砂姜黑土区花生田种植前后土壤肥力空间变异特征分析及评价

Spatial Variation Analysis and Comprehensive Evaluation of Soil Fertility for Peanut in Lime Concretion Black Soil Area

为明确砂姜黑土区花生种植前和成熟期土壤肥力状况及空间变异特征,本研究利用地理信息系统(GIS)和地统计学技术,运用模糊隶属度函数法,对河南省正阳县砂姜黑土土壤肥力状况及其空间变异特征进行分析。结果表明,与种植前相比,花生成熟期土壤有效硫含量明显下降,有机质、全氮、速效钾、有效铁和有效锌含量均有不同程度的提高,其中土壤全氮和有效磷含量增幅较大,分别增加10.17%和16.37%,但有机质和有效锌含量仍处于较低水平。花生种植前和成熟期土壤pH值变异系数分别为6.18%和6.36%,属弱变异,其余土壤养分指标变异系数介于12.58%~44.94%之间,属中等变异。不同土壤肥力指标对土壤肥力综合指标(IFI)的贡献存在差异,其中有机质含量对土壤肥力的贡献最大。半方差分析结果表明,花生种植前IFI的空间相关性较强,变异函数以球状模型拟合效果最好,空间分布特征主要受自然因素影响;花生成熟期IFI的空间相关性中等,变异函数以高斯模型拟合效果最好,空间分布特征受自然因素和人为活动共同影响。正阳县IFI多集中在0.58~0.72之间,表明土壤肥力整体处于中等偏上水平。另外,花生种植前IFI低于花生成熟期,且IFI空间分布呈南高北低的特征。综合分析,在正阳县砂姜黑土区花生生产上,应适当减少氮磷用量,增加有机肥和锌肥的施用,尤其是其南部地区。本研究结果可为砂姜黑土区花生优质高产的合理施肥和培肥地力提供科学指导。

To understand the status and spatial variation characteristics of soil fertility before planting peanut and at peanut maturity stage in the lime concretion black soil area of Henan province, the technology of GIS, geostatistics and fuzzy membership function method were used to analyze the status and spatial variability of soil nutrient in Zhengyang County, Henan Province. The results showed that, compared with pre-planting, the soil sulfur(S) content was decreased significantly, but organic matter(OM), total nitrogen(N), available phosphorus(P), available potassium(K), available iron(Fe) and available zinc(Zn) were increased at different degrees at peanut maturity stage, especially the content of soil total N and available P, which were increased by 10.17% and 16.37%, respectively. Soil organic matter and available Zn content were at a low level for pre-planting and maturity stage of peanut. The variation coefficients of soil pH at pre-planting and maturity stage of peanut were 6.18% and 6.36%, respectively, which belonged to weak variation. The variation coefficients of other nutrients ranged from 12.58% to 44.94%, which were at medium variation levels. The contributions of different soil fertility indicators to the soil fertility comprehensive index value(IFI) were different. The contribution of organic matter to soil fertility was the largest among all nutrients. The results of semi-variogram analysis showed that IFI had a strong spatial correlation before planting peanut, and its semi-variogram was best fitted by the spherical model, suggesting its spatial distribution characteristics were mainly affected by both natural factors;The IFI value at peanut maturity stage had a medium spatial correlation, and its semi-variogram was best fitted by Gaussian model, suggesting its spatial distribution characteristics were affected by natural factors and human activities. The IFI values in Zhengyang County were mainly distributed in 0.58~0.72, suggesting the soil fertility was generally above the medium levels, which were lower at pre-planting than that of peanut maturity stage, and its spatial distribution characteristics were higher in the south than in the north. Comprehensively, it should be recommended to reduce the usage of N and P fertilizers, and increase the application of organic and Zn fertilizer in the production of peanuts in the lime concretion black soil area of Zhengyang County, especially in the southern area.