Comparison of kriging interpolation precision between grid sampling scheme and simple random sampling scheme for precision agriculture

Authors : Jiang HOULONG, Wang DAİBİN, Xu CHEN, Liu SHUDUAN, Wang HONGFENG, Yang CHAO, Li NAJİA, Chen YİYİN, Geng LİNA

Pages : 62-73

Doi:10.18393/ejss.2016.1.062-073

View : 61 | Download : 10

Publication Date : 2016-01-02

Article Type : Research Paper

Abstract :Sampling methods are important factors that can potentially limit the accuracy of predictions of spatial distribution patterns. A 10 ha tobacco-planted field was selected to compared the accuracy in predicting the spatial distribution of soil properties by using ordinary kriging and cross validation methods between grid sampling and simple random sampling scheme insert ignore into journalissuearticles values(SRS);. To achieve this objective, we collected soil samples from the topsoil insert ignore into journalissuearticles values(0-20 cm); in March 2012. Sample numbers of grid sampling and SRS were both 115 points each. Accuracies of spatial interpolation using the two sampling schemes were then evaluated based on validation samples insert ignore into journalissuearticles values(36 points); and deviations of the estimates. The results suggested that soil pH and nitrate-N insert ignore into journalissuearticles values(NO 3 -N); had low variation, whereas all other soil properties exhibited medium variation. Soil pH, organic matter insert ignore into journalissuearticles values(OM);, total nitrogen insert ignore into journalissuearticles values(TN);, cation exchange capacity insert ignore into journalissuearticles values(CEC);, total phosphorus insert ignore into journalissuearticles values(TP); and available phosphorus insert ignore into journalissuearticles values(AP); matched the spherical model, whereas the remaining variables fit an exponential model with both sampling methods. The interpolation error of soil pH, TP, and AP was the lowest in SRS. The errors of interpolation for OM, CEC, TN, available potassium insert ignore into journalissuearticles values(AK); and total potassium insert ignore into journalissuearticles values(TK); were the lowest for grid sampling. The interpolation precisions of the soil NO 3 -N showed no significant differences between the two sampling schemes. Considering our data on interpolation precision and the importance of minerals for cultivation of flue-cured tobacco, the grid-sampling scheme should be used in tobacco-planted fields to determine the spatial distribution of soil properties. The grid-sampling method can be applied in a practical and cost-effective manner to facilitate soil sampling in tobacco-planted field.
Keywords : Grid sampling scheme, Interpolation precision, simple random sampling scheme, precision agriculture

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