Conservation Agriculture Research Updates - March 2026

This study in Finland looked at soil physical, chemical and biological properties, erosion and carbon allocation to soil physical fractions between CT and NT at a clay soil site after 10 years. After 10 years various soil properties and earthworm total density, mass and species richness were determined. Total soil erosion was 56 % less in NT than in CT although surface water discharge was higher in NT. NT had a clear effect on the topsoil physical structure by decreasing the pore size and increasing soil aggregate size. This paper didn't mention residue management. The results showed that NT is an effective method to reduce erosion rates but other means to increase carbon input especially below the topsoil layer are likely required to achieve a significant increase in the carbon stock of boreal clay soils.

This study aimed at analyzing runoff and soil erosion in a non-tilled field in comparison with a tilled field during the transition period from CT to CA in Italy. Runoff water volume was measured at each rainfall event, and the amount of sediment was quantified by drying the runoff samples. Two indices, runoff reduction benefits (RRB) and sediment reduction benefits (SRB), were computed. NT practices resulted in reductions of over 50% in runoff volumes and 50% to 95% in sediment losses. The average sediment concentration in NT was only 47% of CT. It would have been interesting to add with and without residue to see if this made a difference.

This paper was chosen to show CA is viable for organic vegetable systems. Organic vegetable farmers are often dependent on tillage to incorporate crop residue, control weeds, and prepare seedbeds. Black, impermeable, polyethylene tarps applied on the soil surface and removed at planting can help suppress weeds before planting and reduce farmers' reliance on tillage. This study investigated the effects of tarp use and tarp duration on the soil environment, surface cover crop residue, and weed suppression to assess the efficacy of using tarps to improve reduced- and no-till practices for organic vegetable production in the US. They conclude that using tarps facilitates reduced and zero-till vegetables by providing a nutrient-rich and moist soil environment free of emerged weeds before planting without soil disturbance.

Challenges that have arisen with the adoption of NT include soil compaction, weed management, and stratification of organic matter and nutrients. As an attempt to overcome these challenges, occasional tillage (OT) has been used as a soil management practice in NT systems. The objectives of this meta-analysis were: 1) to summarize the effects of OT on crop productivity, soil physical, chemical and biological properties, soil erosion and weed control; 2) to discuss the main aspects of NT management to optimize the use of OT; 3) to point out shortcomings in the diagnosis of soil compaction in NT systems, which may lead to erroneous decision-making processes regarding the use of OT. They conclude that proper NT implementation and management, with the correct application of NT principles, will overcome problems associated with NT. As soil compaction is the main justification for the use of OT, methods of diagnosis and monitoring of soil compaction should be improved to assist in decision-making.

This study looks at the feasibility of using "Agrimats" - mulching materials that are manufactured using cheap or freely available organic waste materials including forestry waste and grasses that allow a permanent soil cover. This study aims to advocate permanent soil cover using agrimat as an innovative pro-smallholder farmer technology to improve soil quality for better food security.

Issues of decline in groundwater levels, urbanization of agricultural land and the growing population and climate change all threaten food security in South Asia. The objective of this review was to deliberate the causes of soil degradation in South Asia and suggest soil management options to reverse the degradation trends and ensure long-term food security in the region. One important point this paper makes is better communication and collaboration between scientists, farmers, and policymakers is needed to manage soils to ensure food security in South Asia. 

This is an interesting paper from Spain. Other mammals could be creating similar issues in other countries. This study looked at CA and different crops in relation to vole population. Their results show that tillage practices have more influence on common vole occurrence (zero tillage > reduced and conventional tillage) than other aspects such as crop type thus supporting the hypothesis that tillage practices play a key role in common vole habitat use.

This paper provides information to society and decision-makers about the effectiveness of of conservation agriculture (CA) principles with zero tillage (ZT/CA) and integrated crop–livestock–forest (iCLF-CA) systems as central policies to mitigate soil erosion, the main agent of land degradation and productivity loss in Brazil. The annual potential for soil erosion with intensive conventional tillage and monocropping, considering land use and cover in 2017, is 3.0 billion tons. The economic impact, based only on replacement of nutrient losses, is estimated to be 15.7 billion US$ yr−1. The annual economic impact of the adoption of CA principles by controlling soil erosion was estimated at 1.5 billion US$ for ZT/CA in 2017 and 0.5 billion US$ for iCLF-CA in 2015. They conclude that the positive impacts of the adoption of CA principles in Brazil are the result of the determination of farmers, among many actors, and of the effectiveness of government plans and policies.

