Evaluation Of Soil Fertility In Farmland Tillage Of Winter Wheat And Summer Corn In Hebei Plain

Agriculture is a very important basic industry sector in China,and soil fertility evaluation is very important to agricultural production in China.There are many indexes related to farmland soil fertility,and the evaluation index system is greatly affected by the spatial position of cultivated land.Therefore,the construction of reasonable soil fertility index system is beneficial to farmers’ scientific management of agricultural production.In this paper,the physical and chemical characteristics of soil in cultivated land of wheat/corn rotation in low plain area of Hebei Province and Taihang Mountain Piedmont plain area,and the soil fertility evaluation system was established by principal component analysis method.The suitable range of fertility evaluation index under different yield levels is defined,and the fertility of Ningjin test site is determined by the method of principal component analysis The empirical study of the evaluation explored the effect of deep pine and organic fertilizer instead of compound fertilizer on soil fertility.The main findings are as follows:(1)The soil texture of farmland in low plain area is basically silty loam and sandy loam,Volume 1.39 g/cm3,Total porosity 47.70%,DR0.25 93.69%,Average weight diameter of aggregates(MWD)3.84mm,Average geometric diameter of aggregates(GMD)3.03mm,pH value 8.55,organic matter 14.66 g/kg,nitrate 10.05 mg/kg,available potassium 184.18 mg/kg,available phosphorus 18.12 mg/kg.The soil texture of farmland in the plain area of Taihang Mountain is sandy loam,Bulk density 1.31 g/cm3,total porosity 50.44%,DR0.2595.21%,MWD 3.46 mm,GMD 2.66 mm,pH value 8.06,organic matter 23.19 g/kg,nitrate 7.36 mg/kg,available potassium 189.26 mg/kg,available phosphorus 23.53 mg/kg.(2)Evaluation index system of soil fertility of wheat/maize farmland tillage layer in low plain area and Taihang mountain foothills plain area are bulk density,organic matter,GMD and available phosphorus;Weight of low plain area:bulk density 0.260,organic matter 0.244,GMD 0.263,available phosphorus 0.233,Weight of Taihang Mountain Piedmont plain area:bulk density 0.270,organic matter 0.248,GMD 0.252,available phosphorus 0.230.(3)The index range of high yield field between 18.00～20.00 t/hm2 in low plain area:bulk density 1.25～1.35 g/cm3,Organic matter 16.00～20.00 g/kg,GMD 3.10～3.50 mm,available phosphorus 19.00-22.00 mg/kg,The index range of high yield field between 18.00～20.00 t/hm2 in the plain area of Taihang Mountain:bulk density 1.25～1.38 g/cm3,Organic matter 22.00～24.00 g/kg,GMD 2.60～2.90 mm,available phosphorus 25.00～35.00 mg/kg.(4)The comprehensive index of soil fertility of farmland tillage layer combined with deep pine sowing and 20%organic fertilizer instead of compound fertilizer is 0.47,which belongs to the medium fertility level of 0.4～0.6,which is 0.12 higher than that of control field,6.82%～17.50%higher than that of single management measure.above all,there are some differences in the physical and chemical properties of winter wheat/summer corn rotation farmland tillage layer in low plain area and Taihang mountain foothills plain area.the evaluation index system of soil fertility in tillage layer is consistent,all of them are bulk density,organic matter,GMD and available phosphorus.increasing organic fertilizer and deep pine tillage can improve soil fertility.