Green Manuring Effect of Pure and Mixed Barley-Hairy Vetch on Rice Production

BACKGROUND: The mixtures of legumes and non legumes can be an efficient tool to combine the benefit of the single species in the cover crop practice. However, there is a lack of information on how the species proportion may affect N accumulation and how this can influence the nitrogen use of subsequent rice production. METHODS AND RESULTS: In this study barley and hairy vetch was selected as a green manure. The pure stands or mixtures with different seeding ratios was tested on green manure N accumulation and its following rice cultivation. Total aboveground biomass and N accumulation of mixture were higher compared to that of pure barley and hairy vetch. Among the mixtures, the highest aboveground biomass (8.07 Mg/ha) and N accumulation (131 kg/ha) was observed in B75H25 (barley 75% + hairy vetch 25%). The N accumulation of the mixture ranged from 99 kg/ha to 131 kg/ha which was much higher than amount of recommended (90 kg/ha) for rice. All mixture (barley 75%+hairy vetch 25%, barley 50%+hairy vetch 50%, barley 25%+hairy vetch 50%) produced 7-8% more rice yield than the conventional cultivation (NPK). The rice yield of in barley monocrop was 4% less than that of NPK. COLCLUSION(S): Adopting mixtures of barley and hairy vetch could be efficient strategy for rice production as an alternative of nitrogen fertilizer.