This is another article on soil health in this special edition on soil health of this journal. One question raised is "What is soil health"? Also how does one describe it to non-soil scientists and why it is so important to everyone? The authors of this paper who organized this series of papers on soil health share their thoughts and own opinions on soil health in this paper. The conclude by saying "Our goal is that each of you will be enriched by the articles in this issue and the impact of soil health on conservation and the future of our ecosystem."

This paper talks about the role of soil as a basis for all terrestrial life as well ecosystem services for nature and mankind. It is essential to protect, restore and manage soils in a sustainable way so that soil health is maintained and improved. This will require humans working together including the various stakeholders in the public, private, scientific and extension groups but also policies to make sure the soil is a protected resource. 

I included this book that was published in 2021 because it deals with the role of cover crops that are becoming more popular in modern agriculture and used in sustainable agriculture like conservation agriculture to provide the essential surface mulch needed to make no-till systems productive. This book is an encyclopedia of cover crop management by 2021. Papers in the 18 chapters indicate the long-term benefits for soil health, structure, water quality, nutrient contributions, soil biodiversity, air quality and climate change. The book looks at the "whys" as well as the "hows" for different locations and how to terminate them when needed. As part of a continuous no-till system, cover crops provide long-term biological, chemical and structural benefits. The resulting increase in soil organic matter means the agronomic crop yields benefit from better water infiltration and water holding capacity, greater availability of nitrogen and other nutrients, deeper rooting, and increased soil microbial activity in the root zone.

This study from China investigated the erosion processes and carbon dynamics across eroded slopes after adopting various conservation practices based on the data obtained from field experiments across the globe. Their results interestingly showed that adoption of CA compared to CT significantly did not reduce runoff but did lead to a significant reduction in sediment loss. CA also significantly increased soil organic carbon (SOC) in the top 10cm layer and reduced SOC loss. The results further highlighted the critical contribution of straw mulching in erosion control, soil organic carbon loss reduction, and soil organic carbon accumulation, while reduced tillage represented the least effective measure. 

This paper from Europe used a Meta-analysis to to evaluate the impact of management practices related to carbon and nutrient, vegetation, pest and disease and soil management, as well as grazing management on soil biota and soil biology. They screened 698 articles and came up with 90 that were eligible with a total of 790 pairwise combinations and 74,526 observations. Their study showed what agricultural practices improve or reduce soil biology that is useful for selection of sustainable farming systems. They found that reduced tillage, organic fertilization, cover cropping and intercropping resulted in positive improvements in soil health factors. They also developed a “Utility-Robustness” scoring system for soil actors, using a systematic framework to inform biological indicator selection tailored to specific management contexts.

This long-term field experiment with Winter wheat looked at 3 tillage systems: conventional (CT), reduced (RT), and No-till (NT) since 1995. They collected data on SOC, microbial biomass, and enzymatic activity in four-year crop rotation periods from 2005-2024. There were 3 rotations: winter oil seed rape, winter wheat, pea, and winter wheat.Data was collected from 3 crop depths: 0-10, 10-20, and 20-30 cm. Residues were incorporated in CT, partially in RT and left as surface mulch in NT. Results showed that NT had the highest C-sequestration followed by RT and CT. The weather conditions during the year (abundance of precipitation) influenced crop yields significantly more than the tillage practices with wheat yields and N in grain the highest in CT followed by RT and lowest in NT. NT treatments increased the organic carbon and microbial activity in soils.

This paper identifies some knowledge gaps and opportunities to narrow the soil carbon gap existing in croplands today. They suggest that adoption of regenerative, CA and cover crops without understanding the mechanisms for carbon capture will not result in C capture in the soil profile. Even though NT results in improved soil carbon, most of this is found in the soil surface.. They suggest that increased plant biomass is needed to improve C capture by increasing higher above and below ground biomass. They conclude that many factors affect C gains, but the most critical  factor is boosting biomass C into the soil profile  when trying to narrow the C gap. 

This paper mentions that maize, wheat and rice account for 90% of the total cereal production globally. They suggest that a new approach to cereal production is needed to overcome food insecurity, climate changes and unsustainable land use. They propose that integrated crop management (ICM) is an avenue to explore. This article reviews 108 studies from literature over the last 23 years.The review the data from Asia, China, USA, and Africa. Their data shows that ICM increased yields in rice, wheat and maize but despite this potential, widespread adoption faces technical, climate-related and economic issues.  They suggest that overcoming these issues requires targeted training, improved extension, and supportive policies.

This paper starts by saying conventional agriculture is labor, energy and water inefficient and so reports of experiments to identify more sustainable, productive and efficient crop production in a maize-wheat-mungbean system started in 2009-10 and assessed in 2018-19 to 2019-20. Treatments included CA-based bed planting methods such as permanent narrow, broad and flat beds with and without retention of crops residues and 75% and 100% of the recommended dose of nitrogen (N) were compared with conventional tillage (CT) treatment. Results show that adopting the CA practice involving a permanent broad bed with residue using 100% N in this maize-wheat-greengram system was more productive and efficient for nutrients, water, and energy.

