowpea (IPNS+C) on crop yield, soil health and profits. The long-term yield trends were positive (p < 0.05) in all treatments except the control (unfertilized) in rice, and the control and RDF in wheat. Although the yields of rice, wheat and RWS were highest under IPNS treatments (IPNS, IPNS+B, IPNS+C), the maximum annual yield increase in rice (9.2%) and wheat (13.7%) was obtained under OF. A linear regression fitted to the yield data under different IPNS options revealed a highly significant (p < 0.001) annual yield increase in rice (5.1 to 6.6%) and wheat (6.8 to 7.7%) crops. Continuous rice-wheat cropping with RDF brought an increase in soil bulk density (Db) over the initial Db at different soil profile depths, more so at depths of 30–45 cm, but inclusion of forage cowpea or berseem in every third year (IPNS+B or C) helped to decrease Db, not only in surface (0–15 cm) but also in sub-surface (15–30 and 30–45 cm depth) soil. Whereas soil organic carbon (SOC) increased under OF, IPNS and IPNS + legume (B or C) treatments, it remained unaffected under RDF after 20 RW cycles. The inclusion of legumes along with IPNS not only helped to trap the NO3–N from soil layers below 45 cm but also increased its retention in the upper soil (0–15 cm depth). On the other hand, RDF had a higher NO3–N content in the lower layers (beyond 45 cm depth), indicating downward NO3–N leaching beyond the root zone. A build-up of Olsen-P was noticed under RDF at different time intervals. The soil exchangeable K and available S contents were maximal under OF and IPNS options, whereas a decline in DTPA extractable-Zn was recorded under OF. Overall, RWS economics revealed that OF treatment involved the maximum cost of cultivation (US$1174 ha−1) with the least economic net return (US$1211 ha−1). Conversely, IPNS + legume (B or C) had lowest cost of cultivation (US$707 to 765 ha−1) and a significantly higher (p < 0.05) net return (US$2233 to 2260 ha−1). The study, thus, underlines the superiority of IPNS over RDF or OF; the inclusion of legumes gives an added advantage in terms of production sustainability and soil health. Further studies involving IPNS ingredients other than FYM is needed to develop location-specific IPNS recommendations.

The influence of soil management on soil health: An on-farm study in southern Sweden