Soil Based Nutrient Management Plan for Tuber Crops in Pathanamthitta District of Kerala

Abstract

Soil fertility evaluation based on soil test is an inevitable pre-requisite for predicting fertilizer needs of crops. Fertilizer recommendation based on crop requirement and soil nutrient availability is one of the criteria to enhance nutrient use efficiency. In the present scenario of increasing fertilizer cost and over concern on human health, there is an urgent call from all corners for the rationalization of the existing package of practices (POP) recommendations for nutrient management based on innate soil fertility and crop requirement. In this regard, Kerala State Planning Board in collaboration with the Department of Agriculture, Government of Kerala, has initiated a project to develop soil based plant nutrient management plan for Kerala. The Central Tuber Crops Research Institute under Indian Council of Agricultural Research, one of the collaborators of this project, has evolved plant nutrient management plan for Pathanamthitta district based on chemical analysis of 10348 soil samples collected from various crops of the 51 panchayats of the district. As this district is one of the major tuber crops growing zones of Kerala, and 36% of the soil samples received from the district pertained to tuber crops  viz., cassava, elephant foot yam, yams, taro and tannia, an effort was made to prepare a nutrient management plan for these crops based on the soil test data generated. This paper deals with the innate fertility status (major, secondary and micronutrients) of the tuber crops growing soils as well as the nutrient management strategy developed for these crops based on soil test data. The soil test data indicated that the soils were strongly acidic with high organic C, available P, exchangeable K, Ca, Mg and S and sufficient in all micronutrients  viz., Fe, Cu, Mn, Zn and B. As the overall soil nutrient status of the district was found high, application of all the above nutrient containing fertilizers can be restricted to location and crop specific depending upon soil status and crop needs. As tuber crops form one of the major component crops of almost all predominant cropping systems of the district, the soil test data indicated the need for refinement of the existing package of practices of manures and fertilizers to maintain soil health and ensure higher income to farmers.