Increasing the adoption of nutrient management innovations by Cambodian vegetable farmers

Vegetable production in Cambodia is largely constrained by access to fertilizer and water. Given that the humid tropical soils of Cambodia are highly weathered, crop nutrient availability tends to be relatively low. Soil amendments such as cattle manure, farmyard compost, and locally available fertilizers are applied in limited amounts to improve soil properties, but mineral fertilizers are usually not affordable by subsistence-oriented farmers, leading to widespread nutrient deficiency in smallholder vegetable crop production. Farmers often attempt to supplement the available nutrients in the soil by applying manure, but household manure availability varies greatly depending on the magnitude of livestock integration in the local production systems. Therefore, manure applications often do not meet plant nutrient demands. This loss in productivity, combined with reduced access to available resources and technology, subsequently exacerbates the food insecurity of rural smallholder farmers. Farmers often feel uncertain about how much manure and/or mineral fertilizers to apply in order to maximize yield and profitability. Inappropriate nutrient management often results in low yield and poor nutritional quality of the vegetables produced and inversely can have negative environmental consequences. Therefore, proper nutrient management practices are essential for Cambodian vegetable farmers to ensure the successful production of quality vegetables. Several fertilizer recommendations for horticultural production currently exist; however, adoption has remained low, and fertilizer under and over supply is common. There is need for the incorporation of bidirectional learning in the research and dissemination pathway that allows farmers to experiment with new fertilizer recommendation innovations and that learns from farmer feedback to adapt the innovation to better match their needs.