Integrated nutrient management in tannia (Xanthosoma sagittifolium L. Schott): yield, plant nutrient concentration, plant uptake and soil chemical properties in an ultisol, Kerala

Abstract

Tannia (Xanthosoma sagittifolium L. Schott) is an important tropical tuber crop under aroids usually grownas an intercrop in plantations fetching good income. The leaves, corm and cormels are edible withgood nuetraceutical properties and high content of minerals especially K, Ca and Mg in leaves. AnIntegrated Nutrient Management (INM) package was evolved for this crop involving dolomite as soilamendment (@1 t ha-1) to correct sub soil acidity which usually hinders the growth and yield of thecrop along with FYM @ 25 t ha-1 as organic manure source and NPK @ 80:50:150 kg ha-1. By virtueof the organic nature of the crop, the N requirement was substituted with green manuring in situ withcowpea, neem cake and N efficient bio fertilizer to the extent of 75% and the remaining through urea.The INM strategy developed could rectify the nutrient disorder with increased corm and cormel yieldsto 12.821 and 12.863 t ha-1 over the existing adhoc recommendation of taro (FYM @ 12.5 t ha-1+NPK @80:50:100 kg ha-1) where the cormel and corm yields were 6.37 and 5.86 t ha-1 respectively.Though the plant dry weight percentages and plant nutrient contents were not affected, the leaf, cormand cormel dry matter production as well as total plant uptake of nutrients were affected either bylevels of dolomite, levels of K or their interaction effect. However, drastic variation was noticed in theplant nutrient contents and, in the corm, cormels and leaves, the N content was 1.446, 2.334, 2.40 %,P content was0.493, 0.333, 0.333 %, K content was 0.226, 0.419, 2.368 %, Ca content was 0.356,1.141, 1.029 %, Mg content was 0.079, 0.565, 2.492% and Mn content was 31.92, 40.83 and 147.5ppm respectively. Levels of dolomite significantly affected the post harvest soil pH, soil available Ca andMg and levels of K affected soil pH and K and the interaction effect was significant in the case of pHand K.Keywords: Tannia, Cormel, Corm, PoP, INM, Nutrients