Abstract

In order to develop the relationship between soil test and response of lentil to applied fertilizers under Integrated Plant Nutrition System (STCR-IPNS), a field experiment was conducted on Aquic Hapludoll of Uttarakhand during Rabi 2009-10 following Ramamoorthy’s targeted yield model. Using the data on grain yield, initial soil test values on available NPK, doses of fertilizers and farm yard manure (FYM) applied and NPK uptake, the basic parameters viz., nutrient requirement, contribution from soil, fertilizers and FYM were computed. It was found that 5.24, 0.72 and 3.58 kg of N, P and K respectively were required for producing one quintal of grain. The percent contribution of nutrients from soil, fertilizer and FYM were 32.01, 43.02 and 11.02 for N; 30.0, 32.03 and 8.04 for P; 31.06, 42.01 and 9.00 for K respectively. Making use of these basic parameters, fertilizer prescription equations were developed for lentil (var. PL-5) and an estimate of fertilizer doses were formulated for a range of soil test values and desired yield targets under NPK alone and IPNS (NPK plus FYM). Coefficient of determination (R2) was significant (0.805 **) between yield and soil test values. Verification trial was also conducted to test the validity of fertilizer prescription equations in next season i.e. Rabi 2010- 11. The variation in yield obtained from targeted yield ranged from -5.0 to +1.9 %.The farmer’s practice of fertilizer application was least efficient to produce grain yield of lentil in comparison to other treatments. Highest response ratio was found with farm yard manure 10 t ha-1+ yield target 16 q ha-1.

Keywords: Fertilizer prescription equations, integrated plant nutrition system, Lentil, Soil test crop response, yield target, Mollisol.