In Zimbabwe, an estimated 75%-90% of crops remain unfertilised each season and when used, farmers on average only apply 3kg of nitrogen fertiliser per hectare, compared to average rates of 9kg per hectare for all of sub-Saharan Africa. The usage rates are low and variable due to limited knowledge of appropriate use, lack of availability and affordability as well as cultural and traditional beliefs that fertilisers ‘burn’ the crops.
Since 2004, the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) has been working in partnership with the UK Department for International Development (DFID), the national extension service and NGO’s to promote conservation agriculture amongst smallholder farmers. Conservation agriculture consists of 3 principles: minimum soil disturbance, legume-based intercropping and application of organic mulch to improve soil fertility. In 2011, more than 150,000 smallholders practiced conservation agriculture, raising cereal yields 15% to 100% across different regions. When combined with microdosing – the precise application of small amounts of fertiliser that smallholders are likely to be able to afford – farmers in Zimbabwe significantly improved household food security.
To increase the adoption of fertiliser use, ICRISAT provided training on microdosing for more than 650 lead farmers, 241 government extension officers and 119 extension officers from 16 local and international NGOs. From 2003-2007, more than 160,000 households received 25kg bags of nitrogen fertiliser and flyers in local languages explaining how to apply the fertiliser. Despite poorer than average rainfall during the 2006/2007 cropping season, farmers experienced yield increases between 30% and 50%. During the same season, more than 170,000 households increased cereal production by an estimated 40,000 tonnes, saving US$7 million in annual food imports and significantly improving food security. As of February 2013, close to 300,000 farmers are now using both technologies and have achieved productivity gains of up to 100%. Nevertheless, challenges to adoption still remain; the programme is therefore trialling smaller packs of fertiliser between 5g-20g as well as trying to reduce the labour constraints to adopting all 3 tenets of conservation agriculture.