内蒙古典型草原区土壤理化性质对不同利用方式的响应

Response of soil physical and chemical properties to different management modes in typical steppe of Inner Mongolia

草原土壤理化性质对草原生物多样性、畜牧业发展有重要影响。选取内蒙古锡林郭勒盟西乌珠穆沁旗天然牧场下不同利用方式的典型草原区为研究对象,运用土壤质量指数(SQI)对土壤理化性质与利用方式之间关系进行综合研究。结果表明:土壤有机质和速效氮含量随土层加深呈现先增加后减少的趋势,0~10 cm表层土壤含量显著高于其他土层,20~30 cm土层夏季草场有机质含量低于刈割草场(P<0.05),土壤速效磷,速效钾随土层呈现减少趋势且土层间差异显著(P<0.05),冬季草场0~5 cm速效磷显著高于其他利用方式(P<0.05),冬季草场速效钾含量高于低于其他利用方式(P<0.05),其余土层速效磷在利用方式间、冬季草场在土层间不显著;冬季草场土壤pH值显著高于其他利用方式(P<0.05),土层间pH值差异不显著,冬季草场表层土壤含水量极显著低于其他利用方式(P<0.01)。冬季草场SQI在0~5,10~20、20~30 cm三个土层上显著高于其他草场(P<0.01),5~10 cm刈割草场土壤质量指数最高(0.914),且显著高于其他利用方式(P<0.05),综合来看刈割草场和冬季草场土壤质量优于夏季草场,应当加强对夏季草场的合理利用,促进草地可持续发展。

The physical and chemical properties of grassland soil have an important impact on grassland biodiver⁃sity and animal husbandry development.Comprehensive analysis of soil quality index(SQI)was performed to investigate the relationship between soil physical and chemical properties and utilization patterns in typical grassland areas under natural pastures of Xiwuzhumuqin Banner in Xilin Gol League,Inner Mongolia.The results showed that the content of soil organic matter and available nitrogen increased first and then decreased with the soil layer,and that the content of 0~10 cm topsoil was significantly higher than that of other soil layers,the organic matter content of 20~30 cm soil layer in summer grassland was lower than that of mowed grassland(P<0.05).Besides,the content of soil available phosphorus and potassium showed a decreasing trend with the soil layer,and the differences between soil layers were significant(P<0.05).The available phosphorus content of 0~5 cm in winter pasture was significantly higher than that in other utilization modes(P<0.05),and the available K content in winter pasture was significantly higher than that in other utilization modes(P<0.05).The available P content in other soil layers was not significant among utilization modes or among soil layers in winter pasture.In winter,soil pH of grassland was significantly higher than that of other utilization methods(P<0.05),but there was no significant difference in pH between soil layers.In winter,surface soil water content of grassland was extremely significantly lower than that of other utilization methods(P<0.01).SQI of winter grassland in 0~5 cm,10~20 cm and 20~30 cm soil layers was significantly higher than that of other Grasslands(P<0.01).The soil quality index of 5~10 cm grassland was the highest(0.914),and significantly higher than that of other management methods(P<0.05).In conclusion,the soil quality of mowed grassland and winter grassland is better than that of summer grassland.We should strengthen the rational utilization of sum⁃mer grassland to promote the sustainable development of grassland.