Nitrous oxide （N 2 O） emissions from a maize field in the North China Plain （Wangdu County,Hebei Province,China） were investigated using static chambers during two consecutive maize growing seasons in the 2008 and...Nitrous oxide （N 2 O） emissions from a maize field in the North China Plain （Wangdu County,Hebei Province,China） were investigated using static chambers during two consecutive maize growing seasons in the 2008 and 2009.The N 2 O pulse emissions occurred with duration of about 10 days after basal and additional fertilizer applications in the both years.The average N 2 O fluxes from the CK （control plot,without crop,fertilization and irrigation）,NP （chemical N fertilizer）,SN （wheat straw returning plus chemical N fertilizer）,OM- 1/2N （chicken manure plus half chemical N fertilizer） and OMN （chicken manure plus chemical N fertilizer） plots in 2008 were 8.51,72.1,76.6,101,107 ng N/（m 2 ·sec）,respectively,and in 2009 were 33.7,30.0 and 35.0 ng N/（m 2 ·sec） from CK,NP and SN plots,respectively.The emission factors of the applied fertilizer as N 2 O-N （EFs） were 3.8% （2008） and 1.1% （2009） for the NP plot,3.2% （2008） and 1.2% （2009） for the SN plot,and 2.8% and 2.2% in 2008 for the OM-1/2N and OMN plots,respectively.Hydromorphic properties of the investigated soil （with gley） are in favor of denitrification.The large differences of the soil temperature and water-filled pore space （WFPS） between the two maize seasons were suspected to be responsible for the significant yearly variations.Compared with the treatments of NP and SN,chicken manure coupled with compound fertilizer application significantly reduced fertilizer loss rate as N 2 O-N.展开更多
The diversity and distribution patterns of soil nematode communities in phaeozem agroecosystems of Northeast China were assessed to evaluate nematode taxonomic diversity and functional diversity in relation to climati...The diversity and distribution patterns of soil nematode communities in phaeozem agroecosystems of Northeast China were assessed to evaluate nematode taxonomic diversity and functional diversity in relation to climatic condition and soil characteristics in human modified landscape. Along the latitudinal gradient, soil samples were collected from north （Hailun） to south （Gongzhuling） down to a depth of 100 cm with intervals of 030, 20-40, 40-60, 60-80, and 80-100 cm. The nematode abundance and taxonomic diversity （generic richness） were lower at Hailun than at other sites, and higher values of evenness were observed at Hailun and Harbin than at Dehui and Gongzhuling. Nematode faunal analysis revealed that soil food web at Hailun was sueeessionally more mature or structured, and the environment little disturbed, while at Harbin and Gongzhuling, the soil food web was degraded with stressed environment. The environmental variables relevant in explaining the patterns of nematode distribution and diversity in phaeozem agroecosystems, using canonical correspondence analysis （CCA）, were the mean annual temperature, total nitrogen, electrical conductivity, mean annual precipitation, and other soil properties. Among these variables, the mean annual temperature was a relatively important factor, which could explain 29.05% of the variations in nematode composition.展开更多
基金supported by the National Natural Science Foundation of China (No. 40830101,20977097, 41075094,21177140)the Special Fund for Environmental Research in the Public Interest (No. 201009001)+1 种基金the National Water Special Project (No. 2008ZX07421-001,2009ZX07210-009)the National Basic Research and the Development Program (973) of China (No. 2010CB732304)
文摘Nitrous oxide （N 2 O） emissions from a maize field in the North China Plain （Wangdu County,Hebei Province,China） were investigated using static chambers during two consecutive maize growing seasons in the 2008 and 2009.The N 2 O pulse emissions occurred with duration of about 10 days after basal and additional fertilizer applications in the both years.The average N 2 O fluxes from the CK （control plot,without crop,fertilization and irrigation）,NP （chemical N fertilizer）,SN （wheat straw returning plus chemical N fertilizer）,OM- 1/2N （chicken manure plus half chemical N fertilizer） and OMN （chicken manure plus chemical N fertilizer） plots in 2008 were 8.51,72.1,76.6,101,107 ng N/（m 2 ·sec）,respectively,and in 2009 were 33.7,30.0 and 35.0 ng N/（m 2 ·sec） from CK,NP and SN plots,respectively.The emission factors of the applied fertilizer as N 2 O-N （EFs） were 3.8% （2008） and 1.1% （2009） for the NP plot,3.2% （2008） and 1.2% （2009） for the SN plot,and 2.8% and 2.2% in 2008 for the OM-1/2N and OMN plots,respectively.Hydromorphic properties of the investigated soil （with gley） are in favor of denitrification.The large differences of the soil temperature and water-filled pore space （WFPS） between the two maize seasons were suspected to be responsible for the significant yearly variations.Compared with the treatments of NP and SN,chicken manure coupled with compound fertilizer application significantly reduced fertilizer loss rate as N 2 O-N.
基金supported by the National Key Basic Research Support Foundation of China (No.2005CB121105)the National Natural Science Foundation of China (No.30670379)
文摘The diversity and distribution patterns of soil nematode communities in phaeozem agroecosystems of Northeast China were assessed to evaluate nematode taxonomic diversity and functional diversity in relation to climatic condition and soil characteristics in human modified landscape. Along the latitudinal gradient, soil samples were collected from north （Hailun） to south （Gongzhuling） down to a depth of 100 cm with intervals of 030, 20-40, 40-60, 60-80, and 80-100 cm. The nematode abundance and taxonomic diversity （generic richness） were lower at Hailun than at other sites, and higher values of evenness were observed at Hailun and Harbin than at Dehui and Gongzhuling. Nematode faunal analysis revealed that soil food web at Hailun was sueeessionally more mature or structured, and the environment little disturbed, while at Harbin and Gongzhuling, the soil food web was degraded with stressed environment. The environmental variables relevant in explaining the patterns of nematode distribution and diversity in phaeozem agroecosystems, using canonical correspondence analysis （CCA）, were the mean annual temperature, total nitrogen, electrical conductivity, mean annual precipitation, and other soil properties. Among these variables, the mean annual temperature was a relatively important factor, which could explain 29.05% of the variations in nematode composition.
