武汉市汉南区土壤有机质和养分时空变异研究

Study on temporal and spatial variability of soil organic matter and nutrients in Hannan district of Wuhan

运用经典统计学及地统计学方法，研究汉南区土壤有机质和养分含量的空间变异特征。结果表明：碱解氮、有效磷、速效钾和有机质含量为中等水平，均服从正态分布；碱解氮和有机质符合球形模型，有效磷和速效钾符合指数模型。碱解氮和有机质的块金效应均在25%-75%之间，表明系统具有中等空间相关性。有效磷和速效钾块金效应均＆lt;25%，表明系统具有强烈空间相关性。在地理信息系统（ GIS）支持下，通过Kriging插值研究发现4种养分空间分布大体趋势是，东荆街办养分含量高，湘口街办和纱帽街办次之，邓南街办最低。从1980到2010年， pH值基本没有变化，有机质有降低的趋势，有效磷存在大幅提升，速效钾含量先大幅降低，后有所回升。培肥措施应为补施有机肥，稳施氮肥，优化磷、钾肥。

The spatial variability characteristics of soil organic matter （ OM ） , alkali hydrolysable nitrogen （ AN ） , available phosphorus （ AP） and available potassium （ AK） in the Hannan district of Wuhan city were studied through classic statistics and geostatistics. Results showed that content of OM and soil nutrients met normally distribution and were in middle level. The AN and OM content, which satisfied with the semi-variogram models, was best described by spherical model, AP and AK content was best described by exponential model. The nugget values of AN and OM accounting for 25% and 75%, and it indi-cated that the spatial variability were in moderate spatial correlation. The nugget values of AP and AK was low 25%, it indica-ted that the spatial variability were in strong spatial correlation. Based on spatial analysis of GIS, the results of Kriging showed that for the spatial distribution of soil nutrient contents, Dongjing street was the highest, Xiangkou street and Shamao street was second, and Dengnan street was the lowest. From 1980 to 2010 years, soil pH showed no change, OM content had a decrea-sing trend, AP content had been increased, AK content was decreased firstly and increased laterly. To improve soil fertility, organic manure application should be increased and NPK fertilizer should be optimized .