Utilization of composted bixa shell with different bioinoculants as soil amendment for ashwagandha and bixa growth.

Abstract

Efforts were made to test for efficient composting methods of bixa (Bixa orellanaL.) shell residues andassess their performance as soil amendment for valuable crop production. Five bioinoculants: earth-worms (T1),Trichoderma(T2),Trichoderma+Phanerochaete(T3), effective microorganisms (EM) (T4) andbiodynamic preparations (T5) were used in the study. The control consisted of composting withoutbioinoculants (T6). Bixa capsule shells were mixed with cow dung in 3:1 (w:w) proportion and the mix-ture was composted using the bioinoculants. The performance of the resulting composts was tested byusing them as soil amendment with NPK fertilizers and cattle manure as controls and growing two valu-able crops:Withania somnifera(ashwagandha) and bixa. The decomposition period was reduced by 85days when earthworms and EM were used as compared to uninoculated composting. Composting withbioinoculants resulted in an increase in total N (from 47.5% to 161%), available P (from 36% to 150%),exchangeable K (from 25% to 88%) and calcium (from 19.4% to 94.4%). T1,T3and T4recorded largernutrient content. Furthermore, these composts increased root yield (from 59% to 94%) and withanolidecontent (from 24% to 100%) in Ashwagandha and bixin content in bixa (22% and 28% over farmers practicein 3 and 4 year age plantations, respectively). The increased micro and macronutrient contents in thebioinoculated compost might be responsible for the higher yield and quality. Thus, earthworms, EM andTrichoderma+Phanerochaetewere effective bioinoculants for the preparation of nutrient rich compostfrom bixa capsule shells. Furthermore, on farm research revealed that vermicomposting is an efficient,easy and fast method of composting and that the final product is a potential plant nutrient source forsustainable crop production. The on farm research shows the practical value of composting recalcitrantbixa shells for satisfactory nutrient recycling and for the restoration of fragile agroecosystems.