An evaluation of nutritional constraints on irrigated rice yield
Nutritional constraints often restrict yields of field crops in farmers’ fields. The present study aimed to determine minimum rice yield target of high-yielding subpopulation in farmers’ fields and nutritional difference between high and low yielding subpopulation. Popular high yielding rice (variety BRRI dhan28) was grown in 42 farmers’ participatory nutrient management trials with two treatments – farmers’ nutrient management plan (FP) and improved nutrient management plan (INM). Nutrient composition was determined from Y-leaf after 45 – 50 days of transplanting. Yield cutoff value between low and high yield subpopulation was determined from compositional nutrient diagnosis (CND) generic model. The CND generic model gave 6.90 Mg ha – 1 as minimum cutoff yield of the high-yield subpopulation. Potassium was identified as the main yield limiting nutrient for rice in piedmont soils. Irrigated rice in farmers’ fields of Asia may require higher K fertilizer dose for better yield.