生态果园建设对土壤物理特性的影响

Effect of ecological orchard construction on soil physical properties

四川省凉山州安宁河流域的半山坡地有5．3万hm^2，为了开发利用这些坡地，在西吕市西溪乡北河水库建设了以栽培批杷，石榴，李子和油橄榄，其下土壤套种绿肥植物紫云英，苜蓿，三叶草和黑麦草为主的生态果园作为示范．建设9年后，对生态果园内的土壤进行物理特性分析，与未建设果园的荒地作比较。结果表明，生态果园建设使土壤容重下降，除油橄榄和枇杷树下40～60cm土壤深度外，其余采样点的容重小于1．6g／cm^3，低于荒地容重。生态果园土壤的孔隙度比荒地土壤的孔隙度增加25．18％～31.70％，大于40％，平均44．41％。生态果园建设对土壤质地具有改良作用，土壤分散系数下降，结构系数升高。生态果园土壤水分含量高于荒地土壤60．0％以上，最高达144．2％，果园建设对土壤保水保肥有益。建议在安宁河流域种植根系发达，雨季需水量大，干季耐旱的果树品种。

For exploiting and utilizing the slope land soil of 53 000 hm^2 located in Anning river region of Liangshan, Sichuan province, an ecological orchard was constructed as example in Balhe reservoir of Xixi town, Xichang city,in which the fruit trees including loquat, pomegranate, plum and olive were cultivated with interplanting Chinese milk vetch,lucerne, trphyllous grass and black wheat. After 9 years of construction, the soils were sampled and analyzed for the physical properties compared with those of wasteland soil, The results showed unit weight in orchard soil decreased, Except for soil samples from under olive tree and 40 -60 cm depth under loquat tree,the unit weight of soil samples were all less than 1.6 g/cm^3 ,which was lower than wasteland soil. The porosity of orchard soil was higher than 60 % and average was 44. 41% ,which was 25.18 % -31.70 % more than that of wasteland soil. The ecological orchard construction improved soil texture with dispersion coefficient＇ s declining and structure coefficient＇ s rising. The water content of orchard soil was 60.0 % higher than that of wasteland soil ,even maximum 144.2 % higher. Orchard construction was beneficial for water and fertilizer conservation, Cultivating the fruit tree cultivats with root system development, drought resistance in arid season and waterlogging resistance in rainy season was put forward.