新疆玛河流域绿洲农田开垦后土壤环境演变分析

Research on Successional Regulation of Soil Environment After Reclamation in the Manas River Valley

【目的】研究农田开垦后土壤退化特征及演变规律。【方法】以玛纳斯河流域绿洲为例,利用定位试验、空间替代法及主成分分析法,研究分析冲积扇下部绿洲农田开垦后土壤环境的变化过程。【结果】随开垦年限的增加,农田杂草群落由耐盐性多年生植被演替为1年生植被,演替序列主要集中在6～8年,而后进入平稳阶段。土壤耕层总盐变化呈现先降低后升高的趋势,而土壤养分表现为相反变化。主成分分析表明,农田开垦后土壤质量总体表现为良性发展而后开始退化,在开垦10年土壤整体质量状况趋向最大,而后综合评价值转为负值。【结论】可将10～15年作为反映该区域土壤质量总体退化的预警期。

[Objective and Method] This research taking the alluvial-fan oasis in Manas fiver as an example, through the fixed position experiments, the trend estimation model of principal component analysis and so on, the succession of plants and soil characteristics of field in the bottom of alluvial-fan oases were investigated and analyzed. [Result] With the increase of years of reclamation the salt-loving, perennial plants were substituted by annual plants and then entered a stable stage after 6-8 years. Total salt content decreased gradually and then increased, which reached the lowest after reclamation for 9.46 years. The soil nutrient showed the contrary to sail. The comprehensive quality of soil was a positive development in the first 10 years and then turned to degeneration. Through the trend estimation model of principal components analysis, farmland attains to the best performance in quality till 10 years. [Conclusion] Synthetically analysis the various index of the soil quantity, so 10-15 years could be used as early-warming time to reflect the change of soil quality.