人为干扰活动对玛纳斯河流域棉田土壤容重的影响

Effect of Human Disturbance on Soil Bulk Density of Cotton Field in Manas River Basin

本文将玛纳斯河流域划分为山前绿洲、人工平原绿洲和绿洲与荒漠过渡带三个研究区,于2019年5、8和10月对绿洲区膜下滴灌棉田土壤容重进行采样,基于地统计学方法和ArcGis技术对棉田土壤容重进行空间异质性分析。结果表明:1) 玛纳斯河流域棉田土壤容重的季节变化规律为5月(出苗期) 】10月(吐絮期) 】8月(花铃期),其棉田土壤容重各季节变异程度均属于中等;在水平方向上,各季节的0~60 cm的土壤平均容重均呈现出人工平原绿洲 】绿洲与荒漠过渡带 】山前绿洲土壤的分布格局;在垂直剖面上,5月和八月土壤容重表现出由浅层至深层增加的趋势,但10月土壤容重表现出由浅层至深层下降的趋势;2) 经地统计学分析表明,人工绿洲土壤容重存在强空间自相关性,受结构因素影响大,山前绿洲和绿洲与荒漠过渡带土壤容重空间自相关性较弱,受随机因素影响大。研究表明土壤质地和有机质含量的空间分布差异是造成玛河流域棉田土壤容重呈现条带状和斑块状分布格局的主要因素,人为耕种制度和棉花生长导致土壤容重呈现季节变化。

In this paper, the Manas River basin was divided into three study areas: Piedmont oasis, artificial plain oasis and oasis-desert transition zone. Soil bulk density of cotton field under drip irrigation under plastic film was sampled in May, August and October 2019, and the spatial heterogeneity of soil bulk density of cotton field was analyzed based on geostatistics and Arcgis technology. The results showed that: 1) the seasonal variation of soil bulk density of cotton field in Manas River basin was May (seedling stage) >October (boll opening stage) >August (flower and boll stage), and the seasonal variation of soil bulk density of cotton field was moderate. In the horizontal direction, the average soil bulk density of 0~60 cm in each season showed the distribution pattern of artificial plain oasis >oasis and desert transition zone >Piedmont oasis soil distribution pattern. In the vertical profile, the soil bulk density increased from shallow layer to deep layer in May and August, but decreased from shallow layer to deep layer in October;2) Geostatistical analysis shows that there is a strong spatial autocorrelation of soil bulk density in artificial oasis, which is greatly affected by structural factors, while the spatial autocorrelation of soil bulk density in Piedmont oasis and oasis-desert transition zone is weak and greatly affected by random factors. The results showed that the spatial distribution differences of soil texture and organic matter content were the main factors leading to the banded and patchy distribution pattern of soil bulk density in cotton fields in Mahe River basin, and the soil bulk density changed seasonally due to artificial farming system and cotton growth.