为了探讨吉林省耕地表层氮素分布特征及影响因素,以吉林省703万公顷耕地为研究区域,根据2010年吉林省耕地地力评价数据(6169个耕地表层土壤采样点数据),辅以吉林省行政区划图、吉林省土壤图、土地利用现状图,利用ArcGIS技术以及分析软件...为了探讨吉林省耕地表层氮素分布特征及影响因素,以吉林省703万公顷耕地为研究区域,根据2010年吉林省耕地地力评价数据(6169个耕地表层土壤采样点数据),辅以吉林省行政区划图、吉林省土壤图、土地利用现状图,利用ArcGIS技术以及分析软件SPSS,计算了吉林省耕地表层土壤氮密度、储量,分析了其分布特征,并对影响吉林省耕地表层土壤氮密度的因素进行研究。吉林省耕地表层土壤氮密度平均值是0.473 kg m^(-2),氮储量为2902.13×103 kg。吉林省耕地表层土壤氮密度自东向西逐渐递减,东部、中部和西部平均值分别为0.611 kg m^(-2)、0.354 kg m^(-2)和0.307 kg m^(-2)。暗棕壤、黑钙土、草甸土、白浆土和黑土氮储量较高,占总储量的76.4%。土壤全氮含量和氮密度与海拔高度和年平均降雨量都呈极显著正相关,与年积温和pH都呈极显著负相关。展开更多
To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross ...To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross N mineralization rate （GNR） in mineral soils （0-10 cm） from six forest stands located in central Germany were determined and compared with two sampling times： April and November. Additionally, soil density fractionation was conducted for incubated soils （with addition of ^15NH4-N and glucose, 40 days） to observe the sink of added ^15N in different soil fractions. The study showed that Nmic and NNR in most stands differed significantly （P 〈 0.05） between the two sampling times, but not GNR, SAN and SON. In November, no close relationships were found between GNR and other N indices, or between Nrnic, SON, and SAN and forest type. However, in April, GNR was significantly correlated （P 〈 0.05） with Nmic, SAN, and NNR along with Nmlc under beech being significantly higher （P 〈 0.05） than under conifers. Furthermore, density fractionation revealed that the light fraction （LF, 0.063-2 mm, 〉 1.7 gcm^-3） was not correlated with the other N indices. In contrast, results from the incubation study proved that more 15N was incorporated into the heavy fraction （HF 〈 0.063 ram, 〉 1.7 g cm^-3） than into LF, indicaing that more labile N existed in HF than in LF. These findings suggested that attention should be paid to the differences existing in N status between agricultural and forest soils.展开更多
文摘为了探讨吉林省耕地表层氮素分布特征及影响因素,以吉林省703万公顷耕地为研究区域,根据2010年吉林省耕地地力评价数据(6169个耕地表层土壤采样点数据),辅以吉林省行政区划图、吉林省土壤图、土地利用现状图,利用ArcGIS技术以及分析软件SPSS,计算了吉林省耕地表层土壤氮密度、储量,分析了其分布特征,并对影响吉林省耕地表层土壤氮密度的因素进行研究。吉林省耕地表层土壤氮密度平均值是0.473 kg m^(-2),氮储量为2902.13×103 kg。吉林省耕地表层土壤氮密度自东向西逐渐递减,东部、中部和西部平均值分别为0.611 kg m^(-2)、0.354 kg m^(-2)和0.307 kg m^(-2)。暗棕壤、黑钙土、草甸土、白浆土和黑土氮储量较高,占总储量的76.4%。土壤全氮含量和氮密度与海拔高度和年平均降雨量都呈极显著正相关,与年积温和pH都呈极显著负相关。
基金Project supported by the German Research Council, Germany (No. DFG Graduiertenkolleg 339).
文摘To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross N mineralization rate （GNR） in mineral soils （0-10 cm） from six forest stands located in central Germany were determined and compared with two sampling times： April and November. Additionally, soil density fractionation was conducted for incubated soils （with addition of ^15NH4-N and glucose, 40 days） to observe the sink of added ^15N in different soil fractions. The study showed that Nmic and NNR in most stands differed significantly （P 〈 0.05） between the two sampling times, but not GNR, SAN and SON. In November, no close relationships were found between GNR and other N indices, or between Nrnic, SON, and SAN and forest type. However, in April, GNR was significantly correlated （P 〈 0.05） with Nmic, SAN, and NNR along with Nmlc under beech being significantly higher （P 〈 0.05） than under conifers. Furthermore, density fractionation revealed that the light fraction （LF, 0.063-2 mm, 〉 1.7 gcm^-3） was not correlated with the other N indices. In contrast, results from the incubation study proved that more 15N was incorporated into the heavy fraction （HF 〈 0.063 ram, 〉 1.7 g cm^-3） than into LF, indicaing that more labile N existed in HF than in LF. These findings suggested that attention should be paid to the differences existing in N status between agricultural and forest soils.
