Welcome to Journal of Agriculture,

Journal of Agriculture ›› 2023, Vol. 13 ›› Issue (8): 37-45.doi: 10.11923/j.issn.2095-4050.cjas2022-0113

Special Issue: 资源与环境 水稻 农业生态

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Effects of Continuous Straw Returning on Rice Yield and Nitrogen Utilization

MENG Ruoxi1(), WANG Xiaoli1(), DUAN Jianjun2, XU Bin1, YANG Hongwei1, MEI Tingting1   

  1. 1 College of Agriculture, Guizhou University, Guiyang 550025, Guizhou, China
    2 College of Tobacco, Guizhou University/ Key Laboratory of Tobacco Quality Research in Guizhou Province, Guiyang 550025, Guizhou, China
  • Received:2022-08-11 Revised:2022-11-07 Online:2023-08-20 Published:2023-08-16

Abstract:

To clarify the impact of straw returning ratio on rice yield and nitrogen utilization, a field plot positioning experiment was conducted in Tangtou Town, Sinan County of Guizhou Province during the rice growing season from 2019 to 2021. Six treatments were set up in the experiment: CK was no fertilizer, S0 was conventional fertilizer, S1 was conventional fertilizer + straw returning 5 t/hm2, S2 was conventional fertilizer + straw returning 10 t/hm2, S3 was conventional fertilizer + straw returning 15 t/hm2, and S4 was conventional fertilizer + straw returning 20 t/hm2. The results showed that from 2019 to 2021, the yield of S3 treatment was the highest, increased by 20.16%, 8.66% and 14.40% respectively compared with that of S0 treatment, and the yield increase in 2019 was the highest. The reason for the yield difference was that straw returning to field improved the number of effective panicles, the number of grains per panicle, 1000-grain weight and seed setting rate of rice, and then significantly increase the yield. The fitting analysis of straw returning and rice grain yield showed that the highest grain yield was achieved by straw returning amount of 15.43 t/hm2. Straw returning could improve the nitrogen partial factor productivity and nitrogen harvest index between years. In 2019, the nitrogen partial factor productivity of S3 treatment was the highest, while the nitrogen harvest index of S4 treatment was the highest, which were 42.81% and 24.30% higher than those of S0 respectively. In 2020, the nitrogen partial factor productivity and nitrogen harvest index of S3 treatment were the highest, with an increase of 55.98% and 22.61% over those of S0 treatment respectively; and in 2021, the nitrogen partial factor productivity and nitrogen harvest index of S3 treatment were also the highest, with an increase of 21.75% and 15.88% over those of S0 treatment, respectively. Straw returning increased the physiological utilization rate of nitrogen between years, and S3 treatment had the best effect, with an increase of 72.97%, 76.14% and 52.98% respectively compared with that of S0 treatment from 2019 to 2021. Moreover, year and straw returning treatment significantly improved the physiological utilization rate of nitrogen and agricultural efficiency of nitrogen. Therefore, considering rice yield, straw returning fitting results and nitrogen utilization rate, S3 treatment is more suitable for straw returning.

Key words: rice, straw returning, yield components, nitrogen utilization