水、肥添加对内蒙古典型草原土壤碳、氮、磷及pH的影响

Effects of water addition and fertilization on soil nutrient contents and pH value of typical grassland in Inner Mongolia

采用野外田间实验和室内分析相结合的方法,研究了水分、氮肥和磷肥添加对内蒙古典型草原土壤碳、氮、磷含量及pH的影响。结果表明:土壤有机碳和全氮含量对水、肥添加无显著响应;水分添加降低了土壤铵态氮(31.1%,P<0.01)和硝态氮(7.9%,P<0.001)含量,而添加氮肥显著增加了土壤铵态氮和硝态氮的含量(P<0.001);添加磷肥显著增加了土壤全磷和速效磷含量,分别为不施磷肥的1.7和5.9倍(P<0.001);水分添加提高了土壤pH值,氮、磷肥的添加均不同程度地降低了土壤pH值(P<0.001)。表明:水分以及氮肥、磷肥的添加对内蒙古典型草原土壤的性质具有明显的调节作用,这将为退化草地的管理提供科学参考。

With the combination of field experiment and laboratory analysis,this paper studied the effects of water addition and nitrogen（N） and phosphorus（P） fertilization on the soil properties of typical grassland in Inner Mongolia.Water addition and fertilization showed less effect on the soil organic C and total N contents.Water addition decreased the soil NH4＋-N and NO3--N contents by 31.1%（P 0.01） and 7.9%（P 0.001）,respectively,and N fertilization increased the soil NH4＋-N and NO3--N contents significantly（P0.001）.Under P fertilization,soil total P and available P contents were 1.7 and 5.9 times of the control,respectively（P 0.001）.Soil pH increased significantly with water addition（P0.001）,but decreased in different degree under N and P fertilization.All the results suggested the obvious effect of water addition and N and P fertilization in improving the soil properties in temperate grassland in Inner Mongolia,which would be of importance for the restoration and management of degraded grassland in North China.