Yield, quality and soil health under organic vs conventional farming in taro

Abstract

Growing concerns regarding food safety, environmental degradation and human health have generated interest in alternative agricultural systems like organic farming. This study aimed to compare growth, biomass, yield, proximate composition and mineral contents of tubers, physico-chemical properties and microbial population of soil under organic vs conventional farming in taro (Colocasia esculenta (L.) Schott.). Field experiments were conducted in split plot design over five seasons at ICAR-Central Tuber Crops Research Institute, India, with three varieties (Sree Kiran, Sree Rashmi and local) in main plots and three production systems in sub plots. Organic system (10.61tha−1) performed similar to that of conventional (11.12tha−1), with slight yield reduction (−5%). Both elite and local varieties responded equally well to organic management, which lowered the bulk density slightly and improved the water holding capacity (+19%) and porosity (+3%) of soil. Cormel quality was better under organic management, with higher dry matter, starch, sugars, P, K, Ca and Mg contents. Organic plots showed significantly higher pH (+1.2 unit) and available P and higher soil organic C (+39%), exchangeable Ca, Mg, Fe, Mn, Zn and Cu status. On-station developed technology involving farmyard manure, green manure, neem cake, biofertilizers and ash were on-farm validated at seven locations in southern India. The yield under organic management at farm level was higher by 29 per cent. Organic farming proved to be an eco-friendly alternative to conventional farming in taro for stable yield and quality cormels as well as for maintaining soil health.