Soil fertility and yield of tea under conventional and organic conversion system

Abstract

An experiment was laid out at the experimental tea garden of Tocklai under the CFC organic tea project, on mature tea converted to organic tea with an objective to evaluate the effect of organic conversion on soil fertility and yield of tea. The results indicated that the soil fertility level and nutrient content in shoot under organic tea plots could be maintained on a par with conventional systems by the addition of various organic inputs viz. vermicompost, cattle manure, decomposed neem cake, bio-fertilizers and foliar application of vermiwash. Soil organic carbon and microbiological properties, especially phosphate solubilising bacteria and microbial biomass C (Cmic), were considerably increased under organic tea plots, maintained by the application of vermicompost, either alone or in combination with farmyard manure (FYM) or mixed bio-fertilizer. Under all the organically managed plots, considerable built up of available P2O5 over initial was observed. However, available K2O decreased considerably. Soil potash status was depleting right from the first year of conversion, thus showing the requirement of potash supplementation permissible inputs. During organic conversion, crop loss occurred from the first year of conversion; conventional plot sustained significantly higher yield over all
the organically managed plots.