Leaf litter addition and nutrient recycling in rubber in Vellanikkara estate

Abstract

Preliminary studies on the total quantity of the leaf litter, chemical composition of leaf litter and the nutrients released through leaf litter for recycling, in an eight year old rubber plantation of Vellanikkara Estate of Kerala Agricultural University have been attempted. During the year under study, wintering started by 14th December, 1991 and continued till 2nd March, 1992, the peak being the third week of January, 1992. During annual defoliation period total leaf litter production (dry weight) was estimated to be 4112 kg/ha, the contribution of which works out to annual addition of 63.3 kg N, 2.64 kg P, 44.0 kg K, 42.32 kg Ca and 8.93 kg Mg. During wintering, there is a gradual decline in the levels of nitrogen, phosphorus and potassium in leaves due to the shift of these nutrients to trunk. This shift was not abserved in the case of calcium and magnesium. Approximate leaf area index was also worked out and is found to be 4.26.