【目的】研究长期施用不同量磷肥对农田土壤和作物碳(C)∶氮(N)∶磷(P)生态化学计量学、微生物活性及土壤碳库数量和稳定性的影响,为农田养分调控和生态系统稳定提供科学依据。【方法】以沈阳农业大学长期(28 a)地膜覆盖与施肥定位试验...【目的】研究长期施用不同量磷肥对农田土壤和作物碳(C)∶氮(N)∶磷(P)生态化学计量学、微生物活性及土壤碳库数量和稳定性的影响,为农田养分调控和生态系统稳定提供科学依据。【方法】以沈阳农业大学长期(28 a)地膜覆盖与施肥定位试验为平台,设置3个施磷处理:不施磷肥(P 0)、67.5 kg P_(2)O_(5)/(hm^(2)·a)(P_(1))、135 kg P_(2)O_(5)/(hm^(2)·a)(P_(2))。2015年秋季收获期采集0~20 cm土壤和玉米植株不同器官(根茬、茎秆、叶片、籽粒),测定土壤和作物C、N、P含量,土壤呼吸速率及土壤颗粒有机碳与矿质结合态有机碳含量。【结果】与不施磷肥相比,长期施用磷肥增加土壤全磷、速效磷、碱解氮含量及土壤pH,降低土壤C/P和N/P,对土壤有机碳、全氮含量及C/N无影响。施用磷肥增加了玉米器官磷含量,从而降低了N/P,但对玉米器官的C、N含量无影响。施用磷肥抑制了土壤呼吸速率(微生物活性),而对微生物量碳、可溶性有机碳、呼吸熵、微生物熵无显著影响。施用磷肥对土壤颗粒有机碳与矿质结合态有机碳的含量及其占总有机碳的比例无影响。【结论】长期施用磷肥因增加土壤和作物P含量而降低N/P和C/P,降低土壤微生物活性,但是对土壤有机碳库数量及稳定性无影响。展开更多
The microbial biomass C,N and P of soils all over China were determined in this study to study their affecting factors.The results,about 100-417 mg C kg^-1 soil,18-51 mg Nkg^-1 soil and 4.4-27.3mg P kg^-1 soil,showed ...The microbial biomass C,N and P of soils all over China were determined in this study to study their affecting factors.The results,about 100-417 mg C kg^-1 soil,18-51 mg Nkg^-1 soil and 4.4-27.3mg P kg^-1 soil,showed the biomass C,N and P in linear relationship with the soil total organic C,toal N and soil organic P.The ratios of C:Nand C:P,ranging from 5.6 to 9.6 and from 11.2 to 48.4 respectively,were affected by soil pH.texture,crop rotation,macroclimate etc.The ratio of C:N in soil biomass increases gradually from the north to the south in China.展开更多
文摘【目的】研究长期施用不同量磷肥对农田土壤和作物碳(C)∶氮(N)∶磷(P)生态化学计量学、微生物活性及土壤碳库数量和稳定性的影响,为农田养分调控和生态系统稳定提供科学依据。【方法】以沈阳农业大学长期(28 a)地膜覆盖与施肥定位试验为平台,设置3个施磷处理:不施磷肥(P 0)、67.5 kg P_(2)O_(5)/(hm^(2)·a)(P_(1))、135 kg P_(2)O_(5)/(hm^(2)·a)(P_(2))。2015年秋季收获期采集0~20 cm土壤和玉米植株不同器官(根茬、茎秆、叶片、籽粒),测定土壤和作物C、N、P含量,土壤呼吸速率及土壤颗粒有机碳与矿质结合态有机碳含量。【结果】与不施磷肥相比,长期施用磷肥增加土壤全磷、速效磷、碱解氮含量及土壤pH,降低土壤C/P和N/P,对土壤有机碳、全氮含量及C/N无影响。施用磷肥增加了玉米器官磷含量,从而降低了N/P,但对玉米器官的C、N含量无影响。施用磷肥抑制了土壤呼吸速率(微生物活性),而对微生物量碳、可溶性有机碳、呼吸熵、微生物熵无显著影响。施用磷肥对土壤颗粒有机碳与矿质结合态有机碳的含量及其占总有机碳的比例无影响。【结论】长期施用磷肥因增加土壤和作物P含量而降低N/P和C/P,降低土壤微生物活性,但是对土壤有机碳库数量及稳定性无影响。
文摘The microbial biomass C,N and P of soils all over China were determined in this study to study their affecting factors.The results,about 100-417 mg C kg^-1 soil,18-51 mg Nkg^-1 soil and 4.4-27.3mg P kg^-1 soil,showed the biomass C,N and P in linear relationship with the soil total organic C,toal N and soil organic P.The ratios of C:Nand C:P,ranging from 5.6 to 9.6 and from 11.2 to 48.4 respectively,were affected by soil pH.texture,crop rotation,macroclimate etc.The ratio of C:N in soil biomass increases gradually from the north to the south in China.