长顺冗雷河小流域草地治理模式下土壤肥力评价

采用野外调查和室内分析相结合的方法，对贵州省长顺县冗雷河小流域坡耕地、人工草地和天然草地3种地类的全氮和碱解氮，全磷和有效磷，全钾和有效钾，酸碱度，有机质进行了研究，以层次分析法进行肥力综合评价，揭示冗雷河小流域草地治理模式下对土壤肥力的影响。结果表明:坡耕地实施人工种草措施后，土壤全氮含量相对增加42.64%，碱解氮增加50.86%，中层和下层（20—30 cm）土壤碱解氮改善最为明显；土壤全磷含量相对增加45.24%，有效磷降低23.58%，坡耕地相比草地在全磷含量上相对较为匮乏，但用于作物吸收的有效磷素却高于人工草地；土壤全钾和有效钾含量降低，pH值无变化，其中全钾含量相对降低43.28%，有效钾降低37.32%；土壤有机质含量相对增加77.24%，其中表层（0—10 cm）、中层和下层土壤有机质含量分别提升48.06%，85.58%和107.78%，中层和下层土壤有机质含量改善幅度大。天然草地综合肥力指数最大，坡耕地最小，天然草地综合肥力指数是人工草地的1.09倍，是坡耕地的1.14倍，人工草地是坡耕地的1.05倍。土壤肥力整体水平上得到提升。

Soil Fertility Evaluation of the Small Ronglei River Watershed Under the Grassland Mode in Changshun County

By means of fields investigation and lab experiments, based on the planted grassland, the nature grassland and the slope farmland of the small Ronglei river watershed in Changshun, we have examined soil total nitrogen and alkaline hydrolysis nitrogen, total phosphorus and available phosphorus, total potassium, available potassium, pH and the organic matter, revealed the influence of the grassland mode on the soil fertility, and comprehensively evaluated the soil fertility by analytic hierarchy process (AHP) in the small Ronglei river watershed in Changshun. The result showed that: after the artificial grass measures had been carried out, soil’s total nitrogen content of farmland relatively increased by 42.64%, alkali solution nitrogen increased by 50.86%, the improvement of alkali-hydrolysable nitrogen in the subsoil layer (20—30 cm) was the most obvious. The content of soil total phosphorus relatively increased 45.24%, available phosphorus increased by 23.58%, the contents of total phosphorus in the farmlands are relatively deficient if compared to grassland, but the level of available P used by crops was higher than that of artificial grassland; soil total potassium and available potassium contents of farmland decreased, pH values presented no significant change; the content of total potassium relatively decreased by 43.28%, available potassium decreased by 37.32%; the content of soil organic matter relatively increased by 77.24%, the contents of soil organic matter in topsoil (0—10 cm), middle, and the deep layers increased by 48.06%, 85.58% and 107.78%, respectively, there was great improvement in the levels of soil organic matter in middle and deep layers. The Integrated fertility index of natural grassland is the maximum and the slope farmland is the minimum. Fertility index of natural grassland is 1.09 times of the artificial grassland, fertility index of natural grassland is 1.14 times of the farmland artificial grass. Fertility index of farmland artificial grass is 1.05 times of the slope farmland. The overall level of soil fertility was improved.