摘要
以玉米N肥变量施肥为例,采用GIS技术对不同土壤肥力水平下的变量施肥尺度对施肥量、产量和肥料增产效率的影响进行模拟计算和可视化表达。首先用揟urning Band Method敺椒ㄋ婊煞现付ň怠⒎讲詈涂占浞植?半方差模型)的一组表示最小施肥单元的土壤养分数据,每组104个数据,对每组数据进行了100个等级尺度单元的相关效应计算和分析。模拟结果表明:(1)随着变量施肥单元面积减小,平均单位面积的施肥量增加或保持不变,产量一般增加,总的肥料增产效率也提高;(2)施肥临界养分过渡带的变量施肥合理性和产量受尺度影响较大,土壤肥力较高时,空间变异小,变量施肥尺度效应不明显。
In this study, the authors use GIS to simulate the influence of management zone size on variable-rate fertilization in soil with different soil nitrate levels. Field distribution dataset series of soil nitrate concentration in 500m?00m field were generated based on given mean, standard deviation and related distance. Each dataset is composed of nitrate concentration values at 104 cells, each being 5m?m in size. The amount of fertilizer used and yield of field unit from scale 100 to 1 were then calculated based on the generated soil nitrate distribution. The results show that when the size of a management zone decreases, precise fertilization will increase or maintain, instead of decreasing, the fertilization rate, and yield and nitrogen use efficiency will also increase. As the size of a management zone has much influence on reasonability for variant rate fertilization and yield in fertilization critical nutrient transitional areas, spatial variation becomes less and the scale effect on variable rate fertilization less significant when soil fertility is higher.
出处
《土壤》
CAS
CSCD
北大核心
2004年第6期615-620,共6页
Soils
基金
科技部国际合作重点项目2003DF020008和北京市优秀人才资金资助。
关键词
GIS
变量施肥
尺度效应
模拟
GIS, Variable-rate fertilization, Management zone, Influence
