Conservation Agriculture Research Updates - March 2026

Tillage practices have been used by farmers for centuries to prepare soil, manage residues, and control weeds but with consequences for soil health and soil degradation. This global review critically examines and synthesises current research on the impact of various tillage practices like conventional (CT), reduced (RT), and no-till (NT) tillage systems on greenhouse gas emissions (GHG), soil health and agricultural sustainability from scientific papers written on this subject. Some results presented show that CT increases C02 emissions through soil disturbance and oxidation of organic matter, while RT and NT reduce C02 and mitigate N20 and CH4 emissions. NT also enhances water retention and thus drought stress. The author concludes that "RT and NT practices emerge as pivotal strategies for reducing greenhouse gas emissions and advancing agricultural sustainability through improved soil health and water retention."

This is another article from the Central Valley of California that assesses 20 years of conservation agriculture management that looks at soil physical, chemical and structural properties comparing reduced tillage with cover crops with conventional tillage without cover crops. In brief, the CA management achieved dynamic equilibrium characterized by fundamental shifts in carbon stabilization pathways. Water stable aggregates also exhibited 136% greater stability with CA than with CT. This paper discusses the implications of these differences. They conclude "This mechanism shift represents a new soil system equilibrium that maintains enhanced functionality and continued carbon sequestration potential in Mediterranean agricultural systems."

This paper from China compares the Agricultural Eco-Efficiency (AEE) between conventional tillage (CT) and conservation tillage (CA = no-till plus residue mulch) 2000-2020 using various models. Their results overall show that the AEE under conservation tillage is greater than under CT with both systems exhibiting an initial decline followed by an increase over time. However, there was differences between provinces because of contrasting tillage systems an d trends over time. They conclude "The long-term evolution of AEE in individual provinces is shaped by a combination of geospatial patterns, initial conditions, and other influencing factors. These findings provide valuable insights for policy formulation, the dissemination of conservation tillage, and the advancement of sustainable agricultural."

This paper uses the term Resource Conserving Technologies (RCT's) as practices that help reverse the negative affects of climate change on food and water productivity. RCT's they include are CA, cover crops, mulching, drip irrigation, soil moisture sensors-based smart irrigation, rainwater harvesting, site-specific nutrient management, leaf color chart, fertigation, and precision agriculture that can result in long-term sustainability by enhancing food production and sequestering soil carbon in conventional field farming. They can also reduce greenhouse gas emissions (GHGs), result in higher yield and water savings. Some RCT's require high-cost machinery and it is suggested they should be tested in diverse production systems for sustainability and large-scale adoption. 

This review article looks at the relationship between agroecology and water management in order to identify strategies for sustainable agriculture in North African countries. The paper looks at agroecological approaches to water management, including agroforestry, conservation agriculture, water-efficient irrigation, and landscape design. It looks at integrating biodiversity for water regulation, leveraging ecosystem services for purification, and adopting advanced technologies, such as precision agriculture and remote sensing, and policies needed for efficient water management. They conclude that there is a need for interdisciplinary collaboration among agronomists, hydrologists, ecologists, policymakers, and local communities to develop holistic approaches that seamlessly integrate agroecology and modern water management, ensuring sustainable agricultural systems in the region. 

This paper looks at land in the Lower Mississippi Delta where 70% of the land is furrow irrigated and where NT and bed planting issues hinder NT adoption. Ridge making and furrow maintenance are crucial in this area. This paper looked at the impact of adopting long-term NT compared to conventional tillage (the traditional system). NT increased soil total nitrogen, organic matter, organic sulfur, magnesium, calcium, cation exchange capacity, and stored soil water compared to CT during 4 years of soybean production following 11 years under corn. CT resulted in loss of nutrients as a result of disturbing the soil surface. CT also developed a thick plow pan at 10cm depth. I wonder if they should think of having permanent NT beds with residue retention that is practiced successfully in other parts of the World.

Sugarcane is an important bio-energy crop in India buy yields are low. This paper looked at ways to improve productivity by using CA based tillage, surface residue retention and nutrient management. There were 3 tillage treatments, conventional (CT), reduced (RT) and just one cultivation. Residue was with and without. After tillage beds were formed for planting sugarcane. Results showed yields were better for the one cultivation and RT compared to CT and adding residue was better than no residue. The paper also describes the use and results from fertilization and energy consumption. They conclude that integrating reduced tillage, trash retention and appropriate fertigation practices has a potential to improve sugarcane productivity vis-a-vis profitability, and sustain soil and environmental quality in sugarcane production systems, as prevalent in water scarcities regions.

This chapter describes the challenges facing this part of the World that includes Morocco, Algeria, Tunisia, Libya, Egypt and Sudan mostly due to high population growth rates, youth unemployment, increasing food needs, variable income levels and threatened fragile natural resources. The chapter describes the introduction of conservation agriculture and its adoption in this area and how there was a need to dismantle barriers and promote this management system to improve replace traditional systems that result in degradation of the environment and lead to reduced productivity.

