Afforestation Technology in Rocky Mountain in Semi-arid Area in Jianping

The survival rate of forestation,the change of soil chemical properties with the planting years,and the influence of planting measures on soil chemical properties and the annual net growth of dbh and tree height have been studied for different plants in rocky mountain.The results show that the survival rates of different plants in rocky mountain are from 21% to 85%,and the survival rates of Ulmus pumila and Astragalus adsurgens are 81% and 85% seperaterly,and the survival rates of Populus simonii,Robinia pseudoacacia and Koelreuteria paniculata are about 70%.The vegetation can improve the content of organic matter,total nitrogen and P2O5,which the increasing degree is different with the different soil depth,nutrient varieties and planting years.In the same layer,bio-compound fertilizer,inocula and water retaining agent can increase the content of organic matter(p0.01) and decrease the content of P2O5(p0.01) obviously.Only water retaining agent can increase the content of total potassium obviously.The bio-compound fertilizer,inocula and water retaining agent can obviously increase the annual net growth of dbh and tree height of Populus simonii,Robinia pseudoacacia and Koelreuteria paniculata,which the water retaining agent has the highest improvement.