Objective To improve the fertilization efficiency of sweet potatoes, control soil acidification phenomenon, and explore the best fertilization management techniques.

Method On the basis of conducting a series of field experiments in the main sweet potato producing areas of Fujian province, the optimal ratio of organic fertilizer replacing chemical fertilizer and the optimal dosage of agricultural magnesium hydroxide or oyster shell conditioner were determined, explore the application effects of reducing fertilizer application to increase efficiency and improving acidity using these fertilization measures, finally summarize and propose the fertilization technology of organic-inorganic composite soil acidification conditioner

Result The experimental results of replacing chemical fertilizers with organic fertilizers showed that under the existing soil fertility conditions in Fujian province, replacing 25% of chemical fertilizers with organic fertilizers resulted in the highest sweet potato yield and a net increase of 13.5% compared to other substitution ratios. Further field experiments have shown that the application of organic fertilizer instead of 25% chemical fertilizer has a universal effect on increasing yield in different fertility levels of fields in the province. Sweet potatoes respectively increased their yields by 4.1%, 7.2%, and 18.5% in high, middle , and low yield fields .Compared with high-yield fields, the yield increase effect in middle yield fields and low yield fields is more significant, indicating that organic fertilizer can also improve soil fertility for middle yield fields and low yield fields, further enhancing the production potential of barren soils. The optimal dosage experiment of soil acidification conditioner showed that adding 300kg·hm⁻² of agricultural magnesium hydroxide or 1500 kg·hm⁻² of oyster shells on the basis of recommended fertilization had better effects on increasing yield and improving acidity. The field demonstration of fertilizer reduction and acidification treatment technology shows that the application of 300kg·hm⁻² agricultural magnesium hydroxide conditioner instead of 25% fertilizer with organic fertilizer significantly increases sweet potato yield by 4641.7kg·hm⁻² and soil pH by 0.49 pH units compared to conventional fertilization.

Conclusion On the basis of recommended fertilization, organic fertilizer replaces 25% of chemical fertilizers with applying 300kg·hm⁻² agricultural magnesium hydroxide conditioner or 1500kg·hm⁻² of oyster shells is the best fertilization technique for reducing fertilizer application to increase efficiency and soil acidification treatment.