This paper from Japan reviewed 68 papers to look at 13 field management categories in terms of importance for mitigation of climate change.The management categories were evaluated in terms of yield, area-scaled greenhouse gas emissions (GHG), and yield-scaled GHG emissions against base management practices. Yield increases varied from -6 to +12%. Only non-puddling increased yield and reduce both types of GHG emissions. Water management, (alternate wetting and drying or single and multiple drainage and notillage), reduced both GHG emissions, but reduced yield slightly. The paper concludes and recommends nonpuddling, water management and no-till as climate mitigation options, but suggests other categories like soil fertility be included.

SOC sequestration is an important tool for mitigation of climate change within the EU soil strategy for 2030. This review synthesizes existing knowledge, identifies knowledge gaps and provides research recommendations on trade-offs and synergies between SOC sequestration or SOC accrual, non-CO2 GHG emissions and N leaching related to selected soil management strategies using 87 peer-reviewed articles categorized under tillage management, cropping systems, water management and fertilization and organic matter (OM) inputs. This review provides guidance for policymakers and a framework for field experiments and model simulations.

This paper states that the future of the rice-wheat system, a major food security system for South Asia is at stake because of "Traditional practices like conventional tillage (CT) residue burning, and indiscriminate use of groundwater with flood irrigation". As such this paper studies the role of CA, mungbean integration, water, N, and energy use efficiency in the RW system. The results showed that bundling CA with subsurface drip irrigation (SDI) saved substantial water in both rice and wheat compared to traditional farmer practice. Based on the 3-year mean, CA with SDI (mean of Sc5–Sc8) recorded −2.5% rice yield, whereas wheat yield was +25% compared to farmers practice and rice and wheat yield under CA with flood irrigation were increased by +7 and + 11%, compared to their respective CT practices. Mungbean integration added 26% to productivity. They concluded that CA with SDI for precise water and N management proved to be a profitable solution to address the problems of groundwater, residue burning, sustainable intensification, and input (water and energy) use with the potential for replication in large areas.

This South Dakota study assessed the impact of tillage CT and NT); crop rotation: 2-year corn-soybean, 3-year corn-soybean-oat and 4-year corn-soybean-oat-wheat; cover crops (cover crop [CC] and no cover crop [NC]); and drainage (tile drainage [TD] and without drainage [ND]) on soil organic matter (SOM), bulk density, wet aggregate stability (WAS), and field-saturated hydraulic conductivity (Kfs). Soil samples were collected over 2 years from five depths and analyzed for SOM, bulk density, and WAS. NT increased soil bulk density, soil organic matter, and wet aggregate stability (WAS) for the 0- to 10-cm depth but decreased Kfs within the soil profile compared to CT. CC and tile drainage(TD) had minimal impact on SOM, bulk density, WAS, and Kfs.

This paper looks at the role of interseeded cover crops (CC) to improve water storage, reduce runoff, increase infiltration and decrease evaporation. The paper reports the effect of interseeding CC in 4 NT rotations by USDA. All rotations included, maize, soybean and wheat. They also used different cover crops. Estimated evapotranspiration was lower for CC compared to NC systems in 2018, while greater estimated infiltration was observed for CC compared to NC systems in 2019.4-year averaged maize yields and WUE were higher in CC than NC. The returns from better yields offset the costs of establishing CCs. They conclude interseeded CCs in humid area of US is beneficial.

This article from China starts by saying short term no-till increases bulk density, reduces total porosity and microporosity that affects aeration. Their goal was to see if over time NT can overcome these negative effects. They used a 4-year field experiment that used rotary tillage (RT), subsoiling (SS) and NT and evaluated soil gas diffusivity and water retention across a range of soil matric potential. They used Undisturbed soil samples (0-40 cm depth) using X-ray Computed Tomography (X-ray CT) to characterize pore structure. Results showed that NT reduced total soil porosity and macroporosity in the upper 30 cm compared to RT and SS but increased plant-available water content. NT also maintained higher gas diffusivity under wet conditions by forming irregular-shaped pore networks that increased specific diffusivity compared to RT and SS. They conclude that "NT effectively balances soil air-water conditions at higher moisture levels despite initial compaction, underscoring its potential waterlogging resistance."

This research looked at long-term adoption of residue retention on soil-water and temperature for wheat grown under CA in both a field experiment and crop model simulation using the APSIM (Agriculture Production System Simulator) model. Two tillage practices were NT + Residue retention (NT+R) and CT with residue incorporation (CT+R). The results indicated that the model accurately simulated crop phenology, leaf area index, above ground biomass, and grain yield under both tillage treatments. Soil water content, transpiration and drainage were higher in NT+R compared to CT+R. Evaporation and soil temperature were higher in CT+R. The authors were happy with the APSIM model for identifying the effect of tillage and residue on wheat yield components. 

This paper looks at the impact of no-tillage (NT) and conventional tillage (CT) on soil water and physical properties in Romania using undisturbed soil columns from a field experiment that was a continuous cropping system for 8 years with a 4-year rotation (wheat, maize, sunflower and peas). Various soil physical and water measures were taken. The various measurements can be found in the paper abstract. They conclude that the "findings demonstrate that long-term NT improves key soil hydro-physical properties, supporting its integration into sustainable farming systems to balance productivity and environmental stewardship."

