The Influence Of Mountain Closing On The Properties Of Soil In The Limestone Forest

Closing hill is the most efficiency model to recovery the vegetation of eco-fragile area such as limestone. We studied the different year since mountain closed in Qiaomu village, Qingyang country, Anhui province to find out the influence of year since closing on the properties of soil in limestone and the relevance among nutrients. The mainly results as follows:Closing hill improved the soil bulk density, moisture content and pH. Closing hill reduced the bulk density, the trend is:0 year>5 years>10 years>30 years>20 years. There was significant difference of bulk density between 0 year and 5 years, but no significant difference among 5year,10 years,20 years and 30 years. The moisture content was increased after closing, the trend is:30 years>20 years>10 years>5 years>0 year. pH was reduced following the closing year prolong, presenting slightly acidic. The trend is:0 year> 5 years>20 years>10 years>30 years.Closing hill increased the soil organic matter, total nitrogen and available nutrients content. There was a slightly increasement of SOM with the closing year prolonged. The mountain which has closed for 20 years had the highest content of SOM, that is 57.72 g/kg. The content of total nitrogen was increased after closing and anived the peak at 30 years, that is 3.23 g/kg. Closing hill improve the content of available nutrients and the trend was 30 years>20 years> 10 years> 5 years> 0 year.Closing hill reduced the content of metal nutrients. The trend of total potassium and total magnesium was 0 years> 5 years>10 years> 20 years> 30 year. The trend of total phosphorus was 10 years> 0 years>5 years>20 year> 30 years. The content of total calcium was reduced as 0 year>5 years> 30 years> 10 years> 20 years.