Scientific Reports (Sep 2022)

Effects of straw mulching combined with nitrogen application on soil organic matter content and atrazine digestion

  • Wan-feng Zhang,
  • Shu-qing Yang,
  • An Chang,
  • Li-ge Jia,
  • Ji-fang E

DOI
https://doi.org/10.1038/s41598-022-20097-8
Journal volume & issue
Vol. 12, no. 1
pp. 1 – 10

Abstract

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Abstract To explore the response of atrazine (AT) degradation rate, soil organic matter (SOM) distribution and the relationship between them to straw mulching and nitrogen application, field experiments were conducted to study the distribution of SOM content and AT degradation rate under different straw returning modes combined with nitrogen fertilization in 2 years in Hetao Irrigation District. No (N0), low (NL), medium (NM), and high (NH) levels of N fertilization were incorporated into the soil combined with the surface coverage straw (Treatment BN0, BNL, BNM, BNH, respectively) and the deeply buried straw (Treatment SN0, SNL, SNM, SNH, respectively). The traditional cultivation was used as a control treatment (Treatment CK). The results showed that SOM content of Treatment B was accumulated in 0~20 cm soil layer. The largest SOM content of Treatments B in 0~20 cm soil layer was found in BNH treatment, with an average increase of 14.2% and 24.1% significantly when compared with those in CK and SNH (P 0.05). Straw returning methods and nitrogen application level significantly affected AT digestion rate and digestion half-life, with significant differences among treatments (P < 0.05). It found that treatment SNM had the highest digestion rate and the shortest half-life of AT. Compared with Treatment CK, the digestion rate of Treatment SNM was increased by 5.3% on average, and the half-life was shortened by 3.9 days on average. Single regression and stepwise regression analysis of the half-life of AT degradation and SOM content in different soil layers (0~20 cm and 20~40 cm) showed that the degradation of AT was greatly affected by SOM content of 20~40 cm soil layer. Based on the comprehensive analysis, the effect of straw deep burial combined with medium nitrogen application rate (Treatment SNM) was best, which could achieve the goal of increasing SOM content and shortening the half-life of AT digestion. The research provided a technical support for straw resource utilization, alleviated AT pollution and improved farmland ecological environment in Hetao Irrigated District.