Nitrogen(N) losses in cropland resulting from the application of synthetic fertilizers decrease crop productivity and exacerbate environmental pollution.Mitigation measures, such as reduction in N fertilizer applicati...Nitrogen(N) losses in cropland resulting from the application of synthetic fertilizers decrease crop productivity and exacerbate environmental pollution.Mitigation measures, such as reduction in N fertilizer application rates, can have unintentional adverse effects on crop yield. We conducted a meta-analysis of soil N_(2)O emissions from agricultural fields across China under contrasting mitigation scenarios as a novel approach to identify the most effective strategy for the mitigation of emissions of N_(2)O derived from N fertilizer use in China. Current standard agricultural practice was used as a baseline scenario(BS), and 12 potential mitigation scenarios(S1–S12) were derived from the available literature and comprised single and combinations of management scenarios that accounted for crop yield. Mitigation scenarios S6(nitrification inhibitor 3,4-dimethylpyrazole phosphate) and S11(20% reduction in N application rate plus nitrification inhibitor dicyandiamide) in maize, rice, and wheat crops led to an average 56.0% reduction in N_(2)O emissions at the national level, whereas scenario S4(nitrification inhibitor dicyandiamide) led to yield optimization, with a 14.0% increase for maize and 8.0% increase for rice as compared to the BS. Implementation of these most effective mitigation scenarios(S4, S6, and S11) might help China, as a signatory to the 2015 United Nations Framework Convention on Climate Change(Paris Agreement), to achieve a 30% reduction in N_(2)O emissions by 2030.展开更多
●The Ascomycota played a major role in fungal necromass formation in soil.●Protists reduced fungal necromass while promoting bacterial ncromass accumulation.●Soil total nitrogen substantially decided the persistenc...●The Ascomycota played a major role in fungal necromass formation in soil.●Protists reduced fungal necromass while promoting bacterial ncromass accumulation.●Soil total nitrogen substantially decided the persistence of bacterial necromass in soil.Microbial necromass plays a crucial role in soil organic carbon(SOC)formation.However,underlying abiotic and biotic factors on necromass accumulation remain poorly understood.Here,based on a 27-year field fertilization experiment in upland Ultisols,we investigated how changes in fungal and bacterial necromass relate to the abundance,diversity,community structure,and trophic co-occurrence networks of microbial communities,including fungi,bacteria,and protists.Fungal necromass contributed an average of 32.4%to SOC,a greater contribution than the 14.6%from bacterial necromass,regardless of fertilization regimes.Modularity analysis of the protistan-fungal network indicated that Ascomycota fungi were the primary contributors to fungal necromass accumulation in arable soil.The protistan community structure had a significantly negative effect on fungal necromass by directly decomposing fungal residues,rather than altering the fungal community structure.In contrast,soil total nitrogen positively influenced the persistence of bacterial necromass.Bacterial abundance was positively correlated with bacterial necromass.Protists increased bacterial abundance,thereby increasing bacterial necromass in the soil.Overall,protists regulated microbial necromass storage in arable soils either by decomposing fungal necromass or by increasing bacterial abundance.展开更多
基金supported by the National Natural Science Foundation of China (No. 31561143011)the IAEA-Coordinated Research Projects (D1.5016, RAS5083)。
文摘Nitrogen(N) losses in cropland resulting from the application of synthetic fertilizers decrease crop productivity and exacerbate environmental pollution.Mitigation measures, such as reduction in N fertilizer application rates, can have unintentional adverse effects on crop yield. We conducted a meta-analysis of soil N_(2)O emissions from agricultural fields across China under contrasting mitigation scenarios as a novel approach to identify the most effective strategy for the mitigation of emissions of N_(2)O derived from N fertilizer use in China. Current standard agricultural practice was used as a baseline scenario(BS), and 12 potential mitigation scenarios(S1–S12) were derived from the available literature and comprised single and combinations of management scenarios that accounted for crop yield. Mitigation scenarios S6(nitrification inhibitor 3,4-dimethylpyrazole phosphate) and S11(20% reduction in N application rate plus nitrification inhibitor dicyandiamide) in maize, rice, and wheat crops led to an average 56.0% reduction in N_(2)O emissions at the national level, whereas scenario S4(nitrification inhibitor dicyandiamide) led to yield optimization, with a 14.0% increase for maize and 8.0% increase for rice as compared to the BS. Implementation of these most effective mitigation scenarios(S4, S6, and S11) might help China, as a signatory to the 2015 United Nations Framework Convention on Climate Change(Paris Agreement), to achieve a 30% reduction in N_(2)O emissions by 2030.
基金supported by grants from the National Natural Science Foundation of China(Grant No.42307400)Natural Science Foundation of Jiangsu Province(Grant No.BK20231097)+1 种基金the National Key Research and Development Program of China(Grant No.2023YFD1902705)China Postdoctoral Science Foundation(Grant No.2022M723239)。
文摘●The Ascomycota played a major role in fungal necromass formation in soil.●Protists reduced fungal necromass while promoting bacterial ncromass accumulation.●Soil total nitrogen substantially decided the persistence of bacterial necromass in soil.Microbial necromass plays a crucial role in soil organic carbon(SOC)formation.However,underlying abiotic and biotic factors on necromass accumulation remain poorly understood.Here,based on a 27-year field fertilization experiment in upland Ultisols,we investigated how changes in fungal and bacterial necromass relate to the abundance,diversity,community structure,and trophic co-occurrence networks of microbial communities,including fungi,bacteria,and protists.Fungal necromass contributed an average of 32.4%to SOC,a greater contribution than the 14.6%from bacterial necromass,regardless of fertilization regimes.Modularity analysis of the protistan-fungal network indicated that Ascomycota fungi were the primary contributors to fungal necromass accumulation in arable soil.The protistan community structure had a significantly negative effect on fungal necromass by directly decomposing fungal residues,rather than altering the fungal community structure.In contrast,soil total nitrogen positively influenced the persistence of bacterial necromass.Bacterial abundance was positively correlated with bacterial necromass.Protists increased bacterial abundance,thereby increasing bacterial necromass in the soil.Overall,protists regulated microbial necromass storage in arable soils either by decomposing fungal necromass or by increasing bacterial abundance.
