| Sweet potato（Dioscorea esculenta（Lour.）Burkill）commonly known as Bai Shu,Hong Shu,Shan Yu,Di Gua,etc.,is a cultivated species of sweet potato（Ipomoea）in Convolvulaceae,belonging to annual or perennial herbs.However,with the development of the sweet potato industry law,farmers blindly increased chemical fertilizer in order to improve the yield and economic benefits of sweet potato.Due to unreasonable fertilization method and excessive application of nitrogen fertilizer.This has led to problems such as farmland soil hardening,microbial community disappearance,soil nutrient loss and low nutrient utilization rate,which has led to the decline of crop yield and quality year by year.In view of the problems of low soil fertility,weak soil environment,and decline of sweet potato yield and quality caused by excessive application of chemical fertilizers in the Three Gorges Reservoir Area,this paper compared the effects of adding Wanzhi Bioorganic Fertilizer（A1）and Bei Te Bioorganic Fertilizer（A2）on soil physical and chemical properties,soil microorganisms,yield and quality of sweet potato,and enzyme activity of sweet potato,using only compound fertilizer as control treatment（A3）.（1）Research on soil physical and chemical properties:through the study of soil PH value,soil bulk density,alkali-hydrolyzable nitrogen,available phosphorus,available potassium,organic matter and other relevant indicators.The results showed that the PH value decreased after adding bio-organic fertilizer.In terms of soil bulk density,increasing the application of A1 and A2 bio-organic fertilizers showed a downward trend,which could alleviate the soil consolidation;Adding bio-organic fertilizer can significantly increase soil organic matter and nitrogen,phosphorus and potassium content,among which adding A1 Wanzhi bio-organic fertilizer can significantly increase soil organic matter,which is 15.33%higher than A3.A2 Bei Te bio-organic fertilizer has the best effect in improving the content of nitrogen,phosphorus and potassium.Compared with the control,the content of nitrogen,phosphorus and potassium increased by 13.91%,12.64%and 34.44%respectively.（2）Research on soil microbial quantity:through the research on soil microbial quantity.The results showed that the amount of microorganism in soil could be significantly increased by adding two kinds of bio-organic fertilizers.Among them,after adding A1 Wanzhi bio-organic fertilizer,the number of microorganisms in the soil was the largest,which increased by46.98%compared with A3.（3）Study on sweet potato enzyme activity:Through the study on the activities of POD enzyme,CAT enzyme and MDA in sweet potato.The results showed that bio-organic fertilizer could effectively promote the growth and development of sweet potato,regulate enzyme activity,improve soil environment and reduce the impact of stress.（4）Research on yield and quality of sweet potato:through the research on the aboveground characters,underground yield,harvest index,soluble sugar content,reducing sugar content,crude protein content,carotene content and anthocyanin content of sweet potato.The results show that:;A1 Wanzhi bio-organic fertilizer has the best promotion effect on the aboveground part of sweet potato.As for the weight of potato per plant,the effect of A1 Wanzhi bio-organic fertilizer is better than that of A2Bei Te bio-organic fertilizer,and the weight of potato per plant is 30.73%higher than that of A3.In terms of plot yield,the effect of adding A1Wanzhi organic fertilizer was significantly higher than that of A3 control,and the yield increased by 17.29%.The effect of adding A2 Bei Te bio-organic fertilizer on commercial potato rate,commercial potato number and dry matter rate was the best,increased by 2.88%,6.05%and 7.49%respectively.Adding bio-organic fertilizer can significantly increase the soluble sugar,reducing sugar,crude protein,anthocyanin,carotene and other substances of sweet potato.Among them,A2Bei Te bio-organic fertilizer has the best effect on improving the content of soluble sugar,reducing sugar and carotene in sweet potato.Compared with A3,the soluble sugar content increased by 2.81%and the reducing sugar content increased by 10.56%.A1Wanzhi bio-organic fertilizer has the best effect on improving the content of anthocyanin and crude protein in sweet potato.Crude protein content increased by 9.30%compared with A3.Based on the above experimental studies,from the feasibility of planting operation,the soil physicochemical properties can be significantly improved under the treatment of a potassium sulfate type composite manure（50kg/667 m2）as the base fertilizer and an increase of500kg/667 m2 bioorganic fertilizer,which can effectively reduce the MDA content while it can have a favorable effect on the enzyme activity of sweet potato and ultimately improve the yield quality of sweet potato. |
