三峡库区不同植被恢复措施下土壤养分评价

通过对三峡库区不同恢复措施下土壤养分分析,研究了不同恢复措施对土壤pH、有机质、全量养分和速效养分的变化,并进一步对不同土壤养分进行了主成分分析.结果表明:研究区不同恢复措施下土壤均为酸性,表层土壤的pH值相对较低,且具有随土层深度的增加而增加的趋势;各恢复措施下均以0~20 cm土层中的有机质含量最高,与对照裸地相比,栾树+黄花槐、生物埂和封山育林措施土壤有机质明显提高;土壤全磷含量分布随土壤深度的增加波动较大;土壤碱解氮除传统农作和对照裸地外,其余各措施则表现出表聚现象,且从表层向下层呈递减趋势;除对照裸地外,有效磷含量随土壤深度的增加呈下降趋势,且以生物埂措施下土壤有效磷含量最高.各恢复措施下土壤养分的综合效应评价显示:栾树+黄花槐最大,为2.308;裸地最小,为-2.667.综合来看,随土层深度增加,土壤养分含量减少,适宜的恢复措施能够维持并提高土壤养分含量.

The Evaluation of Soil Nutrient on Different Restoration Measures in Three Gorges Reservoir Region

We measured soil nutrients in different restoration measures of in Three Gorges Reservoir Region. The effects of different restoration measures on soil pH, organic matter, nutrients and available nutrients were studied, and soil nutrients were analyzed by principal component analysis. The results showed that soil pH values were acidic in the study area, which was relatively low in the soil of profile surface, and it increase with the increasing of soil layer. The organic matter content of soil 0~20 cm under different restoration measures was the highest, and compared with the bare land, it increased significantly under Koelreuteria bipinnata+Cassia suffruticasa, biological border and closed forest measures. The distribution of total phosphorus content showed a great fluctuation with the increase of the soil depth. The available nitrogen declines from the surface soil to bottom soil, at the same time, it showed a surface gathering phenomenon under different restoration measures, except and traditional planting bare land control plot. In addition to the control of bare land, the available phosphorus content decline with the soil depth increased, and it was the highest under the biological border measures. Evaluation of soil nutrients in different restoration measures of comprehensive effect of K.bipinnata + C. suffruticasa measures was maximum (2.308). The bare land control plot was minimum (-2.667). In general, soil nutrient contents decrease with the increase of soil depth, and soil nutrient content can be improved through restoration measures.