自变量 系数 Independent variable Coefficients | 耕地地力等级Cultivated land fertility grade | |||
1 | 2 | 3 | 4 | |
表层土壤质地 Surface soil texture | 138.120 | 126.895 | 112.016 | 99.097 |
土壤剖面特征 Soil profile characteristics | 65.255 | 58.882 | 47.279 | 40.423 |
地表砾石度 Surface gravel degree | 53.563 | 56.784 | 55.777 | 38.759 |
土壤速效钾 Rapidlyavailable potassiumin soil | 226.449 | 211.825 | 194.910 | 177.568 |
土壤有效磷 Available phosphorousin soil | 259.720 | 232.774 | 211.605 | 191.291 |
有机质含量 Organic matter content | 341.849 | 313.147 | 286.183 | 267.767 |
灌溉保证率 Irrigation guarantee rate | 34.822 | 31.463 | 26.852 | 22.129 |
排涝能力 Drainage capacity | 160.030 | 155.024 | 145.853 | 131.919 |
地貌类型 Geomorphic types | 89.433 | 82.857 | 70.403 | 62.706 |
地面坡度 Ground slope | 138.956 | 134.640 | 128.033 | 105.360 |
常量 constant | −454.234 | −392.033 | −314.129 | −245.494 |