【目的】研究生物质炭对连续两年稻田土壤性质、水稻产量和痕量温室气体排放的影响,为合理施用生物质炭而促进水稻生产可持续的低碳发展提供科学依据。【方法】选择成都平原稻田,2010年布设了施氮与否(0与240kgN·hm-2)下生物质炭土壤施用(0、20、40t·hm-2)试验,连续两年观测土壤性质、水稻产量、土壤CH4和N2O排放的变化。【结果】施氮肥条件下,生物质炭连续两年对主要土壤肥力性质表现出改善效应,提高了土壤有机碳、全氮含量和pH,同时降低土壤容重,但对水稻产量影响不显著。生物质炭对CH4排放的影响依氮肥施用而异。不施氮肥下,施用生物质炭提高当季土壤CH4排放(20t·hm-2用量时),但次年无影响。施用氮肥下,不同用量生物质炭对土壤CH4排放无显著影响,仅40t·hm-2用量时次年CH4排放有所增加;生物质炭对不施氮肥土壤当季N2O排放无显著影响,并降低次年的排放。然而,施氮肥下,生物质炭连续两年显著降低了土壤N20的排放,其降幅高达66%。施氮肥条件下,连续两年生物质炭处理降低稻田痕量温室气体的综合温室效应及其水稻生产的碳强度,特别是40t.hm-2的高用量下。【结论】在连续两年内,稻田采用生物质炭配施氮肥的管理措施对改善土壤性质和稳定水稻产量具有持续效应,高用量生物质炭(40t·hm-2)显著降低稻田CH。和N20痕量温室气体排放的综合温室效应和水稻生产的碳强度,且在连续两年内具有稳定的持续性。因此,在当前稻田管理措施下,生物质炭施用量为40t·hm-2可实现稻田稳产和固碳减排的目标。
[Objective] The effect ofbiochar on soil quality, rice yield and trace gas emissions in 2 consecutive rice growing cycles were investigated for providing a scientific basis for sustainable low carbon development office agriculture. [Method] A field experiment was initiated in a rice farm from Chengdu Plain with 0, 20 and 40 t.hm2of biochar soil amendment with (240 kg N.hm2) and without (0 kg N.hrn2) N fertilizer in 2010. Changes in soil fertility properties, rice yield and non-CO2 greenhouse gases emission in a whole rice growing cycle with biochar amendment were monitored throughout 2010-2011. [Result] Biochar amendments significantly increased soil organic carbon, total nitrogen, pH value and decreased bulk density of soil in both rice-growing cycles, when N fertilizer was applied, but it had no changes in rice yield. Biochar effect on CH4 emission varied with Nstatus. Increase of CH4 emission was observed only under low rate of 20 t.hm2 in the first cycle. However, no increase in CI4~ emission was found with N fertilization in the first cycle and even a decrease in the second cycle. With N fertilization, great decrease in N20 emission (by as high as 66% under 40 t.hm-2 of biochar amendment) was evidenced throughout the two cycles. Overall, biochar soil amendment tended to decrease the global warming potential and rice production carbon intensity from the two non-CO2 trace gases in the consecutive two rice cycles, under 40 t.hm-2 in particular. [Conclusion] Biochar soil amendment at 40 t.hm-2 could be a technical option to reach low carbon intensity and stable rice productivity in rice paddy agriculture.