Organic Production of Greater Yam: Yield, Quality, Nutrient Uptake and Soil Fertility

Abstract

A field experiment was conducted at the Organic Farming Unit, Navsari Agricultural University, Navsari, during 2010-2011 and 2011-2012 to study the effect of different organic manures on yield, quality, nutrient uptake and soil fertility under organic farming in greater yam. Nine treatments were tested in this experiment. Among them, eight treatments were different combinations of organic manures. The control was the INM treatment (FYM @ 10 t ha-1 + NPK @ 80:60:80 kg ha-1) which was studied outside the organic farm. These treatments were tested in randomized block design with three replications. The results indicated that tuber and vine yield was higher under INM treatment, which was on par with organic treatments, T4 (biocompost @ 5.07 t ha-1 + neem cake @ 0.51 t ha-1) and T5 (vermicompost @ 4.72 t ha-1 + castor cake @ 1.35 t ha-1). Starch and carbohydrate contents of tuber were significantly enhanced under organic management. Total uptake of N, P and K were, however, significantly higher with INM treatment. Among the organic treatments, the treatment, T6 (vermicompost @ 7.08 t ha-1 + castor cake @ 0.68 t ha-1) resulted in higher total uptake of N, P and K over the other organic treatments during both the years. After harvest of the crop, higher organic C, macro and micro nutrients were observed in the organic treatments. The INM treatment generated higher net income of  ` 2,04,959 ha-1 and B: C ratio of 2.7 followed by the organic treatment, T6, (vermicompost @ 7.08 t ha-1 + castor cake @ 0.68 t ha-1) (net income of ` 1,88,643 ha-1; B: C ratio of 2.4).