桉-草经营模式的土壤物理性质及养分含量分析

Analysis on the Soil Physical Properties and Nutrient Content of Eucalypt-grass Management Model

对桉树人工林间种象草（Pennisetum americanum×P.purpureum）×（Pennisetum purpureum）复合经营模式的土壤物理性质及养分含量进行研究.结果表明：对比桉树纯林,桉-草经营模式的土壤容重降低了14.75％～22.12％,土壤总空隙度和毛管孔隙度分别提高了3.57％ ～ 16.51％和15.39％ ～ 18.67％,土壤饱和持水量和田间持水量分别提高了6.01％～34.14％和16.95％ ～43.99％,林地土壤物理性质得到改善.桉-草模式下林地土壤pH值降低了9.2％～10.5％,土壤有机质含量提高87.5％～24.2％;土壤全量N、P和速效N、P的含量提高7.06％ ～89.99％,提高幅度的大小排列顺序为速效N＞全量P＞全量N＞速效P,全量K和速效K含量减少,单位面积蓄积量提高14.14％.A层土壤理化性状改善幅度大于B层.桉树人工林间种象草复合经营模式,有助于改善林地土壤结构,提高林地养分含量,促进林木生长,是比较适宜推广发展的桉树复合经营模式.

The soil physical properties and nutrient content of Eucalypt-grass management model were studied. It showed that the soil bulk density of Eucalypt-grass management model reduced by 14.75% 22. 12% compared with the pure forest of Eucalypt. The soil total voidage and capillary porosity increased by 3.57% - 16. 51% and 15.39% - 18.67% respectively. The soil saturated capacity and the field ca- pacity increased by 6.01% -34. 14% and 16.95% -43.99% respectively. The soil physical properties were improved. The soil pH of Eucalypt-grass management model decreased by 9.2% - 10.5%. The soil organic matter content increased by 87.5% -24. 2%. The content of total N, P and the available N, P increased by 7. 06% - 89.99% with ordering by available N 〉 total P 〉 total N 〉 available P. The conient of total K and available K decreased. The per unit area of stock increased by 14. 14%. The soil physical properties of layer A was better than layer B. The Eucalypt-grass management model could im-prove the forest soil structure forest nutrient content, and growth of tree, which was very suitable for pro- moting.