Fertilizer Prescriptions on Soil Test Basis for Jute, Rice and Wheat in a Typic Ustochrept

Field experiments were conducted with different fertility gradients in Gangetic alluvial soil (Typic Ustochrept), Nilgary series. The soil was low in N, low to very high in P and medium in K having pH in the neutral region. Illite was the dominant mineral with CEC of the soils ranging from 17 to 26 cmol (p⁺) kg⁻¹. Basic data of jute, rice and wheat were evaluated on nutrient requirement for one quintal fibre/grain production, per cent contribution of nutrients from soil and fertilizer sources. Targetted yield equations were generated for individual crop under jute-based cropping system. Yield targets were attained for jute (cv. JRO 7835) 25 to 30 q ha⁻¹, coarse rice (cv. Pankaj) 35 to 50 q ha⁻¹ and wheat (cv. Sonalika) 30 to 35 q ha⁻¹ with ±10% variation from the desired yield targets. Validity of the yield targets was tested at farmers' fields through follow-up trials as frontline demonstrations which revealed that prescription-based fertilizer application on testing of soils was found profitable as compared to ad hoc recommendation. Phosphorus application to jute could be skipped off in soils having available P above 10.5 kg ha⁻¹ evaluated as critical limit.