Conservation Agriculture Research Updates - December 2025

This paper from Canada looks at application rates of Glyphosate (GBH) to terminate cover crops and how this influences soil microbial communities. They used 3 GBH application rates in maize, soybean and wheat fields grown with direct seeding (NT) with and without cover crops. Results showed that DS+CC did not significantly impact microbial richness compared to DS, but did alter specific abundance among prokaryotes and eukaryotes but that the three crops significantly influenced the composition of eukaryotic communities in 2018 and 2019, but not prokaryotic communities. They conclude that the study calls for sustainable agricultural practices that preserve microbial diversity, which is essential for maintaining ecosystem services and soil health.

This paper looks at the impact of CA on durum wheat in Tunisia as a possible way to mitigate climate change. They looked at yield and water use efficiency. They assessed this over 12 years looking at conventional (CT), minimal (MT) and no-till (NT). Note that their weather data shows a significant decrease in precipitation and increase rain-free days over these 12 years. Results showed that NT had the smallest decrease in yield and the smallest coefficient of variation and thus greater stability. They concluded that the benefits of CA are particularly pronounced in years with extreme drought events, highlighting the importance of adopting such agricultural innovations to mitigate the impacts of climate change.

This 5 year study from Lithuania,  looked at soil physical and earthworms as indicators of soil health following conventional (CT) and no-tillage (NT) across 3 rotations; three crops per rotation (with three variants), two-crop rotation (with two variants), and monoculture winter wheat. Earthworm abundance had a strong negative association with bulk density and a positive correlation with total porosity in the upper soil layer. Earthworm numbers were similar between CT and NT. Rotations affected earthworms more than tillage with with 3 and 2 crop rotations having more earthworms than monoculture.

This paper analyzed the effects straw mulch (SM) on NH3 and N20 emissions and leaching and runoff N losses versus non-mulching. Results showed that soil N20 emissions increased with SM but N leaching and runoff was reduced compared to no mulch. Soil nitrate, dissolved organic N, and microbial biomass N increased significantly after SM adoption. A long-term SM regime (duration>5 years) or SM combined with a low N application rate or straw application rate can reduce N runoff while avoiding the stimulation of NH3 volatilisation and N2O emissions. 

This paper looked at the combined influence of tillage and crop management (conventional (CT) and no-tillage (NT) with living mulch (LM)) and weeding regimes on nematodes, free living and parasitic in the Madagascar highlands 7 years after the establishment of the experiment. Results showed that the population of free living nematodes was almost 4 times more in NT+LM than CT. But plant parasitic nematodes were the same in abundance for both tillage treatments but differed in taxonomic  composition. They concluded that CA and no-weeding proved beneficial for promoting free-living nematode communities but also to decrease the overall plant parasitic pressure through plant diversification. As no weeding may nonetheless affect crop yield, a trade-off has therefore to be found to promote soil ecosystem services while maintaining crop production.

This study assessed the 10 year effect (experiment started in 2012) on CA practices on soil physical properties in a sub-humid area of South Africa. It had 16 treatments and 3 replications. They looked at CA vs CT, 4 rotations, and plus and minus residue cover. They collected soil samples from 3 soil depths in 2023/2024 for various soil physical measurements. Their results showed that tillage practices had a greater impact on bulk density (BD), porosity (phi) and aggregate stability (AGS)/ stability index (SI) compared to crop rotations and residue management. Rotations with soybeans had lower BD values that ones without soybeans and the authors suggest this maybe the result of faster soybean residue decomposition than maize and wheat residues. R+ plots had higher gravimetric water content and higher volumetric water content than R- plots, due to the substantial amount of SOM returned by residue decomposition. 

This paper suggests that CA is often though to under perform in high rainfall areas like Northern Zambia. This paper evaluates a long term (9 year) study in this area of maize cropping systems and rainfall variability on yield, , soil pH, and SOC. Three CA systems were compared to 2 conventional systems. Results showed despite rainfall variability across years, CA systems did better than conventional systems especially in low rainfall years. However, bed planted traditional systems out performed CA systems in high rainfall years. However over time yield declined faster in the conventional system than the CA systems as nutrients declined. They conclude that CA systems can improve maize yields in high rainfall areas but strategies are needed to mitigate waterlogging  after heavy rain and sustain soil fertility.

This research is conducted in the Mediterranean climate region of South Africa where the livestock sector constitutes a substantial contributor to the regional economy and where CA is integrated with livestock. Crop rotation with small grains and canola are combined with alfalfa and medics to supply feed for sheep. But this system raises concerns about livestock-crop competition but also nitrogen flows, on-farm nutrient balance, water pollution, soil acidification, biodiversity loss and impacts from climate change. This paper suggests that CA integrated agricultural systems serve as a buffer against environmental degradation caused by conventional agricultural systems.

