新疆耕地土壤养分时空变化

Spatial-temporal change of soil nutrients of cultivated land in Xinjiang

土壤养分状况是土壤肥力的重要标识,并决定着农作物产量高低,对其进行调查分析可以为今后土壤养分资源的综合评价和科学施肥管理提供基础资料。采用Meta-analysis方法,通过对1999-2005年期间有关新疆耕地土壤有机质、全氮、碱解氮、速效磷和速效钾的研究文献的收集分析,并与20世纪80年代全国第二次土壤普查数据对比分析,研究了近20多年来新疆耕地土壤养分的时空变化。结果表明耕地土壤有机质、速效磷和碱解氮总体呈现增加的趋势,土壤肥力在不断提高,全氮含量略有下降趋势,速效钾含量下降明显,但存在区域差异,准噶尔盆地北部区和伊犁地区具有较高的土壤肥力,塔里木盆地区域土壤肥力较低。分布于新疆的7种主要耕地土壤类型,其养分含量变化总体表现为与全疆耕地土壤养分相似的变化趋势。人类的施肥、耕作措施的改变及土地利用变化是引起土壤养分变化的主要原因。

Soil nutrient status is an important indicator of soil fertility to determine the crop yield. The investigation and analysis provides the basic information for future comprehensive evaluation of soil nutrients and fertilizer management resources. In this paper, a meta-analysis is used to analyze the data from 43 publications in the period from 1999 to 2005, to review the literatures for organic matter contents （OM）, total N （TN）, available N （AN）, available P （AP） and available K （AK）, to report the results of the spatial-temporal changes of soil fertility, and to explore the reasons for the changes. The results show that the soil OM is increasing, soil fertility is in continual enhancement, and the north area of the Junggar Basin has the highest content of soil OM （31.67 g/kg）, while the south area of Tarim Basin has the lowest one （9.15 g/kg）. AN is increasing, and Ili Prefecture ha~ the. highest content of AN （67.37 mg/kg）. AP is increasing rapidly, and Ili Prefecture has the highest content of AP, while the east area of Xinjiang has the lowest one （11.84 mg/kg）. TN shows a slight downward trend, and Ili Prefecture has the highest content of TN （ 1.63 g/kg）, while the south area of the Tarim Basin has the lowest one （0.47 g/kg）. AK decreases significantly, and Ui Prefecture has the highest content of AK （283.95 mg/kg）, while the east area of Xinjiang has the lowest one （104.37 mg/kg）. In short, there are regional differences in soil nutrients of Xinjiang; the cropland soil nutrients are high in Ili Prefecture and the north area of the Junggar Basin, and low in the Tarim basin. The seven major cropland soil types distributed in Xinjiang show similar trends. The improvement of soil fertility is mainly contributed to the more application of fertilizers, and the content of OM is affected by the changes of tillage and land use, which also altered the spatial distribution of soil nutrition to different degrees over the past 20 years.