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 the rice-wheat system in Eastern India where smallholder farmers are using excessive water and nitrogen with soil degradation. They used field studies and a crop simulation model to assess resilience, viability, and sustainability of this cropping system under CA with different irrigation methods and nitrogen rates. They had 4 treatments from the puddled transplanted rice (PTR) and zero-tilled wheat (ZTW) with flood irrigation to direct seeded rice (DSR) fb ZTW with sub-surface drip irrigation and 75% and 100% recommended N and a N control plot. The DNDC model accurately predicted soil mineral N. DSR-ZTW with drip irrigation  enhanced sustainability and productivity compared to PTR-ZTW and reduced methane emissions by 70-80%. This system also provided the highest system yield, lowered water losses and improved N use efficiency, and reduced GHG emissions. 

This report used a multilocation and multiyear trials to compare direct seeded (drilled and broadcast) with puddled transplanted (PTR) Aus (spring) rice using three rice varieties and 3 landscape positions (high, high-medium and lowland) in 3 different Districts in Bangladesh. Measurements included yield, profit, energy use efficiency and and productivity, Global warming Potential (GWP), and emissions. They conclude that DSR is more environmentally sound and economically viable and a climate-smart system and more suitable for highland and medium highland landscape positions. The paper did not mention issues of weed control in the abstract. This is probably a major issue when adopting DS rice.

This paper from India looks at the causes of a plateau in rice-wheat yields in South Asia. They used a 2-year on-farm study to look at wheat productivity in a RW system. They introduced various system optimization practices (SOP) that include legume inclusion, NT wheat, Direct seeded rice, and bed planting. Benefits of SOP's were reduced global warming potential, reduces water use, reduced weed density, higher partial factor productivity, wheat yield and net return increases, lower energy use compared to traditional practices. They conclude that wheat production with SOP's of legume inclusion and zero tillage achieve higher productivity and profitability with less environmental footprint in the Indo-Gangetic Plains and similar agroecological regions.

This study was initiated since traditional irrigation systems in the region are suffering from water scarcity. This study looks at sub-surface drip-irrigation (SSDI) and fertigation systems to increase irrigation water efficiency and water productivity, root systems and soil water balance in cotton–wheat cropping systems (CWCS). Results show that SSDI enhanced root systems and showed more secondary roots and root length in cotton and wheat. This also resulted in about 43% water saving compared to flood irrigation. Fertigation through the SSDI resulted in a 20% reduction in fertilizer needs. This SSDI system is now being promoted in dryland areas of the region that need irrigation to grow crops.They are also promoting CA practices that use no-till and residue mulch to improve soil properties.

This article is a three field study that looks at CA as a cost-effective alternative  to conventional tillage (CT) in rice-wheat systems in Karnal, Haryana, India using a flooded (FL) and sub-surface drip (SDI) irrigation. Results show that in rice, in ZT direct seeded rice with residue (+R) and SDI recorded 73% less weeds than the CT-puddled transplanted rice after 3 years. However, the ZTDSR without residue (R-) with flooding had the highest weed density and weed dry matter 37% less rice yield after 3 years. The paper lists the various weeds present. The same was found in wheat with the lowest WD and WDM in the ZT + SDI in year 3. The CA system improved yields over CTRW systems in weed free (WF) conditions, regardless of residue and irrigation management and should be recommended for RW systems.

Soil sodicity is expanding in arid and semi-arid areas of the world. This paper examines the reclamation potential of CA based management on this soil issue. They look at NT, use of legumes in rotation, residue mulch (R+), and sub-surface drip irrigation (SDI)  for 3 years in a rice-wheat system in India. The paper provides detailed results on productivity, economics, water and N use efficiency, soil pH, exchangeable sodium percentage, extractable anions, soil organic carbon, soil solution cations. They conclude that CA practices can reduce sodicity and improve soil chemical properties for a profitable crop production.

This review looks at the challenges of meeting food demands in South Asia complicated by climate change. They contend that CA can help resolve challenges of soil health, climate change, water scarcity, pollution, profitability and human health. This review uses published literature to look at how CA affects SOC and therefore soil health, carbon sequestration and GHG emissions. The results from several studies show CA increased SOC and improved soil health mainly in the surface layer. CA also made a positive impact on nutrient availability. The present gaps in knowledge of soil health assessment and research to fill the gaps are also included in this chapter.

This paper's objective was to identify suitable agricultural strategies with high yields, energy use efficiency (EUE) , and carbon use efficiency (CUE) for an array of different crops grown in India - cereals, legumes, oilseeds, and sugarcane in both rainfed and irrigated cropping systems. Irrigated systems had higher environmental impact (EI) and carbon footprint (CF) than rainfed systems. But rainfed crops had higher CUE than irrigated ones.  Adoption efficient irrigation strategies (micro irrigation), enhanced fertilizer use efficiency (site specific nutrient management or slow release fertilizer), conservation agriculture (conservation or reduced tillage) rice cultivation methods (SRI or Direct seeded rice) were some mitigation strategies identified..