Fertilizer Requirements of Yam (Dioscorea Rotundata) In Nsukka Acid Sandy Soils

Abstract

Nitrogen, Phosphorus and Potassium were applied to yam in 33 field trials on three soil types in Nsukka over two years. Quadratic response surfaces were fitted to the tuber yield data and where appropriate optimum and economic levels of the nutrients were estimated Ln the sandy clay loam there were positive responses only to nitrogen 'but in the loamy sand responses to .all the nutrients were obtained. The requirements of the three nutrients in the loamy sand for most economic returns were 49 kg N, 115 kg P20 S and 38 kg K20 per hectare resulting to a fertilizer recommendation on for yam of 10: 25 : 8 at 500 kg per hectare.