| In recent years,with the constant adjustment of China’s agricultural structure in faciliti es,the vegetable planting area in facilities has been constantly expanded,which has fully promoted the rapid development of China’s vegetable production.Cucumber is the main cul tivated crop in the shed vegetable production in northern China,but the problem of contin uous cropping of cucumber and other main crops is increasingly serious due to the farmers’ planting habits and other problems in facility production.At the same time,due to the ma ximization of economic benefits and labor saving,a large number of pesticides and fertiliz ers are applied in the fields,which continuously deteriorate the soil environment and serio usly restrict the sustainable development of vegetable production in north China.As a tradi tional agricultural planting mode which can effectively prevent and reduce the occurrence o f continuous cropping obstacles and soil-borne diseases,crop rotation is conducive to the i mprovement of productivity of the facility ecosystem and the regulation of soil microbial e nvironment.Selecting suitable crops and rationally rotating them in a certain order is not o nly conducive to the growth and development of crops,but also can improve the physical and chemical properties of soil and the microecological environment.In this experiment,The seven different rotation cropping soils was taken as the resear ch object to explore the effect on the growth of cucumber seedlings and their soil environ ment,the aim is to find out the best rotation method which is beneficial to the growth of cucumber,it provides a theoretical basis for establishing a good vegetable cultivation syst em.The main results are as follows:1.The fresh and dry weights of cucumber seedlings in different rotation patterns were significantly higher than control.2.Tomato-celery-cucumber-cabbage,kidney bean-celery-cucumber-cabbage,cucumber-kidney bean-cucumber-cabbage,cucumber-tomato-cucumber-cabbage rotation patterns can significantly improve soil pH and significantly reduce soil EC value.The content of ammonia nitrogen,nitrate nitrogen and available potassium in different rot ation patterns soil was significantly lower than control,while the content of available phos phorus in soil was higher than control.3.The results of fluorescence quantification showed that the abundance of soil bacteri a in tomato-celery-cucumber-cabbage and cucumber-tomato-cucumber-Cabbage rotation was significantly higher than that in the control group.The soil fungal flora abunda nce of tomato-celery-cucumber-cabbage,string kidney bean-celery-cucumber-ca bbage,cucumber-string kidney bean-cucumber-cabbage and cucumber-tomato-cuc umber-cabbage were significantly lower than that of the control group.The abundance of pseudomonas was significantly higher in tomato-celery-cucumber-cabbage,string kidn ey bean-celery-cucumber-cabbage,cucumber-string kidney bean-cucumber-cabb age,cucumber-tomato-cucumber-cabbage.4.The results of correlation analysis showed that the abundance of soil bacteria in dif ferent rotation patterns was positively correlated with soil pH,available phosphorus,and negatively correlated with EC value,nitrate nitrogen,ammonia nitrogen and available pota ssium.The abundance of soil fungi in different rotation patterns was negatively correlated with soil pH value,and positively correlated with nitrate nitrogen and ammonia nitrogen.The abundance of pseudomonas was positively correlated with soil pH,available potassium,but negatively correlated with EC value,nitrate nitrogen,ammonia nitrogen and available potassium.5.Inoculation test results show that the tomato celery-cucumber,cabbage,cucumber,kidney bean-cucumber-cabbage,cucumber,tomatoes,cucumbers,cabbage rotation mod el of cucumber seedlings plants fresh and dry weight was significantly higher than other p rocessing,tomatoes,celery,cucumber,cabbage,kidney beans-celery,cucumber,cabbage,cucumber-kidney bean-cucumber-cabbage,cucumber,tomatoes,cucumbers,cabbage ro tation mode disease index was significantly lower than other processing.The results of corr elation analysis showed that the fresh weight and dry weight of the whole cucumber seedli ngs in different rotation patterns were positively correlated with the abundance of bacteria,pseudomonas and bacillus,and negatively correlated with the abundance of fungi.6.The results of plant-soil feedback experiment showed that the changes of soil micro organisms caused by different rotation patterns had positive feedback effect on the growth of cucumber seedlings.Overall,the rotation patterns of tomato-celery-cucumber-cabbage,cucumber-ki dney bean-cucumber-cabbage and cucumber-tomato-cucumber-cabbage increased t he biomass of cucumber seedlings and reduced the wilt index of cucumber seedlings by ch anging the soil chemical properties and microbial flora abundance. |
