Changes of organic soil substrate properties with different cultivation years and their effects on cucumber growth in solar greenhouse

This paper studied the changes of organic soil substrate properties with increasing cultivation years and their effects on the cucumber growth in solar greenhouse.The results showed that with increasing cultivation years,the physical and chemical properties of organic soil substrate deteriorated,which was manifested in the increase of bulk density and the decrease of total porosity,pH,and available nutrient contents.The numbers of bacteria and actinomycetes in the substrate decreased with increasing cultivation years,while that of fungi was in reverse.The cucumber growth was also affected to a certain extent,manifesting in the decrease of plant height and leaf area,the decline of photosynthetic efficiency,and the decrease of yield and quality.It would be necessary to restore the fertility of organic soil substrate after 3-year cultivation.