Targeted yield approach for optimizing the fertilizer prescriptions for chickpea

To establish the relationship between soil tests and response of chickpea to applied fertilizers, a field experiment was conducted during 2003-2004 following Ramamoorthy's targeted yield approach on Aquic Hapludoll soils of Uttarakhand. Using the data on grain yield, initial soil test values, applied fertilizer doses and nutrient uptake, the basic parameters viz., nutrient requirement, contribution from soil and fertilizers were computed. It was found that nutrient requirement for production of one quintal of chickpea was 4.91, 0.63 and 3.27 kg N, P and K, respectively. Efficiency of soil nutrient was 25.54, 41.73 and 19.71% while that of fertilizer 114.23, 15.38 and 109.08% for N, P and K respectively. Making use of these basic parameters, fertilizer prescription equations were developed for chickpea (var. Radhey) and an estimate of fertilizer doses was formulated for a range of soil test values and desired yield targets. It was observed that fertilizer rates increased as yield targets of chickpea increased while its rates decreased as the initial soil test level increased.