Objectives Quantitative classification methods of multi-point experimental data of fertilizer responses were studied to build fertilization categories of N, P and K fertilizers of early rice in county territory.
Methods Based on results of the 26 field experiments of " 3414”early rice response to N, P and K fertilization in Xianyou County, Fujian Province, China, applicability of different system clustering analysis methods and their significant differences were explored.
Results Based on the county experimental data of fertilizer response to production conditions and the little differences of production technology, and the best system clustering analysis method by Euclidean distance-Ward’s method for larger spatial extension between the categories, the 26 experimental datasets were clearly divided into three categories, which were corresponding to the high yield paddy, middle yield paddy and low yield paddy respectively in the county. There were significant differences between blank area yields and the yields of the balanced fertilization between two categories, and rice yields hardly overlapped among the three categories with the 95% confidence interval. Based on the three fertilization categories corresponding to the experimental data, class feature fertilization response function of quadratic polynomial was developed respectively, and then recommendation rates of fertilizers of the three fertilization categories were gained.
Conclusions System clustering analysis by Euclidean distance-Ward’s method is effective quantitative classification method for the county multi-point fertilization response data, and early rice can be divided into three fertilization categories of N, P and K fertilizers with statistically significant differences in Xianyou county.
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