This paper provides an overview of the science and farmers’ expectations of conservation tillage (CST) in six European countries, including Croatia, Serbia, Hungary, Slovakia, Czech Republic, and Poland where traditional intensive tillage results in soil erosion, loss of SOM, and soil degradation. This review looks at the adoption on CST in these countries and looks at the current progress and future prospects. CST provides adequate soil cover, minimizes erosion, and encourages biological activity and organic matter accumulation that results in improved soil productivity and resilience against additional degradation and climate variation. Results showed a high level of diversity in readiness and willingness to accept, as well as different levels of knowledge about the adoption of CST, but adoption is increasing and this represents a key way to slow soil degradation and adapt to climate change.

Wheat has seen remarkable productivity gains in NW India through increased input use and intensive cultivation. But soil degradation indicates that this essential food security region of India is becoming less economic and sustainable. This paper looks at data from 3928 wheat fields and used to assess multiple sustainability indicators including yield gaps N-use efficiency, profitability, and GHG emissions. Stochastic frontier analysis was combined with simulated potential yield (Yp) data to identify the causes of wheat yield gaps in the region The most important management practices governing the field classification included the crop establishment method used for the previous rice crop, the number of tillage operations, residue retention, and the N fertilizer rate for wheat.

This review explores a number of soil and water conservation practices, organic amendments, and agroforestry for specific soil types (7)  for the many diverse agroecological zones in Africa. In particular it looks at the role of soil through physical management to ensure resilience to climate change using long-term studies that are essential for improving soil structure, moisture retention, reducing erosion and enhancing SOM. However, adoption of these practices that improve resilience to climate change faces challenges due to diverse soils and ecologies, barriers to adoption and resource constraints. The authors advocate an integrated approach combining local expertise with scientific advancements and appropriate policy interventions.  to achieve the needed resilience.

This paper from Mexico looked at the the impact of conservation tillage (CT) versus intensive tillage (IT) on bacterial communities from experimental platforms that had practiced these three different tillage options for 25 years. The three tillage options were IT, CT and reduced tillage (RT) with residue with and without for each tillage practice. CT or conservation tillage showed higher species diversity and beta diversity while IT showed higher richness. IT results were grouped in the same phylum range whereas CT had a different range. CT also improved the soil physicochemical properties. Although not mentioned in the abstract, zero tillage and reduced tillage systems  led to the development of copiotrophic ecological niches, predominantly attributed to heightened organic matter levels stemming from the decomposition of agricultural residues and wastewater irrigation.

This review looks at several ways to improve soil physical health. They define this as physical, chemical and biological characteristics. It includes structure, porosity,  and water retention. They include  soil management like CA, cover crops, and organic amendments. They also suggested precision farming and remote sensing as ways to monitor and manage soil health. They found they had constraints to undertake this and so recommend that future efforts focus on multidisciplinary research to better understand complex relationships.

This paper quantifies the Ecosystem Services from 13 years of using CA practices in a maize-wheat system in India. The treatments were conventional tillage (CT), zero tillage with planting on flat land with residue (ZR + R), permanent broad beds with residue (PBB + R), permanent narrow beds with residue (PNB + R). The CA-based practices recorded higher value of provisioning ES values as compared to CT. The highest economic value of regulating ES was observed under PBB + R, which was 61% higher than that of CT. PBB + R is a better management alternative for better TES while ensuring higher crop productivity than CT. The results can be used to formulate the payment for ecosystem scheme by policy makers.

This paper looked at a strip-till one-pass machine that regulated and monitored sowing rate and depth while applying fertilizer. The objective was to assess the accuracy of this wheat drill. They found the accuracy was 97% and 92% in lab and field tests, respectively. Field germination was 88%. The authors conclude that their machine can facilitate planting wheat in accordance with CA needs.

This paper studies the effects of no-till (NT) and residue over the long- and short-term (24 and 3 years) in a semi-arid area of Mexico in a maize-oat-triticale system established in 1995. There were 6 treatments: plow+harrow (PH), harrow (H), multi-plow (MP), No-till (NT), NT with 33% residue, and NT with 66% residue. Soil quality was increased with NT + R by increasing SOM but also total carbon and enhanced microbial abundance. Tillage treatments, however led to lower SOM and lower yields. Differences were also visible soon after the experiment was initiated.