This paper looks at how nature manages resources and describe living soil and its productivity using nature's laws to improve soil management. They promote the three principles of CA to achieve improved living soils since conventional soil tillage and poor crop diversity are resulting in soil degradation and loss of productivity. Mechanical tillage is not found in natural ecosystems whereas CA emulates natural systems leading to reversal of soil degradation, improved soil health that leads to improved yields and economic and environmental benefits to all farmer land sizes. The CA nature based systems are recommended to offset the issues of climate change and tillage induced soil degradation to help with future food security. 

Crop residue is crucial in CA management to improve soil health and increase yields. This paper from India looks at a residue cleaning system (T1) to help overcome the challenges of residues left after combine harvesting and included design, development and field testing. They first tested the equipment in a soil bin before testing in a field trial consisting of a wheat-greengram-maize cropping pattern and comparing with the Happy Seeder (T2) (an earlier equipment used for sowing into crop residue). T1 and T2 had similar yields but T1 required less energy although it slightly higher carbon emissions. They concluded that T1 had lower B/C ratio compared to T2 but increasing the number of rows in the T1 treatment could enhance field capacity, potentially reducing carbon emissions and improving economic returns.

This study analyses and compares the economic indicators of conservation reduced tillage (CT) widely practiced in Central Europe with those of conventional ploughing tillage (PT) assessing the effects of CT compared to PT on yields and profitability from 2004-2023. The study covered 83 ha in 10 paired plots (from year 13 onwards, 76 ha in 9 paired plots), including extreme weather conditions and 6 crops. During the transitional period, profit under CT decreased by an average of 11.9% compared with PT, but subsequent periods indicated positive results, 2.3% increase in gross income and 13% higher profit. Over 20 years, material costs for CT plots were 1.9% higher and operating costs were 9.8% lower compared with PT. Their results suggest shifting to reduced tillage is worth it. It would be interesting to have seen the profits if the CA system was used in this comparison. 

This paper looks at the impact of CA in an Ethiopian district on crop productivity using cross-sectional household data from 322 subjects in two agro-ecological zones. There were 168 CA and 154 non-CA farmers. The project's findings highlighted the need for policies that support and enable a more frequent and successfully established communication link between farmers with agricultural experts at the regional, zonal, and district levels, as well as agricultural extension personnel at the local level. There is a need to adopt crop and soil management systems on farmland,that results in improved soil quality consistently for improved crop productivity.

This is one of several papers on the importance of soil health in modern agriculture especially for securing future food security written by a renowned soil scientist. He talks about a disturbance based classification of agricultural systems that includes tillage and chemical use: does the system allow , minimize or avoid physical or chemical disturbance in soil ecosystems and do these systems help with reversing the degradation of soil and its health? This paper discusses conventional, organic, no-till, regenerative, and regenerative organic farming in terms of physical and chemical disturbance. 

This is a chapter from the Cover Crops and Sustainable Agriculture book listed next that is devoted to cover crop use in conservation agriculture. This chapter looks at the issue of an expanding global population (10 billion by 2050) with a traditional farming system that uses intensive tillage and monoculture that is slowly degrading the soil, the environment and the ability to feed the future population, especially as climate change adds a further challenge for food production. This chapter provides information on cover crop mixes that are relevant for conservation agriculture to not only improve the benefits of a surface residue mulch needed for no-till systems but also a way to improve soil health vital for sustainable agriculture and future food security.

This paper from India starts by saying India with 121 million small and marginal holdings, faces challenges from a growing population, limited land, and restricted resources.Their review identifies potential innovative technologies suitable for resource poor farmers and what effective ways are needed like public-private partnerships, cooperative farming, and custom hiring centers to overcome adoption barriers and identified enabling factors such as funding, education, and institutional support. They also suggest that a multi-faceted approach with policy, financial, and educational support is essential for adoption. They conclude that findings are relevant to policymakers and development practitioners focused on enhancing food security and resilience in smallholder farming.

This paper from Ohio State University's Triplett-Van Doren long-term tillage and crop rotation experiment (one of the oldest NT experiments in the World) looked at the temporal dynamics of soil N and C pools in a maize growing season, in a 55 year old tillage and crop rotation experiment. Tillage treatments were no-till (NT) + residue, Chisel-till (CT) + 30% residue and moldboard till (MT) - residue incorporated. There were 3 rotations: continuous maize, maize-soybean (2-year rotation), and maize-forage-forage (3 year rotation). Their results suggest that crop diversification with perennials enhances soil C and N; NT has stronger effects in clay loam than silt-loam soils; and although C and N pools vary seasonally, long-term management effects persist throughout the growing season.

