渭北台塬区耕地土壤速效养分时空变异特征  

SPATIAL-TEMPORAL VARIABILITY OF SOIL READILY AVAILABLE NUTRIENTS IN CULTIVATED LAND OF WEIBEI TABLELAND AREA

作　　者：于洋[1] 赵业婷[1] 常庆瑞[1] 

机构地区：[1]西北农林科技大学资源环境学院农业部西北植物营养与农业环境重点实验室,陕西杨凌712100

出　　处：《土壤学报》2015年第6期1251-1261,共11页Acta Pedologica Sinica

基　　金：国家高技术研究发展计划项目(863计划)(2013AA102401);高等学校博士学科点专项科研基金项目(20120204110013);陕西省耕地地力调查与质量评价项目共同资助

摘　　要：为充分了解渭北台塬区耕地土壤养分的时空变异特征,以渭北台塬典型农业县——蒲城县为例,基于该区1980年和2011年两个时期的实测样点速效养分数据,采用传统统计学、地统计学结合GIS技术,研究其耕地土壤碱解氮和有效磷的时空变异性、变化规律及其影响因素。结果表明,1980—2011年,该区土壤碱解氮、有效磷的块金系数增大,空间相关距缩短,标准化Z值降低,空间结构性特征减弱,随机因素作用增强。二者的平均含量分别提高84.32%、179.30%,呈现出原低值区增速快、高值区增速慢或略有降低的趋势;碱解氮/有效磷平均比值由7.22降至5.67,高、低值区发生逆转,氮磷失调问题得到改善,但仍高于农作物适宜水平。人为活动如施肥、灌溉等是土壤速效养分时空变化的重要影响因素。In order to fully understand the spatio-temporal variability of soil available nutrients in cultivated lands of Weibei Tableland, measured data of soil readily available nutrient contents in cultivated lands of Pucheng, a typical agricultural county of Weibei Tableland, in 1980 and 2011 were gathered and analyzed, using traditional statistics and geo-statistics in combination with GIS technology for spatio-temporal variation of alkalytic nitrogen （ AN ） , available phosphorus （ AP ） and its affecting factors. Significant differences were found between the two years in content of soil nutrients （p 〈 0.05 ） . In 2011, the average content of AN and AP was 75.11 mg kg-1 and 19.17 mg kg-1, respectively, or 84.32% and 179.30% higher than their respective one in 1980, but the mean AN/AP was 5.60 in 2011, 22.33% lower than that in 1980, which indicates that their variation coefficients （CV） of the two periods ranged between 35%- 77%, and ranked moderate in intensity. However, CVs of the two soil nutrients both increased, with CV of AP in particular, the CV of AN increased by 1.48% and of AP by15.21%. Obviously in the past 30 years the contents of soil AN and AP in the cultivated lands of Pucheng County increased significantly, with widened span between extremes and intensified variability. The semi-variance function and fractal dimension （ FD ） analyses of the data show that the contents of AN and AP were higher in 2011 than in 1980 in nugget/sill ratio and in fractal dimension, but narrower in spatial correlation distance. Meanwhile, the spatial autocorrelation analysis reveals that the normalized Z scores of Global Moran＇ s I of AN and AP were higher than 2.58, which indicates that the two were extremely significant in spatial autocorrelationship （p 〈 0.01 ） and in spatial clustering. Nevertheless, the Z scores of AN and AP in 2011 were lower than those in 1980. The results of the above-mentioned analyses are quite consistent, indicating that in the past 30 years, the spatial structure fe

关 键 词：土壤 碱解氮 有效磷 时空变异 

分 类 号：S153.6[农业科学—土壤学]