Spatial-Temporal Variability Of Soil Available Nutrients In Citrus Orchard And Recommend Fertilization Based On GIS

Soil nutrients and crop yields have spatial within-field variability, changing with the time. In this study, the statistics, Geo-statistical methods, geographical information system technique and ASI were applied to understand spatial and temporal variability of soil nutrients and citrus yield in a citrus orchard with an area of 95.04hm~2 by grid sampling using global positioning systems in the Bapen village of Fusui Country, Guangxi Zhuang Autonomous Rigion. The maps of soil nutrients were drawn using GIS soft. Regionalized fertilization technology was studied based on the relationship between citrus yield and soil nutrients. Given level of significance, selection of the relative error of mean and identification the rational sampling number were discussed. The results were as follows:1. The results of statistics from the analytical results of soil character were shown as follows:(1) Soil available Ca and B had the greatest variation with coefficient of variation of 335.79% and 234.54%, respectively. The variability of pH, OM and soil available N, P, K, Mg, S, Cu, Zn, Fe, and Mn belonged to the mid-intensity variability, while pH had the lowest variation with a C.V.. of only 15.13%. The variability of pH and soil available K, Cu, Zn, Fe, Mn presented the trend of increasing with reducing altitude.(2) Examining normal distribution of the soil nutrient. Soil available S and Cu presented normal distribution, OM presented close normal distribution, soil available N, P, K, Ca, Mg, Zn, Fe and Mn presented logarithmic normal distribution, while pH was skewed distribution.(3) correlation coefficients of soil pH with the contents of available Mn were significant at...