Soil samples for conventional management (CM) and intensive management (IM) practices were taken over a year at 2-month intervals to determine the effect of management practices on soil organic carbon (SOC) and to qua...Soil samples for conventional management (CM) and intensive management (IM) practices were taken over a year at 2-month intervals to determine the effect of management practices on soil organic carbon (SOC) and to quantify seasonal dynamics in SOC for bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) stands. The results with IM compared to CM showed large decreases in total organic carbon (TOC), microbial biomass carbon (MBC), water-soluble organic carbon (WSOC), and the MBC/TOC ratio in the soils. With all IM plots in the 0-20 cm depth across sampling periods, average decreases compared with CM were: TOC, 12.1%; MBC, 26.1%; WSOC, 29.3%; the MBC/TOC ratio, 16.1%; and the WSOC/TOC ratio, 20.0%. Due to seasonal changes of climate, seasonal variations were observed in MBC and WSOC. Soil MBC in the 0-20 cm depth in September compared to May were 122.9% greater for CM and 57.6% greater for IM. However, due primarily to soil temperature, soil MBC was higher during the July to November period, whereas because of soil moisture, WSOC was lower in July and January. This study revealed that intensive management in bamboo plantations depleted the soil C pool; therefore, soil quality with IM should be improved through application of organic manures.展开更多
Fertilizer application efficiently increases crop yield, but may result in phosphorus(P) accumulation in soil, which increases the risk of aquatic eutrophication. Arbuscular mycorrhizal fungi(AMF) inoculation is a pot...Fertilizer application efficiently increases crop yield, but may result in phosphorus(P) accumulation in soil, which increases the risk of aquatic eutrophication. Arbuscular mycorrhizal fungi(AMF) inoculation is a potential method to enhance P uptake by plant and to reduce fertilizer input requirements. However, there has been limited research on how much P application could be reduced by AMF inoculation. In this study, a pot experiment growing asparagus(Asparagus officinalis L.) was designed to investigate the effects of AMF inoculation and six levels of soil Olsen-P(10.4, 17.1, 30.9, 40.0, 62.1, and 95.5 mg kg-1for P0, P1, P2, P3, P4 and P5treatments, respectively) on root colonization, soil spore density, and the growth and P uptake of asparagus. The highest root colonization and soil spore density were both obtained in the P1treatment(76% and 26.3 spores g-1soil, respectively). Mycorrhizal dependency significantly(P < 0.05) decreased with increasing soil Olsen-P. A significant correlation(P < 0.01) was observed between mycorrhizal P uptake and root colonization, indicating that AMF contributed to increased P uptake and subsequent plant growth.The quadratic equations of shoot dry weight and soil Olsen-P showed that AMF decreased the P concentration of soil required for maximum plant growth by 14.5% from 67.9 to 59.3 mg Olsen-P kg-1. Our results suggested that AMF improved P efficiency via increased P uptake and optimal growth by adding AMF to the suitable P fertilization.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 30271072) and the Zhejiang Provincial Natural Science Foundation of China (No. 301250).
文摘Soil samples for conventional management (CM) and intensive management (IM) practices were taken over a year at 2-month intervals to determine the effect of management practices on soil organic carbon (SOC) and to quantify seasonal dynamics in SOC for bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) stands. The results with IM compared to CM showed large decreases in total organic carbon (TOC), microbial biomass carbon (MBC), water-soluble organic carbon (WSOC), and the MBC/TOC ratio in the soils. With all IM plots in the 0-20 cm depth across sampling periods, average decreases compared with CM were: TOC, 12.1%; MBC, 26.1%; WSOC, 29.3%; the MBC/TOC ratio, 16.1%; and the WSOC/TOC ratio, 20.0%. Due to seasonal changes of climate, seasonal variations were observed in MBC and WSOC. Soil MBC in the 0-20 cm depth in September compared to May were 122.9% greater for CM and 57.6% greater for IM. However, due primarily to soil temperature, soil MBC was higher during the July to November period, whereas because of soil moisture, WSOC was lower in July and January. This study revealed that intensive management in bamboo plantations depleted the soil C pool; therefore, soil quality with IM should be improved through application of organic manures.
基金Supported by the National Key Basic Research Program(No.2013CB127401)the Strategic Priority Research Program of Chinese Academy of Science(No.XDB15030300)the National Natural Science Foundation of China(Nos.41001172 and 41371289)
文摘Fertilizer application efficiently increases crop yield, but may result in phosphorus(P) accumulation in soil, which increases the risk of aquatic eutrophication. Arbuscular mycorrhizal fungi(AMF) inoculation is a potential method to enhance P uptake by plant and to reduce fertilizer input requirements. However, there has been limited research on how much P application could be reduced by AMF inoculation. In this study, a pot experiment growing asparagus(Asparagus officinalis L.) was designed to investigate the effects of AMF inoculation and six levels of soil Olsen-P(10.4, 17.1, 30.9, 40.0, 62.1, and 95.5 mg kg-1for P0, P1, P2, P3, P4 and P5treatments, respectively) on root colonization, soil spore density, and the growth and P uptake of asparagus. The highest root colonization and soil spore density were both obtained in the P1treatment(76% and 26.3 spores g-1soil, respectively). Mycorrhizal dependency significantly(P < 0.05) decreased with increasing soil Olsen-P. A significant correlation(P < 0.01) was observed between mycorrhizal P uptake and root colonization, indicating that AMF contributed to increased P uptake and subsequent plant growth.The quadratic equations of shoot dry weight and soil Olsen-P showed that AMF decreased the P concentration of soil required for maximum plant growth by 14.5% from 67.9 to 59.3 mg Olsen-P kg-1. Our results suggested that AMF improved P efficiency via increased P uptake and optimal growth by adding AMF to the suitable P fertilization.