This paper from Uganda looks at the adoption of sustainable agricultural intensification practices (SAIPs) recommended for smallholder farmers.320 maize farmers were interviewed in 2 Districts. Results showed that improved maize varieties, conservation tillage, legume intercrop, integrated soil fertility management (ISFM), and integrated pest management (IPM) were adopted by 58, 36, 44, 52, and 56% of the farmers. Institutional factors were significant predictors of adoption. Socioeconomic factors only positively influenced adoption intensity for SAIPs. Two policy recommendations were to strengthen agricultural extension and promote the use of village level credit services to enhance adoption.

This is an interesting article that looks at adding no-till potatoes after rice in the Sundarbans of West Bengal, India. The no-till potatoes is diagrammed in this paper and consists of applying a 10cm layer of compost on the soil surface, planting the potato tubers on this compost and then covering the tubers with 20 cm of paddy straw as a mulch. This area after rice is normally left fallow. This experiment was conducted over 8 years to intensify cropping systems and improve farmer incomes. The first 2 years was used to identify suitable potato germplasm. This cropping expansion improved soil health, conserved moisture and reduced labor and costs. The analysis of the estimated adoption also showed that more than 90% adoption is likely to be achieved within a decade.

This paper looks at the success of CA in high rainfall areas of Northern Zambia from a long term (9 year) experiment to determine if CA is a viable system under these conditions. The experiment looked at three different CA systems, basins, animal ripped line planting, and dibble stick planting and compared with conventional inversion tillage and ridge and furrow tillage. Yearly rainfall over these 9 years was variable. The 3 CA systems mostly did better than the 2 conventional systems, especially in medium to low rainfall years. But ridge and furrow systems did better in high rainfall years because of better drainage, but overtime, yields declined because of nutrient decline. They conclude that CA systems can be recommended in these high rainfall areas in management systems to overome waterlogging and sustain soil fertility are included.

This paper looked at longterm soil ecosystem status of farmers adopting CA under two different management and environmental conditions in Southern Africa using conventional systems and grazed grasslands as checks. Various soil chemical, physical and biological properties were measured. At one of the sites pasture and conservation agriculture systems presented elevated organic matter content and microbial activity due to continuous organic cover and minimal physical disturbance and essentially healthier soils. In the second site differences between conservation agriculture systems were strongly associated with soil texture differences, influencing organic matter and respiration rates. This means that tailored systems to complement on-farm options and local conditions are needed.

This paper on Africa highlights and discusses the current problems which include soil erosion, desertification, nutrient imbalances, acidity, salinization, deforestation, and soil compaction. The second part looks at the problems of soil and agricultural productivity and  human health, which resulted in loss of fertile land and biodiversity, increased greenhouse gas (GHG) emissions, nutrient depletion, loss of ecosystem services, malnutrition, and other human health issues. The third part proffers potential solutions to tackle soil degradation in Africa. They conclude that iintegrated approaches that promote sustainable soil management, such as conservation agriculture, crop rotation, agroforestry, afforestation, organic farming, and community engagement, would have a significant impact in resolving the menace of soil degradation.

This study examined types of adaptation strategies implemented by males/male-headed households and females/female-headed households and how these influence food security.They used a household food insecurity Access Prevalence (HFIAP) and a probit model to assess food security and adaptation strategies. They collected data from 521 household in Kenya and 1,049 adults. Many of these respondents mentioned reduced and less predictable rainfall resulting in longer droughts that affected productivity. The respondents used three adaptation strategies to  address the above problems: CA (69%), changes in planting dates (49%) and planting drought tolerant crops and varieties (47%). More male dominated households that female used all 3 strategies. Access to credit, non-farm income, types of crops grown, and weather perception variables were the important determinants of adaptation. They conclude that the three strategies worked to increase food security for male dominated households but not female dominated households who are more susceptible to climate change and suggest policies are needed to help female headed families.

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 uses the term "incorporated" for residues in CA but not sure if they mean surface applied or incorporated into the soil. I think they mean used as surface residue. They looked at GHG emissions using different amounts of nitrogen. They collected soil samples from fields after 6 years of 0, 187 and 337 kgN/ha; low, medium and high N. Straw was with and without. Adding straw significantly increased N20 and C02 emissions compared to those with out straw. Medium N had lower N2) emissions compared to high N and increased C02 emissions compared to 0N with straw. In conclusion, straw amendment increased GHGs and diminished the risk of losing mineral N by enhancing its turnover. Straw with medium-N soil could mitigate the greenhouse effect and improve the N and carbon (C) balance in farming systems compared to low- and high-N soils.