This 16 year long term study in Hungary looked at the effect of conservation tillage (CT) on run-off, soil loss and soil in large plots and compared with ploughing tillage (PT). By the end of the study period, significantly higher water-stable aggregates (PT: 20.0 %, CT: 30.4 %), higher soil organic matter (PT: 1.4 %, CT: 1.9 %), greater earthworm abundance (4.9 times that in PT plots) was recorded on the CT plots. The difference between PT and CT was significant for mean annual soil erosion, with values of 2.8 t ha−1 and 0.2 t ha-1, respectively. They conclude that the use of CT enabled the maintenance of a major fraction of precipitation on arable land, and consequently, soil loss remained an order of magnitude lower than its tolerable value.

This study, in Central Malawi considered to have a relatively high uptake of CA, uses analyses of satellite images, field observations, interviews with farmers, extension workers and other people involved in CA promotion, as well as a household survey, to investigate how CA has been adapted. They found that continuous minimum tillage (no ridging), ground cover and crop rotation/intercropping were not practiced as intended. One-third of non-ridged land was tilled during the growing season, and half was again ridged in the following season. Unless crop residues were added, the soil’s surface of non-ridged plots was usually bare at planting, causing weed control problems, and an increased risk of erosion. Most farmers added large volumes of crop residues to their non-ridged plots. They collected these from the surrounding fields, but this practice severely restricted the size of these plots. Crop rotation/intercropping was practiced less when farmers stopped ridging. Very few farmers practiced all three CA principles simultaneously. CA promotion appeared to only increase yields on plots where mulch was added. What was not discussed were suggestions for alternate ways than CA to address the issue of soil degradation -- nutrient mining, erosion and compaction.  Also, in this area where ridging is common, CA can be applied to these beds by keeping the beds permanent (just reforming each season) and applying residue available in-situ or from other sources on top of the beds. The last sentence of this paper also suggested growing groundnuts. This is unlikely to address issues of land degradation but would be a important as an intercrop with maize on permanent beds.

This is a link to Chapter 11 of the book entitled "Rethinking Food and Agriculture" mentioned in the Scoopit newsletter. This renowned soil scientist looks at CA as a way to reverse soil degradation as a result of erosion, loss of soil organic matter, pH changes and disruption of soil life resulting from conventional agricultural practices including tillage. He suggests that CA can help reverse the problem of soil degradation that has plagued societies throughout history. Doing so would contribute to addressing the problems of sustainably feeding the world, increasing soil-based carbon sequestration, and reducing off-farm water pollution.

This paper explores the effectiveness of high-resolution topography in characterizing no-tillage (NT) versus conventional tillage (T) surface morphology in order to better understand the hydro-geomorphic processes associated with these crop systems in a clay loam soil in Italy. Surfaces in the NT plots were rougher, had more pronounced slopes and curvatures, sediments with a widespread connection to the plot boundaries, had more irregular flow paths, and had a higher water storage potential due to surface concavities. The NT surface morphology significantly reduces surface runoff, sediment transport, and the off-site movement of agricultural chemicals.

This review documents the current knowledge of ecosystem services for key management practices based on experiences from agricultural lands in sub-Sahara Africa (SSA). Here, practicing conservation agriculture (CA) and Integrated Soil fertility management (ISFM) have overall positive benefits on increasing infiltration (>44), reducing runoff (>30%) and soil erosion (>33%) and increases soil biodiversity. This summary of key considerations for evaluating practices from multiple perspectives including provisioning, regulating, supporting and cultural ecosystem services is important to inform future soil health policy and research initiatives in SSA.

This paper looks at tillage, crop residue and N-management in the high-slope mountains of Ecuador where high rainfall causes significant soil erosion. In the initial phase 3 out of the 4 crops NT had the highest yields. Later, with addition of N fertilizer, yields were higher in 4 out of 5 crops not fertilized. Leaving the crop residue on the surface increased the yield of one crop. Higher net returns were found with NT compared to tillage.