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