Matching nutrient balances with local knowledge to improve productivity of semiarid areas of Kenya.

This paper presents a study examining erosion. In all cases analysed net farm itrogen, phosphorus, potassium and organic income was negative for crops grown under arbon dynamics using the nutrient rainfed conditions and positive for crops nonitoring (NUTMON) model approach for grown under irrigation. On average 4 kg/ha lssessing nutrient flows, stocks and their ofN as mineral fertilizer was applied to the :ffects on economic performance of typical farms, 5 kg/ha N in the form of animal 'arms in semi-arid areas in Kenya. Soil manure, 7 kg N/ha in animal faeces and ;ampling was carried out to determine total urine during grazing. Farmers were able to Ij, P, K and carbon concentration within the identify soil nutrient deficiencies, formulate top 20cm of the soil layer. Systematic in conjunction with researchers remedial collection of information on farm measures and priority areas of intervention management practices using structured in rainfed and irrigated systems. questionnaires allowed quantification of Implementation of the designed trials was flows of materials with emphasis on soil through farmer managed on farm trials nutrient balances and cash flows. Soil carried out through the participatory learning nutrient content was followed by the same and action research approach. Treatments feedback sessions to the farmers on balance combining 5 t/ha farmyard manure (FYM) flows and main nutrient deficiencies. This and 60kg N/ha DAP fertilizer under irrigation led to formulation of a research agenda to yielded 3.6 t/ha maize grain and 9.4 t/ha address nutrient constraints during the stover. With farmerpnfctice (d"l t/ha FYM) experimental design workshop. Farmers and yielding 2.8 t/ha grain and 6.5 t/ha stover. researchers soil characteristics matched Maize grown under rainfed conditions with well as far as indicators of poor soil fertility 5 t/ha FYM and 60kg N/ha fertilizer mdicators are concerned. Although farmers combinations yielded 1.5t/ha grain and 3.9 associate poor crop yield with poor soil t/ha stover compared with farmer practice nutrient status, relations between differences 0.5 t/ha grain and 3.1 t/ha stover. Maize of individual nutrients and deficiency grown with 5t/ha FYM and 60kg N/ha in symptoms were not explicitised by the irrigated system had a positive gross margin farmers. Averaged for all farms sampled, . However, maize grown under rainfed negative partial balances were found for N, conditions had negative gross margins P, K and organic carbon. The losses in the compared to other treatments. However, the current economic environment where producer price of maize is low and fertilizer cost is high, there is no incentive for soil fertility improvement (use of fertilizer)under rainfed conditions.