大寨海绵田土壤有机质、速效养分评价与空间分布

Evaluation of Soil Organic Matter and Available Nutrients and Spatial Distribution In Dazhai Mellow Soil

选取土壤有机质、速效磷、速效钾、水解氮4项指标,采用模糊隶属度函数(S型)计算隶属度值,用相关系数法确定各养分指标权重,确定养分评价综合指数值,进而对大寨典型海绵田土壤养分进行评价,并分析其空间分布特点。结果表明,研究区土壤水解氮含量较为贫乏,有机质含量总体上适量,速效磷和速效钾含量相对丰富。模糊综合评价结果表明,研究区土壤养分水平主要集中在Ⅱ、Ⅲ、Ⅳ级,大寨海绵田土壤养分处于适量状态。从空间分布来看,土壤养分模糊综合评价值由南北中部地区向东北、西南两侧递减,与有机质含量分布一致,速效磷和速效钾随地势增高呈递减趋势,水解氮则呈现出高低值交叉分布的复杂格局。

Integrated evaluation of Da-Zhai mellow soil nutrients were studied with four indexes of organic matter （OM）, available N（AN）,available P（AP） and available K（AK） with the method of correlation analysis. S-typed function were devel-oped according to their effect on plant, and the function values were also calculated. The weight value for the nutrient index was calculated respectively. The IFI （integrated fertility index） using the method was calculated. Finally, analyze the spatial distribution characteristics of Da-Zhai mellow soil nutrients. The results indicated that available P and K was relatively abun-dant, the content of available N was relatively low, and organic matter nutrient was in appropriate amount. Fuzzy synthetic e-valuation results showed soil nutrient status across the study area was classified mainly into rankⅡ, Ⅲ and Ⅳ. Soil nutrient status across the study area was actually in appropriate amount. From the spatial distribution, IFI values were descending from the central region to the northeast and southwest, consistent with the distribution of OM, AP and AK showed a decreas-ing trend with the increased terrain, nitrogen is showing complex pattern with low value cross-distribution.