海南岛土壤养分质量综合评价

Overall Assessment of Soil Nutrient Quality in Hainan Island

为了有效地调控和培肥土壤创造稳定高产的土壤条件,掌握土壤养分的演变规律提供科学依据,利用地统计学与GIS技术相结合的方法,综合评价了2个时期海南岛土壤养分质量状况。结果表明:海南岛土壤养分要素5项指标所占的权重分别是:pH19.58%、有机质18.45%、速效磷18.17%、碱解氮22.14%、速效钾21.67%;用同一综合指数标准将海南岛2个时期土壤养分质量等距划分为5个等级;1983年分布面积最广的是3级,为15169.9km2,占全岛总面积的44.68%;面积分布最小的等级是5级,仅占全岛总面积的1.24%,各等级分布面积大小顺序依次为3级>2级>4级>1级>5级。2007年集中分布在2级、3级和4级,1级和5级几乎没有分布,分布面积最大的3级,面积为21672.86km2,占据了海南岛土壤总面积的63.83%。从1983年到2007年,土壤养分质量各等级面积均发生了不同程度的变化,变化最大的是3级,最小的是5级,其余等级大小顺序依次为2级>4级>1级。

In order to effectively regulate and enrich the soil conditions for stable high-yield and a good understanding of changes of soil nutrients is necessitated. Geostatisties in combination of Geographical information system（GIS） was used for comprehensive evaluation of soil nutrient quality of Hainan Island in 1983 and 2007. The research result showed that the index weights of the soil nutrients in Hainan Island were 18.45% for organic matter, 18.17% for available P, 22.14% for alkali hydrolysable N, 21.67% for available K and 19.58% for pH. The soil nutrient quality was classified with equal distance into 5 grades in Hainan Island in 1983 and 2007. Most of the area fell within Grade 3 of the soil nutrient quality in 1983, covering 15 169.9 square kilometers, and the smallest area within Grade 5, only accounting for 1.24% of the total area. The area of various grades of the soil nutrient quality is in the order of Grade 3〉Grade 2〉Grade 4〉Grade l〉Grade 5. In 2007 the area mainly fell within Grades 2, 3 and 4, almost without Grades 1 and 5. The area at Grade 3 was the largest, covering 21 672.86 km^2 or about 63.83 % of the total soil area in Hainan Island. From 1983 to 2007, the area felling within different grades of the soil nutrient quality varied to some extent. The area under Grade 3 changed the most and the area under Grade 1 changed the least. The area under the other grades was in the order of Grade 2〉Grade 4〉Grade 1.