论文部分内容阅读
对耕地土壤有机质含量变化规律的研究是破解耕地土壤肥力变化规律及其效应的关键。本研究基于野外高密度土样采集,综合运用地统计学和GIS相结合的分析方法,从农户微观视角出发,研究了沈阳市典型区域30 a来在农户土地利用行为影响下土壤有机质含量时空变异特征。研究结果表明:研究区耕地土壤有机质含量受农户土地利用方式、程度和投入强度的变化影响较大。1980~2000年,由于受投资能力、技术水平和管理水平等的限制,加上对耕地的掠夺性经营,导致耕地土壤有机质含量整体呈现下降趋势,有机质含量平均值从30.88 g kg-1下降到22.63 g kg-1,下降了8.25%;随着城镇化进程的加快,在利益的驱使下,农户将劳动力逐渐转移到非农生产中,不愿意从事种植业,耕地培肥被忽视,管理投入大幅度减少,造成耕地土壤肥力供求失衡,地力下降,从2000~2010年整个研究区域土壤有机含量平均值从22.63 g kg-1下降到20.07 g kg-1。空间上,由于受区域社会经济及政策因素压力的影响,农户土地利用行为产生明显的分化,导致离市区越近,土壤有机质下降的幅度越大,离市区越远,下降的幅度越小,甚至远郊区部分区域出现上升趋势。
The study on the law of variation of soil organic matter content in cultivated land is the key to breaking the law and effect of soil fertility in cultivated land. Based on the field high-density soil sampling, comprehensively applying the combination of geostatistics and GIS, from the micro-perspective of farmers, the spatial and temporal variations of soil organic matter under the impact of land-use behavior of farmers in 30 typical years in Shenyang were studied. feature. The results showed that the organic matter content of cultivated land in the study area was greatly influenced by the change of land use pattern, degree and input intensity. From 1980 to 2000, due to the restriction of investment ability, technical level and management level, coupled with predatory management of cultivated land, the organic matter content of cultivated land decreased overall, and the average content of organic matter decreased from 30.88 g kg-1 to 22.63 g kg-1, a decrease of 8.25%. With the acceleration of urbanization, driven by the interests, farmers gradually shift labor force to non-agricultural production, unwilling to engage in planting industry, cultivated land fertilization was neglected, and management inputs The average soil organic content decreased from 22.63 g kg-1 to 20.07 g kg-1 in the entire study area from 2000 to 2010. Spatially, due to the pressure of social, economic and policy factors in the region, land-use behavior of farmers has been significantly differentiated, resulting in a closer drop from the urban area, the greater the extent of decline in soil organic matter, the farther away from urban areas, the smaller the extent of decline , Even some parts of the outer suburbs upward trend.