This paper from New Zealand starts by saying soil health decline is a major constraint to achieving higher yields and looks at the interaction of tillage, legumes and nitrogen on reversing declines in SH for a cotton-wheat on a bed planting system. There were two tillage systems; NT and Conventional tillage (CT). Three legumes: soybean, mungbean, and mash bean. 2 nitrogen levels. Results showed that the best treatment for soil organic matter and microbial population (improved soil health) was cotton + mungbean-wheat with NT and the recommended N and a significant increase in wheat yield compared to CT treatments. 

Nepal agriculture is challenged by environmental degradation, labor shortages, and increasing feminization of farming as a result of male outmigration. CA offers a solution but adoption needs to increase. This paper examines issues related to adoption CA as more women become empowered in agriculture. The surveyed 383 farmers across 3 Districts and found that 73% of respondents were willing to adopt CA because of climate concerns, economic incentives and market access. They believe that CA enhances sustainability, resilience, and income are also more likely to engage, while market dissatisfaction presents a challenge. Getting subsidies is associated with adoption of CA. Barriers for women include household responsibilities, lack of education and training, and limited financial access. They conclude that targeted policies, institutional support, and market-based incentives are essential for increasing adoption by women farmers. 

This article explores the interaction of genotype (16 cold tolerant) and tillage (3) for chickpeas in dryland areas of Iran over three cropping seasons. Tillage treatments were moldboard with residue removed (CT); minimal tillage (MT) with a chisel plow with residue; and no-till (NT) with residue retained. Results were positive for no-till + residue with increases in SOC, potassium, phosphorus, nitrogen and soil moisture compared to the start of the experiment. There were differences in performance between the different genotypes with some better with no-till and others with MT and others with CT. Chickpea genotypes cultivated under the NT system demonstrated superior performance (41%) in comparison to those grown using conventional tillage (CT) practices during the third year.

This paper indicates that CA adoption in India is mostly in the irrigated IndoGangetic Plains and typically uses agrochemicals. This study explores the adoption of CA in a rainfed area of Central India  where farms are organic and look at the factors that led to adoption. Results showed that the variables that were important were farmers’ age, household size (a proxy for labour), extension frequency, farmer’s initiative-taking ability, farming experience, and market accessibility. The majority (90%) of the adopters indicated improvements in soil health, reduction in water use, and increases in yields and quality. They also indicated (80%) that CA led to lower costs, and higher incomes. However, biomass was an issue since farmers use the residues for cattle feed. The conclude that "To scale CA and produce food sustainably in rainfed areas, it is necessary to initiate supporting policy and institutional interventions that would improve extension, biomass production, and availability within the farming system.

This is an interesting review of how Brazilian farmers moved from a tillage intensive farming system to one that used no-till, permanent soil cover, and rotations or conservation agriculture. In Brazil over 52 years, no-tillage systems (NTS) evolved allowing Brazil to move from a major importer of agricultural products to one of the largest producers and exporters globally. This paper reviews how this came about. It was spontaneous without any specific incentive program or policy. It was also because of the farming sector in Brazil who was responsible for this mobilization and sought alternatives that led to less impacting soil management allowing a more sustainable intensification of agriculture. The farmer sector included farmer organizations and companies responsible for supply of inputs and equipment suitable for seeding in no-till soil with permanent residue soil cover. Academia and research acted in the background at the strat but have now become more active. 

This interesting article from Japan looks at a solar powered mower integrated into a NT system that reduces GHG emissions. This study evaluates NT and intercropping with solar-powered machinery in organic cherry tomato production. They compared two tillage methods (NT} and rotary tillage (RT)] and two cropping patterns [cherry tomato/peanut intercropping (TP) and monocropping (M)]. Solar-powered robotic mowers replaced conventional mowers in NT to enhance environmental benefits. They assessed the results by crop yield, energy efficiency, carbon footprint, and profitability. They conclude that "NT-TP's potential to enhance yield, energy efficiency, and profitability while reducing the carbon footprint, makes it a sustainable management system for organic farming. 

This study from Poland looked at various tillage methods and their impact on soybean yield and quality. The four tillage methods were: a) Plowed tillage plus conventional row seeding (PCR); b) Plowed tillage plus strip till planting (PSD); c) No plough tillage + strip drill planting (NSD); and d) No-tillage + strip drill (ZSD). The paper presents the data on these 4 treatments. ZSD enhanced protein levels and stabilized protein and fat yields. They conclude that future studies should explore how tillage practices affect soil health, economic sustainability, and yield stability over time, especially under changing climatic conditions.

The authors mention that there are 3.5mha of CA in India but little data on the effects of CA on soil nutrient dynamics like N, P, and S. They have a nine year study on these nutrients in a maize-wheat cropping pattern that compares CA with conventional methods. Results show that CA and N addition significantly enhanced various soil chemical properties and microbial biomass compared to CM for N, P and S and concluded that "These findings contribute crucial knowledge for sustainable development by offering valuable perspectives on N, P and S management strategies."