Studying On Agro-Forestry Models Of Young Taiwania Flousiana Plantation

To introduct and spread of Taiwania flousiana, provide some bases for utilizing forest resources effectively.Different model has been tested in Shankou Forest Farm of Nandan County, Guangxi Province, such as Taiwania flousiana with Oryza sativa(TH),Taiwania flousiana with Setaria italica var. germanica(TX), Taiwania flousiana with Oryza sativa(TY), pure forest of Taiwania flousiana(CK).We mainly research for these things, such like the growth situation of Taiwania flousiana, economic benefit, the soil changes in the experiment process, and the amount of the woodland Nutrient returning for finding out an optimal agro-forestry model.The results were indicated that:(1) Growth forms of Taiwania flousiana in planting system:the study showed that the survival rate for afforestation and to increase growth rate were better in agroforestry systems than in monotypic models,and the final best intercropping model could increased Taiwania flousiana plantations growth to a certain extent. While the impacts different intercropping model turned out to be small,the survival rate could reach more than95%and preserving rate reachesd above95%;The height,basal diameter growth and crown width were higher in agroforestry systems than in monotypic models, and the same time, the differences in growth increment enhanced with the increase of stand ages.Growth forms of Taiwania flousianain planting system, the agro-forestry models,to a certain extent, promoted the growth of the young Taiwania flousiana plantation, and the tree growth condition in order to:TY＞TH＞TX＞CK. (2) In economic matters, the short-term gain was achieved after Taiwania flousiana planting with different crops, and farmers income raised.The results also showed that continuous growth of crops for two years,with intercropping ages increased,the yield unit area could be reduced.The net income of crops varied from different intercropping patterns and the order was:TY (3925.8yuan/hm2)>TH (2972.7yuan/hm2)>TX (2881.8yuan/hm2).The order of amount of evaluation of forest properties in different intercropping patterns from high to low as:TH>TY>TX>CK.(3) The soil fertility status of soil all get a better improvement in the intercropping pattern of Taiwania flousianawith crop. Among them, in0～40cm soil layer, the water storage, ventilation and drainage effect of interplanting model was superior to than pure forest.Water holding capacity,ventilation function and drainage capacity was superior to the pure forest.The intercropping models mainly improved the soil oganic substance and the soil available nitrogen the soil urease, phosphatase, invertase in a certain extent, among those the nitrogen content of soil organic matter and alkali solution was significantly higher than that of Taiwania flousiana pure forest; On the comprehensive evaluation of soil fertility:TH>TX>TY>CK.(4) Crop residues was returned to the woodland, which was advantageous to the plantation soil fertility maintenance, and sustainable development.The order of amount of elements retaining in different intercropping patterns from high to low as:TX>TH>TY>CK.The accumulation of Nitrogen was the highest,while phosphorus was minimal.(5) TH model had some large gains in a relatively short time in the four models.The comprehensive effects in different models show the order:TH＞TY＞TX＞CK.