Effects of Astragalus Sinicus Combined with Rice Straw on Rice Production

In order to study the feasibility of replacing 20% conventional chemical fertilizer with Astragalus sinicus dressing or rice straw returning to field, by using the field experiment method, six different treatments were set up as follows: no fertilizer (CK), 100% chemical fertilizer, 20% reduction of chemical fertilizer, Astragalus sinicus dressing+100% chemical fertilizer, Astragalus sinicus dressing+20% reduction of chemical fertilizer, and Astragalus sinicus dressing+rice straw returning to field+20% reduction of chemical fertilizer. Then, the effects of Astragalus sinicus dressing or returning to the field combined with rice straw on the yield, economic benefit and soil properties of succeeding single cropping rice were studied. The results showed that compared with the treatment of 100% chemical fertilizer, the treatment of Astragalus sinicus dressing+rice straw returning to field+20% reduction of chemical fertilizer had the effective number of panicles at rice maturity increased by 14.8%, the yield of rice and straw respectively increased by 7.7% and 15.5%, and the economic benefit increased by 2013 yuan·hm^-2.Compared with the treatment of 100%chemical fertilizer,the treatment of Astragalus sinicus dressing+20% reduction of chemical fertilizer had the yield of rice and straw respectively increased by 1.4% and 3.1%. The soil fertility level could be improved by the treatment of Astragalus sinicus dressing+rice straw returning to field+20% reduction of chemical fertilizer, and the microbial biomass carbon, microbial biomass nitrogen, organic matter, total nitrogen and rapidly available potassium increased by 5.6%, 39.3%, 5.2%, 5.4% and 30.2%, respectively. In conclusion, under 20% reduction of chemical fertilizer, Astragalus sinicus dressing and rice straw returning to field could increase the rice yield and efficiency, and improve the soil fertility. Astragalus sinicus dressing+20% reduction of chemical fertilizer can maintain the stable yield of rice. Therefore, it was recommended to use 22 500 kg·hm^-2 Astragalus sinicus dressing and rice straw returning to field instead of 20% chemical fertilizer in the rice production.