DRIS indices as nutritional guide for aonla cultivation

Diagnosis and recommendation integrated system (DRIS) norms were computed from the data on leaf mineral composition, soil available nutrients, and corresponding mean fruit yield of 100 aonla orchards in Akhnoor, Raya and Purmandal areas of Jammu region during 2016 and 2017. The DRIS norms derived primarily from leaves suggested optimum leaf macronutrient concentration as 1.74-2.96% nitrogen (N), 0.13-0.23% phosphorus (P), 0.73-1.04% potassium (K), 0.18-0.27% sulphur (S), 1.72-1.93% calcium (Ca) and 0.35-0.55% magnesium (Mg) while, the optimum level of micronutrients as 9.34-11.93 ppm zinc (Zn), 89.24-156.98 ppm iron (Fe), 7.24-10.42 ppm copper (Cu) and 8.97-21.64 ppm manganese (Mn) in relation to fruit yield of 16.55-114.24kg/ tree. Likewise, DRIS indices for soil fertility developed from soil samples collected at 0-30 cm depth corresponding to similar level of fruit yield, the optimum limit of soil available nutrients (mg kg⁻¹) was observed as 109.44-442.78 kg/ ha N, 8.84-15.46 kg/ha P, 93.17-199.15 kg/ha K, 6.79-11.42 mg/kg S, 0.35-4.36 mg/kg Zn, 2.81-13.42 mg/kg Fe, 1.44-4.43 mg/kg Cu and 0.28-2.84 mg/kg Mn. Primary DRIS indices developed on the basis of leaf revealed K as deficient in 55 per cent of the orchards followed by N in 25 per cent and Ca and Mg in 15 and 5 per cent, respectively, whereas Mg was identified as excess in 45 per cent orchards followed by N, P, K and Ca.