Influence of long-term fertilizer application on soil properties and leaf nutrient concentration in mango (Mangifera indica).
Raghupathi H. B., Reddy Y. T. N., Kurian R. M.
Author Affiliation: Indian Institute of Horticultural Research, Bangalore, Karnataka 560 089, India.
Indian Journal of Agricultural Sciences 74 : 351-354
Abstract : The variations in soil properties and nutrient concentrations in leaf as influenced by application of: 0, 10, 25, 50, 100, 150, 200 or 400 g N; 0, 2.15, 4.30, 8.60, 21.50 or 43.0 g P; and 0, 8.30, 16.60, 24.90, 83.0 or 166.0 g K/plant per year of age, stabilized after 10 years, was studied in Totapuri mango (Mangifera indica). Three field trials were conducted in Bangalore, Karnataka, India which were under the above treatments for 15 years. The available N showed no significant changes due to N application at different rates. The available S concentration increased by nearly 3-fold (28.3 to 67.2 ppm) and that of Fe by 8-fold (23.1 to 182.0 ppm) when N application was increased from 0 to 400 g/plant per year of age. Only available Fe was significantly affected due to application of P at different rates. Application of K affected the electrical conductivity, available K, Mg and Fe status in soil in the long run. The electrical conductivity increased by nearly 2-fold and available K from 187 ppm to 1414 ppm due to K application. The available Mg (108.0 ppm) and Fe (44.5 ppm) levels were significantly lower at higher levels (166 g K/plant per year) of K application. None of the leaf nutrients except that of Ca showed any significant difference between high- and low-yielding plants due to N application. Both P and K application resulted in higher concentrations of N, Ca and Mn in the leaves of high-yielding plants. The application N, P or K resulted in imbalance of leaf Mg (0.24 to 0.29%) and Zn (16.1 to 18.2 ppm), notwithstanding presence of adequate available Mg and Zn in soil, which was not a consequence of increased yield potential, as the differences in their concentration between high- and low-yielding plants were marginal. The long term application of K resulted in greater imbalance of the nutrients compared to the application of N or P. No significant build up in N, P or K concentration in leaf was noticed in high-yielding plants.