Wu Hongbao, Jin Yakang, Qi Yongjie, Huang Ruilin, Wang Fuwei
College of Resources and Environment, Anhui Science and Technology University, Chuzhou, China.
Front Plant Sci. 2025 May 21;16:1613163. doi: 10.3389/fpls.2025.1613163. eCollection 2025.
Fertilizer nitrogen (N) application has been shown to impact methane (CH) emissions, yield and quality from rice cropping systems, yet the responses of CH fluxes, yield and quality to N reduction and combined application of organic fertilizer in subtropical rice cropping systems are not well documented. Six experimental treatments were conducted: N90 kg N ha of urea (N1), organic fertilizer with equal N90 (O1) and 80% urea + 20% organic fertilizer (N1O1), farmer's common practice with N270 kg N ha of urea (N2), organic fertilizer with equal N270 (O2) and 80% urea + 20% organic fertilizer (N2O2) were conducted to simultaneously measure the CH flux, yield and quality from a subtropical rice cropping system in south China. Results showed that increased N fertilizer application significantly stimulated soil CH emission, increased rice yield and altered quality in paddy fields. CH emissions were quantified under different N fertilizer management practices in the peak rice growing season during the tillering and heading stages, respectively. Organic fertilizer alone increased CH emission by 442.1% in O1 and by 337.3% in O2 compared with urea. However, relative to organic fertilizer, organic fertilizer combined with urea significantly decreased CH emissions by 48.4% in O1 and by 39.2% in O2. Compared with N1 and N2 treatment, rice yield was significantly decreased by 34.4% and 39.5% under O1 and O2, while significantly enhanced by 49.8% and 22.3%, respectively, under N1O1 and N2O2 ( < 0.05). The protein content significantly increased under N1O1 by 18.8% and 41.5%, the amylose content by 30.3% and 14.8%, and the gel consistency by 32.7% and 15.5% in contrast to N1 and O1 ( < 0.05). Similarly, the protein content, amylose content and gel consistency under N2O2 were consistent with the rice quality under the N1O1 treatments above. In summary, optimizing organic fertilizer combined with urea practices was a win-win strategy to improve grain yield and quality while reducing CH emissions in the rice cropping system. This study provides new insights into the fertilizer types on CH4 emission and rice production of rice cropping systems.
氮肥施用已被证明会影响水稻种植系统中的甲烷（CH₄）排放、产量和品质，然而，在亚热带水稻种植系统中，CH₄通量、产量和品质对减氮和有机肥料配施的响应尚无充分记录。开展了6种试验处理：施90千克氮/公顷尿素（N1）、等量氮90的有机肥（O1）以及80%尿素+20%有机肥（N1O1），农民常规做法施270千克氮/公顷尿素（N2）、等量氮270的有机肥（O2）以及80%尿素+20%有机肥（N2O2），以同步测定中国南方亚热带水稻种植系统中的CH₄通量、产量和品质。结果表明，增加氮肥施用量显著刺激了稻田土壤CH₄排放，提高了水稻产量并改变了品质。分别在分蘖期和抽穗期的水稻生长旺季，对不同氮肥管理措施下的CH₄排放进行了量化。与尿素相比，单独施用有机肥使O1中的CH₄排放增加了442.1%，使O2中的CH₄排放增加了337.3%。然而，与有机肥相比，有机肥与尿素配施使O1中的CH₄排放显著降低了48.4%，使O2中的CH₄排放显著降低了39.2%。与N1和N2处理相比，O1和O2处理下的水稻产量分别显著降低了34.4%和39.5%，而在N1O1和N2O2处理下分别显著提高了49.8%和22.3%（P<0.05）。与N1和O1相比，N1O1处理下的蛋白质含量显著提高了18.8%和41.5%，直链淀粉含量提高了30.3%和14.8%，胶稠度提高了32.7%和15.5%（P<0.05）。同样，N2O2处理下的蛋白质含量、直链淀粉含量和胶稠度与上述N1O1处理下的稻米品质一致。总之，优化有机肥与尿素配施措施是提高水稻种植系统粮食产量和品质同时减少CH₄排放的双赢策略。本研究为肥料类型对水稻种植系统CH₄排放和水稻生产的影响提供了新的见解。
