固沙造林能使沙面稳定,沙土有机质及氮、磷含量增加。测试在我所固沙造林中间试验点王家进行。土壤、固沙造林前为流沙。林地土壤分为腐植质层(A_1)及淋溶层(A_2)取样测试分析。用未造林的流沙地做对照,比较有机质及氮、磷营养元素含量的变化。按照不同造林类型选6块标准地,调查林木的生长量及组成。见表1。固沙造林后(9—12年)林地枯枝落叶层厚度达0.7—1.5厘米,每0.1公顷的枯 Sand fixation can make the sand surface stable, sandy soil organic matter and nitrogen, phosphorus content increased. The test was carried out at Wang Jia, an intermediate test site where I was affirmative. Soil, sand fixation before the quicksand. The soil samples were divided into humus layer (A_1) and leaching layer (A_2) for sampling and analysis. Compared with the non-afforestation runoff sand, the changes of organic matter, nitrogen and phosphorus content were compared. According to the different types of afforestation 6 standard selected to investigate the growth of trees and composition. See Table 1. After afforestation (9-12 years), the litter layer thickness in forest land reaches 0.7-1.5 cm,