关键词: 农民工, 农民工, 留城意愿, 影响因素, 代际差异, Logistic模型

Abstract: In order to explore the effects of biochar and oil residue on soil nutrients and soil fertility and provide theoretical basis for soil fertility promotion in walnut garden in Wushi, Xinjiang, on the basis of conventional NPK fertilization, oil residue (27.3, 54.6 and 81.9 kg/plant) and biochar (168.2, 336.4 and 504.6 kg/plant) were added, the promotion effect was evaluated by soil fertility evaluation index (SFI) model of Wushi walnut garden. The results showed that soil organic matter, total and available nutrient were increased by adding oil residue and biochar, and the effect of oil residue was more significant. Oil residue increased the contents of Ca, Fe, Mn and Zn, but decreased the contents of Mg and Cu, biochar increased the contents of Ca and Mg, but decreased the contents of Mn and Cu. Compared with CK, the application of biochar and oil residue promoted soil fertility. In all the treatments of oil residue fertilizer, SFI reached the maximum when the application amount was 54.6 kg/plant, in all the treatments of biochar, SFI reached the maximum when the application amount was 168.2 kg/plant, and excessive application amounts of biochar and oil residue decreased soil fertility. Therefore, the optimum application amount was oil residue 54.6 kg/plant or biochar 168.2 kg/plant.