Smallholder farmers in Africa under semi-arid conditions grapple with harsh conditions that undermines productivity: as well as soil the scarce rainfall water is increasingly lost due to runoff. It is estimated that over 50% of rainwater is lost by surface runoff and evaporation, with only 15-30% retained by the soil. This retained water is insufficient for crop production, and this challenge has increased food insecurity because of the failure of perennial crops; for example, in Marange, maize yields have fallen as low as 0.4 tons per hectare: more than three times lower than the national average (1.39 t/ha).
Farmers in Marange have tried various adaptation strategies such as infield water harvesting, changing planting dates, using alternative crops, and testing improved seeds. However, these practices alone have not resulted in significant increases in crop productivity. In the face of extreme weather events and climate crisis, enhancing the capacity of smallholder farmers to improve soil health and make the most of scarce rainfall is essential to increase the resilience and absorptive capacity of vulnerable communities.
Implementing a combination of practices for water capture and soil health improvements could be a solution to these challenges, helping to transform the productivity of farms in low rainfall areas. How can farmers be motivated to try this approach? The most convincing method is through seeing the success story of a neighbor, and here is where the farm of Sadreck Maocha – a local farming champion in Marange – is making a difference.
A partnership between the Swedish University of Agricultural Sciences (SLU) the Bindura University of Science Education (BUSE), the Alliance of Bioversity International and CIAT and Michigan State University (MSU) has conducted on-farm experimentation of different climate-smart agriculture options in Zimbabwe since 2019, and Mr. Maocha was one of the most eager early adopters.
His farm is located at the edge of a rock catchment, providing an opportunity to direct all the runoff water through runoff channels and ditches, supporting groundwater recharge. To avail runoff water from the rock catchment, a number of systems were implemented, including the diversion of runoff water into the field through contour channels, the installation of cross-ties along contour channel, the fortification of contour channels with infiltration pits, and the use of in-field water harvesting techniques such as ridging and sub-surface waternets. To improve soil health, different techniques were adopted such as intercropping, mixed cropping, the use of organic manures, the 4R principles of nutrient stewardship (right source, right rate, right time and right place), as well as integrated soil fertility management by mixing organic manures with reduced inorganic fertilizers to improve farming outcomes.