Smallholder farmers' knowledge on the use of bioslurry as a soil fertility amendment input for potato production in Kenya

A survey was conducted on farmers' fields at Werugha and Wusi‐Kishamba wards in Taita Taveta County, Kenya, to assess the factors influencing farmers' decisions on the use of bioslurry in the management of soil fertility. Knowledge gaps on bioslurry use provide contrasting claims about the value of bioslurry from source, storage and handling, crop types, soil, and climate conditions, and as a fertilizer. The majority of the farmers in the study sites double up as dairy farmers which has resulted in enormous production of under‐utilized cow dung. Over‐dependence on the use of inorganic fertilizers leads to the destruction of soil physical and biological properties; hence, the provision of essential nutrients required by plants for growth and development is not achieved at the maximum recommended rates. This results in a yield decrease with potato yield ranging from 8 to 15 t ha−1, which is 2‐ to 3‐times below the achievable yield of 40 t ha−1. A survey questionnaire was developed and administered to 120 small‐scale farmers within the two wards. Results showed that the use of bioslurry has not been well adopted by farmers from the two wards as only 18% responded to using bioslurry on their farms whereas 78% relied on chemical fertilizers and other forms of manures such as farmyard manure. However, even those using slurry had since been reported to have challenges with its use and application. The 36% of farmers who applied bioslurry alone did so due to its availability considering the high cost of inorganic fertilizers while those who combined it with inorganic fertilizers had faith in chemical fertilizers and that they aimed at achieving high crop yields. The major challenges farmers faced while using slurry on their farms were reported to be on lack of knowledge on the exact quantity to be applied per unit area and on the storage of excess slurry from biodigesters. This implied that even though slurry was available, it was still not useful to the farmers due to under/over application and poor storage. The study, therefore, recommends capacity‐building programs and agricultural extension services to be developed, to ensure adequate knowledge on bioslurry use and adoption by smallholder farmers in the management of soil fertility in enhancing crop productivity.