| In Ganzhou District, Zhangye City, Gansu Province, from 2018 to 2021, using field test methods, screening of multifunctional special fertilizer formulations was carried out by designing nine experimental treatments according to the orthogonal table L9 (35) with 5406 fungicide, multi compound fertilizer, water retention agent, polyvinyl alcohol and furfural residue as five factors and three levels for each factor; according to the screened formulations, the factors were mixed into multifunctional special fertilizers at the mass ratios of 0.059:0.881:0.013:0.040:0.007 mass ratios were mixed into a multifunctional special fertilizer, and the application rate of 0 t·hm-2 was used as the control (CK), and the following treatments were set up: 0.43 t·hm-2 (F1), 0.86 t·hm-2 (F2), 1.29 t·hm-2 (F3), 1.72 t·hm-2 (F4) and 2.15 t·hm-2 (F5) five fertilization gradients, to study the effects of different gradient application rates of multifunctional special fertilizer on soil properties, potato yield and economic benefits. The results showed that the formulation factors affecting the potato yield effect were as follows: multi compound fertilizer>water retention agent>polyvinyl alcohol>5406 fungicide>furfural residue; the optimal combination of multifunctional special fertilizer formulation factors was as follows: 5406 fungicide 101.25 kg·hm-2+multi compound fertilizer 1 500 kg·hm-2+water retention agent 22.50 kg·hm-2+polyvinyl alcohol 67.50 kg·hm-2+furfural residue 11.25 kg·hm-2.There was a significant positive correlation between the application rate of multifunctional fertilizer and soil porosity, aggregates, water storage capacity, available nitrogen, available phosphorus, available potassium, microbial population, botanical and economic traits of potato and yield, and a significant negative correlation with soil bulk density and pH. After regression statistical analysis, the fertilizer effect regression equation between the application amount of multifunctional special fertilizer and potato yield was y= 24.79 + 5.5687x - 0.4704x2, the best application amount for economic benefits was 1.72 t·hm-2, and the theoretical potato yield was 32.98 t·hm-2. In summary, it can be seen that the application of multifunctional fertilizer in Gansu potato dry cropping area effectively improved the soil physical and chemical properties and biological properties of the soil, and increased the yield and economic benefits of potato. |