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Journal of Agriculture ›› 2024, Vol. 14 ›› Issue (12): 19-27.doi: 10.11923/j.issn.2095-4050.cjas2023-0253

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Effects of Biochar and Nitrogen Fertilizer on CO2 and N2O Emissions from Cotton Fields at Different Temperatures

WANG Jia1(), LIU Weiyang1(), HAO Xingming2, ZHANG Sheng2, HE Duo1, ZHANG Xiaogong1, ZHOU Limin1   

  1. 1 College of Agriculture, Tarim University, Alar 843300, Xinjiang, China
    2 Xinjiang Institute of Ecology and Geography, Urumqi 830000, Xinjiang, China
  • Received:2023-11-09 Revised:2024-03-26 Online:2024-12-20 Published:2024-12-20

Abstract:

The greenhouse gas emission rules under different farmland management methods were revealed, and the influencing factors and action mechanisms were expounded, so as to deal with greenhouse gas emissions from saline-alkali land in extremely vulnerable areas, mitigate climate change, and provided theoretical basis for greenhouse gas emission reduction in China. An extremely saline soil with electrical conductivity of 9.35 mS/cm and pH of 8.38 was used for indoor culture experiments. Three temperature gradients were set as 15, 25 and 35℃; three nitrogen application levels were set as 0, 120 and 240 kg N/hm2 and three biochar application levels were set as 0, 5 and 10 t/hm2. All treatments were carried out under 60% field water holding capacity and cultured for 45 days. The results showed that temperature and nitrogen application significantly increased CO2 and N2O emissions, and short-term application of biochar could reduce N2O emissions. (1) Under the same temperature and biochar conditions, the application of nitrogen fertilizer significantly increased greenhouse gas emissions. The cumulative emissions of CO2 and N2O at 120 kg N/hm2 were 2.02 times and 1.28 times of the control, respectively. The cumulative emissions of CO2 and N2O were the highest when nitrogen fertilizer rate was 240 kg N/hm2, which were 2.22 times and 1.64 times of the control, respectively. (2) Under the same temperature and nitrogen fertilizer conditions, the application of biochar significantly reduced the emission of N2O. Compared with the control, when the application rate of biochar was 5 t/hm2, the emission of N2O was reduced by 7%. The amount of biochar applied was 10 t/hm2, and the N2O emission was reduced by 13%. (3) Compared with 15℃, cumulative CO2 and N2O emissions at 25℃ increased by 11.34 g C/kg and 39.69 mg N/kg, respectively; the cumulative emissions of CO2 and N2O at 35℃ were the largest, increasing by 48.17 g C/kg and 69.69 mg N/kg, respectively. In summary, this study demonstrates that in the management of extreme saline-alkali soils in agricultural fields, reasonable control of temperature, nitrogen fertilization strategies, and the use of biochar are of significant importance for regulating greenhouse gas emissions.

Key words: dry land, temperature, fertilization, biochar, greenhouse gas emissions