节水灌溉下生物炭与有机肥添加对黑土区稻田净碳排放的影响

Effects of Biochar and Oganic Frtilizer Addition on Net Carbon Emission of Paddy Field in Black Soil Area under Water-saving Irrigation

摘要:

为探寻节水灌溉条件下施入生物炭与有机肥对黑土区稻田净碳排放的影响，于2023年开展田间试验。试验设置常规淹灌（F）和控制灌溉（C）两种灌溉模式，同时在每种灌溉模式下设置生物炭还田（B）和有机肥还田（O）2种物料还田形式，以及无物料还田（N）作为对照组，共计6个处理。分析了两种灌溉模式下施入生物炭与有机肥对稻田土壤CH4、CO2、N2O排放和水稻产量的影响，并结合土壤有机碳含量的变化，计算各处理的净温室气体排放量（NGHGE）。结果表明：在施入相同物料下，控制灌溉处理CH4排放总量较常规灌溉减少71.06%~85.39%；CO2、N2O排放总量较常规灌溉分别增加41.89%~47.97%、27.56%~38.26%。与对照处理相比，生物炭施入使稻田N2O、CH4排放总量分别降低14.31%~23.90%、15.10%~23.83%，CO2排放总量增加23.03%~26.63%；有机肥施入使稻田N2O、CH4、CO2排放总量分别增加8.22%~12.09%、18.36%~19.22%、51.48%~53.48%。生物炭与有机肥施入均能增加土壤有机碳储量与水稻产量，且控制灌溉下增幅效果更加明显。控制灌溉处理NGHGE均显著小于常规灌溉（P<0.05），且在控制灌溉下，与对照处理相比，施入生物炭与有机肥处理NGHGE分别减少44.01%、6.38%。综合来看，控制灌溉下施入生物炭提高了水稻产量，同时增加了土壤有机碳储量，并有效减少了黑土区稻田净碳排放。该研究结果可为东北黑土区稻田制定节水、增产、固碳减排的水碳管理策略提供科学依据，对保障东北地区可持续农业发展具有重要意义。

Abstract:

In order to explore the effects of biochar and organic fertilizer on net carbon emission from paddy fields in black soil area under water-saving irrigation, a field experiment was carried out in 2023. Two irrigation modes, conventional flooding irrigation (F) and controlled irrigation (C), were set up in the experiment. At the same time, biochar returning (B) and organic fertilizer returning (O) were set up in each irrigation mode, and no material returning (N) was used as the control group, a total of six treatments. The effects of biochar and organic fertilizer on CH4, CO2, N2O emissions and rice yield in paddy soil under two irrigation modes were analyzed. Combined with the change of soil organic carbon content, the net greenhouse gas emissions (NGHGE) of each treatment were calculated. The results showed that under the same material application, the cumulative CH4 emission of controlled irrigation treatment was 71.06%~85.39% lower than that of conventional irrigation. The cumulative emissions of CO2 and N2O were increased by 41.89%~47.97% and 27.56%~38.26%, respectively, compared with that of conventional irrigation. Compared with the control treatment, biochar application reduced the cumulative emissions of N2O and CH4 by 14.31%~23.90% and 15.10%~23.83%, respectively, and increased the cumulative emissions of CO2 by 23.03%~26.63%. The application of organic fertilizer increased the cumulative emissions of N2O, CH4, CO2 by 8.22%~12.09%, 18.36%~19.22%, 51.48%~53.48%, respectively. The application of biochar and organic fertilizer could increase soil organic carbon content and rice yield, and the increase effect was more obvious under controlled irrigation. The NGHGE of controlled irrigation treatment was significantly smaller than that of conventional irrigation (P<0.05), and under controlled irrigation, compared with the control treatment, the NGHGE of biochar and organic fertilizer treatment was decreased by 44.01% and 6.38%, respectively. In summary, the application of biochar under controlled irrigation increased rice yield, increased soil organic carbon storage, and effectively reduced net carbon emissions from paddy fields in black soil areas. The results can provide a scientific basis for the formulation of water and carbon management strategies for water saving, yield increase, carbon sequestration and emission reduction in paddy fields in the black soil region of Northeast China, and it was of great significance for ensuring sustainable agricultural development in Northeast China.