Influence of Greenhouse Cultivation on Soil Chemical Properties and Microbial Community

The study was conducted to investigate the chemical properties and microbial community in greenhouse soil with different cultivation years in Kunming suburbs.The results showed that the content of available N,P,K increased and soil pH value decreased with the cultivation year increasing.The content of total salt and soil organic matter were increased first,decreased then,and increased again with the cultivation year increasing and reached the maximum value after 6-year cultivation.Soil microbe number in greenhouse soil was higher than that in open field soil.The amount of bacteria,actinomyces,total microbe and B/F in greenhouse soil increased firstly,and then decreased with the cultivation years increasing.Shannon-Wiener diversity index,Simpson diversity index,Shannon evenness index decreased and fungi number increased with the cultivation years.These results indicated that at the early year of alternating open field cultivation into greenhouse cultivation,soil ecological environment quality was high.After 6～8 years planting,deterioration of soil chemical characters such as soil salt content,available N,P,K content and pH value adversely affected the soil microbial flora imbalance and resulted in microbial diversity,evenness dropping significantly,the great decline of long-term productivity of soil,and the stability and sustainability of soil quality decreasing.