Production strategies of organic basmati rice in Tarai region of Uttarakhand, India

Abstract

Field experiments were conducted at G.B. Pant University of Agriculture and Technology, Pantnagar, India, during rainy season 2012 to 2014 to explore possible outcomes of sustainable production of organic basmati rice in terms of productivity, water use efficiency and methane emission reduction in North Western Himalayas of India. Six sets of nutrient management and production technology treatments were taken in randomized block design (RBD) with three replications. Traditional basmati rice variety type 3 popularly known as Dehraduni Basmati was taken for study. Dry matter production, crop growth rate and effective tillers were found higher in green manuring (GM) + vermicompost (VC) during all the 3 years. Overall highest grain yield of basmati rice (average over 3 years) was found in GM + VC with Sesbania aculeate (3209 kg ha−1) followed by System of Rice Intensification (SRI) (3174 kg ha−1), while lowest grain yield of basmati rice was recorded in organic control (2871 kg ha−1). However, only four treatments were considered to quantify methane (CH4) flux. Maximum CH4 flux was observed at panicle initiation stage (55 days after transplanting (DAT)). Across the crop growth period, GM + VC, farmyard manure (FYM) + VC, SRI and chemical control produced an average CH4 flux of 20.19, 13.00, 9.83 and 5.53 mg m−2 h−1, respectively. This shows that among the nutrient sources, CH4 emission was higher in organically fertilized plots as compared to chemically fertilized with urea at initial stages; however, at later stages, not much variation was observed in CH4 emission for different nutrient sources. Even with in organic system, less CH4 was emitted from SRI field where water was maintained through alternate wetting and drying system.