藏西沙化草地根系分布与土壤理化性质的关系

目的]调查和分析沙化过程中草地根系与土壤理化性质的关系,为藏西草地沙化的治理提供理论依据。方法]以西藏西部典型的沙化草地为研究对象,通过S采样法进行采样,对0-15 cm土层土壤理化性质进行研究。结果]随着沙化程度的加剧,土壤根系含量下降,pH值与速效钾含量先升高后降低,容重升高,含水量、有机质、全氮、碱解氮、速效磷降低。土壤根系含量与pH值和容重间存在极显著负相关关系(p<0.01),相关系数分别为-0.806和-0.735;与含水量、有机质、全氮、碱解氮和速效磷存在极显著正相关关系,相关系数分别为0.771,0.658,0.590,0.686,0.382。结论]草地沙化过程中植物根系含量与多个土壤理化性质指标存在相关关系,并受土壤理化性质的制约。

Relation Between Root Distribution Characteristics and Soil Physical and Chemical Properties in Desertification Grassland in Western Tibet

Objective] The relation between root system distribution and soil physical and chemical properties of grasslands was analyzed to provide a theoretical basis for the management of grassland desertification in Western Tibet.Methods] Grasslands with different degrees of desertification were taken as the research object. The sampling was undertaken according to the S-shaped method, and the physical and chemical properties of the 0-15 cm soil layer were analyzed.Results] The root content decreased with the aggravation of the desertification degree. As desertification progressed, both the pH value and available potassium first increased and then decreased, the volume weight showed an upward trend, and the soil water content, organic matter, total nitrogen, alkali-hydrolyzed nitrogen, and available phosphorus showed a downward trend. The root content of the grassland was significantly negatively correlated with pH value and volume weight (p<0.01), and the correlation coefficients were -0.806 and -0.735. The root content of the grassland was significantly positively correlated with soil water content, organic matter, total nitrogen, alkaline hydrolysis nitrogen, and available phosphorus. The correlation coefficients were 0.771, 0.658, 0.590, 0.686, and 0.382.Conclusion] Root distribution is correlated with many soil and chemical properties and restricted by soil physical-chemical proprieties.