论文部分内容阅读
为了探讨护田林在于旱地区的效应,1980年4～9月,地、县林业部门在下马关公社刘家滩大队进行了“护田林效应观测”。测点设在北纬37°06′,东经106°32′,海拔1581米。观测地土壤为普通灰钙土,pH值8.7,含盐量0.02％,速效养分水解氮34.2ppm,磷14.0ppm,钾132.5ppm,有机质含量1％左右。林带宽10米,栽树5行,杨、柳、榆、沙枣、沙柳等单行混交,疏透
In order to discuss the effect of retaining Tianlin in the dry land areas, from April to September 1980, the prefectural and county forestry departments conducted the “observation of the effect of guarding the afforestation effect” at the Liujiatan Brigade of Xiamaguan Community. The measuring point is located at 37 ° 06 ’north latitude, 106 ° 32’ east longitude and 1581 meters above sea level. The soil in the observation area is ordinary ash soil with a pH of 8.7 and a salt content of 0.02%. The available nutrient hydrolyzed nitrogen is 34.2ppm, phosphorus is 14.0ppm, potassium is 132.5ppm and organic matter is about 1%. Forest bandwidth of 10 meters, planting trees 5 lines, Yang, Liu, Yu, dates, Salix and other single mixed, dredging