Zhao Chu, Sheng Mao-Yin, Bai Yi-Xin, Liu Shu-Xi
Institute of Karst Research, Guizhou Normal University, Guiyang 550001, China.
Guizhou Engineering Laboratory for Karst Rocky Desertification Control and Derivative Industry, Guiyang 550001, China.
Ying Yong Sheng Tai Xue Bao. 2021 Apr;32(4):1383-1392. doi: 10.13287/j.1001-9332.202104.018.
In this study, we collected soil samples from four different land use types (forest land, shrub land, grassland and abandoned land) in Huajiang valley of Guizhou Province, a typical karst rocky desertification area in Southwest China. Correlation analysis and redundancy analysis were used to examine the distribution of available nitrogen (N) and available phosphorus (P) in diffe-rent soil layers from 0 to 30 cm and the relationships between soil environmental factors (soil physical indexes, organic carbon components, electrochemical properties, metal oxides and enzyme activities) and the contents of available N and available P. The results showed that the concentrations of soil total N, total P, available N, available P decreased significantly with the increases of soil depth. The concentrations of soil available N and available P in forest land and shrub land were significantly higher than those in grassland and abandoned land, which were significantly positively correlated with soil organic carbon composition, enzyme activity, surface electrochemical properties and amorphous mental oxide while significantly negatively correlated with soil silt and free metal oxides. Results of the redundancy analysis showed that the environmental factors affecting soil availa-ble N and available P of the four land use types were basically the same, with soil particulate organic carbon, total organic carbon and soil specific surface area playing a key role in driving the variations of soil available N and available P. The efficient explanation of variation to soil available N and P contents by soil particulate organic carbon might be due to the reduction of soil nutrient loss by the storage of N and P in organic matter. Except for high enzyme activity and electrochemical properties of forest land and shrub land, the higher soil available N and available P concentrations compared with grassland and abandoned land might be resulted from the inhibition of free iron and aluminum oxides information by higher soil organic carbon content and the reduced adsorption and fixation of N and P by iron and aluminum oxides.
在本研究中，我们从中国西南典型喀斯特石漠化地区贵州省花江峡谷的四种不同土地利用类型（林地、灌木林地、草地和弃耕地）采集了土壤样本。采用相关性分析和冗余分析，研究了0至30厘米不同土层中有效氮（N）和有效磷（P）的分布情况，以及土壤环境因素（土壤物理指标、有机碳组分、电化学性质、金属氧化物和酶活性）与有效氮和有效磷含量之间的关系。结果表明，土壤全氮、全磷、有效氮、有效磷浓度随土壤深度增加而显著降低。林地和灌木林地土壤有效氮和有效磷浓度显著高于草地和弃耕地，与土壤有机碳组成、酶活性、表面电化学性质和无定形金属氧化物显著正相关，与土壤粉粒和游离金属氧化物显著负相关。冗余分析结果表明，影响四种土地利用类型土壤有效氮和有效磷的环境因素基本相同，土壤颗粒有机碳、总有机碳和土壤比表面积在驱动土壤有效氮和有效磷变化方面起关键作用。土壤颗粒有机碳对土壤有效氮和磷含量变化的有效解释可能是由于氮和磷在有机质中的储存减少了土壤养分流失。除林地和灌木林地具有较高的酶活性和电化学性质外，与草地和弃耕地相比，其较高的土壤有效氮和有效磷浓度可能是由于较高的土壤有机碳含量抑制了游离铁铝氧化物的形成，以及铁铝氧化物对氮和磷的吸附固定作用减弱所致。
