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研究了不同开垦年限对新疆绿洲农田土壤养分的变化规律,利用主成分得分的方法评价了开垦对新疆绿洲农田土壤质量的影响。结果表明:(1)开垦有利于新疆绿洲农田土壤有机碳组分和POC/MOC值,开垦初期(0~3a)增加迅速,9a后缓慢下降并趋于一个相对稳定的水平。(2)不同开垦年限土壤含水量、pH、电导率和全盐含量均显著高于未开垦土壤(p<0.05),土壤含水量和电导率在开垦初期(0~3a)急剧增加,在开垦6a前后达到最大值,此后的几年缓慢下降并趋于一个相对稳定的水平,土壤pH和全盐含量随开垦年限的增加而增加,开垦9a以后缓慢增加。(3)开垦9a以上土壤养分和有效养分含量均显著高于未开垦土壤(p<0.05),并且基本呈一致的变化趋势,即随着开垦年限的增加呈先增加后趋于平稳或者降低趋势。(4)相关性分析表明,不同开垦条件下土壤养分与有效养分均呈现出一定的相关性。(5)土壤质量的各项指标主成分分析结果表明,基本确定新疆绿洲农田开垦9a后土壤质量开始退化。综合上述结果可知:短期的开垦(开垦0~9a)则有利于提高新疆绿洲农田土壤肥力及土壤养分的有效性,而长期的开垦(开垦年限>13a)则造成土壤板结和盐渍化,降低了土壤养分及有效养分含量。
The changing rules of soil nutrients in oasis farmland in Xinjiang during different reclamation years were studied, and the influence of reclamation on soil quality in oasis farmland was evaluated by principal component score method. The results showed that: (1) Reclamation was beneficial to the soil organic carbon fraction and POC / MOC in farmlands of oasis in Xinjiang. During the early reclamation period (0-3 a), the soil organic carbon fraction and POC / MOC increased rapidly, and gradually decreased to a relatively stable level after 9 years. (2) Soil moisture content, pH, conductivity and total salt content in different years of cultivation were significantly higher than those in uncultivated soil (p <0.05), soil water content and conductivity increased sharply in the early stage of reclamation (0 ~ 3a) After 6 years, the soil pH and total salt content increased with the increase of reclamation years and slowly increased after reclamation for 9 years. (3) The contents of soil nutrients and available nutrients above reclamation 9a were significantly higher than that of uncultivated soil (p <0.05), and they were basically the same trend, that is, they increased first and then stabilized or decreased with the increase of reclamation years . (4) Correlation analysis showed that under different reclamation conditions soil nutrients and available nutrients showed a certain correlation. (5) According to the principal component analysis of each index of soil quality, the soil quality began to degenerate after basically confirming the reclamation of oasis farmland in Xinjiang for 9 years. According to the above results, short-term reclamation (reclamation from 0 to 9 years) is conducive to improving soil fertility and soil nutrient availability in oasis farmlands in Xinjiang, while long-term reclamation (reclamation period> 13a) causes soil compaction and salinization, Soil nutrients and effective nutrient content.