流动沙漠腹地防护林土壤肥力质量垂直演化与评价

采用土壤肥力综合指数(IFI)评价法对塔里木沙漠公路防护林地土壤肥力质量垂直演化作了定量评价。结果表明:塔里木沙漠公路防护林建设后不同土层土壤的物理结构逐渐变好,透水、透气、持水能力有所增强;随防护林年限的增长,不同土层土壤生物活性提高,土壤微生物生物量碳、氮、磷的增加以及六种酶活性的增强促进了土壤养分的转化,多数养分因子在不同土层间差异明显;定植年限较长的防护林地土壤盐分含量增加,有表聚现象;同一林地不同土层之间土壤综合肥力指数差异很小,但与林木生长指标有较大相关性。在现有咸水滴灌条件下,塔里木沙漠公路防护林地土壤肥力质量良性发展。

Vertical variation and evaluation of soil fertility quality of windbreak forest soil in the hinterland of rolling desert

Quantitative evaluation of soil fertility quality of the soil under the windbreak forests alongside the Tarim Desert Highway was carried out with the IFI method (soil fertility integrated index). Results show that since the establishment of the windbreak forests, the physical structure, e.g. permeability, aeration property and water-holding capacity, of the soils thereunder has been improving in various soil layers, and so has the soil biological activity, which is manifested mainly in higher soil microbial biomass C, N and, P and enhanced activity of six enzymes, thus leading to stimulation of transformation of soil nutrients and hence differentiation of most nutrient elements between soil layers. Shelter forest soils, older in age, are higher in soil salt content, and display a phenomenon of salt accumulation in the surface soil. IFI values differ slightly between soil layers of the same soil profile, but is closely related to forest tree growth indices. In a word, the soil fertility quality of the shelter forests, drip-irrigated with salty water alongside the Tarim Desert Highway is on the way of continuous improvement.