Conservation Agriculture Research Updates - April 2026

This research from Uganda looks at nitrogen fixation with pigeon peas in a maize dominant cropping pattern to investigate the effect of biochar under CA on nitrogen fixation at three sites located in different agro-ecological zones. CA involved minimum tillage with planting basins established by hand hoeing. There were 4 treatments: (1) conventional tillage with crop rotation (CT), (2) minimum tillage with crop rotation (CA), (3) CA and plus biochar, applied in both first and second year (CA+BC+BC), and (4) CA and biochar, applied once in the first year (CA+BC). Grain yield was significantly increased by biochar application in CA systems compared to conventional practices, in all seasons and sites. They conclude that "Biological N2-fixation was positively influenced by biochar application under CA systems". 

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 paper evaluated CA as practiced by farmers and compared farmer understanding of soil health in three East African countries. CA and non-CA fields were compared by sampling for 2-3 years. CA and non-CA fields were located close, on soils with the same texture, growing similar crops. Most of the CA fields were planted in basins. Farmers and technicians collected the data together. Farmers said that CA improved hoe-ability, crusting, smell and water infiltration. Fields under the CA treatment had a higher probability of rating better than non-CA fields. The paper discusses both benefits and drawbacks of using participatory, on-farm research. They conclude that farmer participation as citizen scientists will advance soil restoration in East Africa and increase the potential for farmer-to-farmer knowledge exchange of soil-improving practices.

This paper used 761 household interviews and 33 focus group discussions with smallholder farmers in Zambia on how female and male farmers see CA helping with climate change. Results show that men and women farmers had similar experiences of climate change, namely late onset of a shortened rainy season, intra-seasonal drought and higher temperatures. The study concludes that there is room for CA to serve as a climate smart agricultural system for both men and women smallholder farmers in Eastern Zambia. However, this will require addressing important challenges of high weed pressure, high labor demands, and low access to manure, and CA farming implements. 

Increasing climate variability is affecting  smallholder farmers in southern Africa. This study looks at Conservation Agriculture (CA) as a way to improve the resilience of farming systems against the adversities of climate, specifically moisture stress.CA and CT practices are assessed over a 14 year trial period on soil moisture and infiltration rates in Zambia. Soil chemical properties were also evaluated for these two tillage systems. Results showed significant differences in average soil moisture in the first 60 cm among the cropping systems in different years with the basins plus mulching system having highest moisture content in most of the years. Water infiltration rates were highest and averaged 48.5 mm h−1 in the CA-based systems and the lowest in CT which averaged 12.6 mm h−1. Soil chemical properties did not differ across tillage systems. The increased infiltration and available moisture in CA systems can buffer the effects of climate variability and provide greater resilience.

This study used the results from 638 farms representing 3 ago-ecological regions in Mozambique. Net returns and risk were generated for various CA technologies. The results suggest maize yields were higher for CA systems compared to CT and also less variable. At higher elevations, direct seeding was risk-preferred compared to CT. At lower elevations, results were ambiguous and CT may be better than CA. They conclude that selecting areas for CA that are known to do well is needed before out-scaling technology transfer.

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.

Despite the introduction of CA to Southern Africa 3 decades ago, adoption has been low. This paper attempts to assess the effects of risk and impatience on the extent and intensity of adoption of CA in Zambia. Data was obtained from 646 households. 12% and 18% of the the smallholder respondents were impatient and risk averse, respectively. The paper discusses the reasons for these problems. They conclude that there is a need to include risk management, like crop insurance, when scaling sustainable agricultural practices to accelerate adoption.

This paper from a sub-humid area of Uganda looks at ways to conserve water and increase water use efficiency (WUE) in rainfed areas to overcome issues of unreliable rainfall and high evapotranspiration during critical growth stages. They evaluated different climate smart agriculture (CSA) practices, such as mulching and permanent planting basins (PPB), on maize growth, yield, water use efficiency and soil moisture storage. They showed that maize biomass significantly increased under the tested CSA practices in the study area. Permanent planting basins increased maize grain yield (11-66%) and water use efficiency (33-94%) compared to the conventional practice. Mulching also increased yield and WUE relative to the control and significantly increased soil moisture storage compared to PPB and the the control without mulch.

This paper was given at the 1st International conference on Sustainable Land Management in Indonesia. This paper looks at the impact of CA in a semi-arid area of Indonesia. All the farmers in this project say that CA increased maize productivity and some farmers were even able to plant two maize crops with good yield in a drought year. Integrating forage into CA based farming also enabled farmers to provide enough feed 1-2 cattle per household. In this area basins were dug and then CA used. Labor was an issue but I suggest they make these basins permanent to lessen labor in the second crop/year. The residue mulch is also needed for animal feed. Similar to other dryland areas.

This paper looks at access to animal drawn CA planting machinery to reduce the burden farmers complain about digging basins for CA in Zimbabwe. They used a 5A's framework of access: acceptability, accessibility, affordability, awareness and availability. Data was collected from households using focus group discussions, key informant interviews and personal observations. They recommended monetary incentives to farmers practicing conservation agriculture. Such incentives have to be based on amount of carbon sequestered and should solely be used for the purchase of conservation agriculture equipment.

This study looks at the effect of tillage and crop rotation (CA vs CT) on macro-organisms in Zambia on a LT trial. They looked at CT, basins, direct sowing plus sole cropping, two or three year crop rotations involving maize, cotton and sunnhemp. The data looked at earthworms, termites, dung beetles and centipedes. Biota diversity was generally higher in CA compared to CT treatments. They found that reduced tillage systems and crop rotations increase biological activity compared to CT systems.