草业科学Issue(10)：12-21,10.DOI:10.11686/cyxb2015154
青藏高原东部高寒草甸草地土壤物理性状对氮元素添加的响应
Effects of nitrogen addition on the physical properties of soil in an alpine meadow on the eastern Qinghai-Tibetan Plateau
摘要
Abstract
A 3-year study was conducted from 2012 to 2014 to determine the effects of nitrogen (N)addition on the physical properties of soil in an alpine meadow in Xiahe County on the eastern Qinghai-Tibetan Plateau.The four treatments were as follows:CK (control,no N addition),LN (low N,50 kg N/ha),MN (medium N,100 kg N/ha),and HN (high N,150 kg N/ha).Each N-addition treatment had three replicates of 54 m2 (6 m×9 m),with a 1.5 m isolation band between adjacent plots.Analyses of soil bulk density,soil porosity,soil compaction,and soil aggregates showed that MN and HN treatments reduced soil bulk density and soil compac-tion,increased soil porosity and non-capillary porosity,and maximized water-holding capacity in the 0-10 cm soil layer.In the 20-30 cm soil layer,compared with CK,all N-addition treatments showed higher soil bulk density and soil compaction,reduced soil porosity,and maximized water-holding capacity.In terms of the effect of N addition on the stability of soil aggregates in the 0-30 cm soil layer,the LN,MN,and HN treat-ments dramatically increased the macro-aggregate content (≥0.25 mm)and MWD (mean weight diameter), with the MN treatment having the strongest effect.Compared with CK,LN and MN dramatically improved the water-stable aggregate content.All of the N-addition treatments significantly promoted soil aggregation and in-creased the MWD of aggregates.The results indicated that N addition could effectively prevent soil erosion, and hence,control the loss of water and soil nutrients.The MN and HN treatments significantly increased the aboveground biomass in the grassland,while underground biomass was increased in the MN treatment and de-creased in the HN treatment.The results of this study showed that the MN treatment was the most beneficial treatment in terms of improving soil properties.This treatment increased soil bulk density,reduced soil porosi-ty,and increased soil compaction,increased the content of ≥0.25 mm soil aggregates and improved aggregate stability,and increased both the aboveground and underground biomass of plants in the grassland.关键词
高寒草甸/氮元素添加/土壤物理性状/土壤团聚体/土壤团聚体稳定性Key words
alpine meadow/nitrogen addition/soil physical properties/soil aggregates/soil aggregate stability引用本文复制引用
刘晓东,尹国丽,武均,陈建纲,马隆喜,师尚礼..青藏高原东部高寒草甸草地土壤物理性状对氮元素添加的响应[J].草业科学,2015,(10):12-21,10.基金项目
国家公益性行业（农业）科研专项《青藏高原社区畜牧业》课题201203010资助。 （）
