Nitrogen source fertilization for nutrient profiling of Royal Delicious apples in temperate ecosystem

The investigations were conducted at Denwari, Rohru in Shimla district, Himachal Pradesh to compare the effects of various sources of nitrogen on leaf and soil nutrient status of Royal Delicious apple and to find out an alternate source of nitrogen for the substitution for CAN (calcium ammonium nitrate) which was recommended for Himachal Pradesh. Soil application of five sources of N viz urea, calcium nitrate, NPK (19: 19: 19) + urea, NPK (12: 32: 16) + urea and calcium ammonium nitrate at the three levels (840, 700 and 560 g N/tree) was tried and compared to get best nitrogen source and level of application. The results indicated that highest leaf N content was recorded with the treatment of urea at 840 g N/tree whereas highest P and K contents were recorded with NPK (19: 19: 19) + urea at 560 g N/tree. Leaf Ca, Mg and micronutrients viz Fe, Cu, Zn and Mn concentrations were also quantified significantly by different soil N fertilization in similar trend. Soil pH decreased with combination treatment of NPK (12: 32: 16) + urea. However organic carbon and soil N, Fe, Cu and Mn increased with urea and soil P and K increased with NPK (12: 32: 16) + urea and calcium ammonium nitrate respectively.