Analysis on Continuous Cropping Obstacles of Dicyophora indusiata under RubberForest in Hainan

Abstract

In order to explore the reasons for continuous cropping obstacles of Dictyophora indusiata under rubber forest in Hainan province, pure microbial culture technology and BIOLO-ECO microplate were used to analyze the culturable microorganisms, functional microorganisms, functional diversity of microbial communities, physical and chemical properties of soil and enzyme activities in the soil covered by Dictyophora indusiata for different continuous cropping years. The results showed that with the increase of continuous cropping years, soil pH decreased, organic matter and total potassium content decreased significantly, and total nitrogen and total phosphorus content increased significantly; The total number of culturable microorganisms and the number of nitrogen fixing bacteria, aerobic cellulose decomposing bacteria, nitrite bacteria and denitrifying bacteria in the soil increased first and then decreased, reaching the peak in the first year of continuous cropping, showing a trend of transformation from “bacterial” to “fungal” as a whole. Soil sucrose activity decreased first and then increased, while urease and dehydrogenase activity increased first and then decreased. The AWCD values of soil microorganisms of Dictyophora indu-siata under different continuous cropping years were different, and the utilization degree and characteristics of different carbon sources were different. The Shannon index, Simpson index and Pielou index of soil microbial community were not significantly different, and the McIntosh index of soil microbial community in the first year of continuous cropping was significantly lowest. To sum up, the continuous cropping of Dictyophora indusiata under rubber forest affects the physical and chemical properties of the soil and the activity of soil enzyme, and the accumulation of “toxic and by-product” substances produced by the “autolysis” of Dictyophora indusiata affects the number and function of culturable microorganisms and functional microorganisms in the soil, as well as the functional characteristics of the soil microbial community. It can be seen that the change of soil “Micro-environment” may be the main reason for the continuous cropping obstacle of Dictyo-phora indusiata under rubber forest. Therefore, in order to improve the yield and quality of the continuous cropping Dictyophora indusiata under rubber forest, effectively regulate the quality of continuous cropping soil, it is particularly important to provide suitable understory environmental conditions.