The Characteristics Of Solar Greenhouse Soil In Different Planting Years And Study On Amendment To The Soil

The experiment studied the nutrient content, heavy metal, enzyme activities, microbial and physical and chemical properties of the soil in sunlight greenhouse with different planting years. Based on previous results, the soil in the greenhouse, which has been used for 9 years was amended with built-in straw bio reactor. In addition, the effects of the depth of the straw in the soil on solar greenhouse soil and growth, yield and the fruit quality of Summer Squash (Cucurbita pepo L.)were researched, so as to provide a theoretical basis and guidance for soil amendment and rapid repair of solar greenhouse.Study of soil physical and chemical properties in greenhouse with different planting years, the results were as follow:1. With prolonged cultivation in greenhouse, the nutrients in the soil of 0-20cm layer showed a gradually increasing trend. The content of the total amount of water-soluble salts, organic matter content, total nitrogen, alkali-hydrolyzable nitrogen, total phosphorus, available phosphorus and available potassium increased with the extend of the planting years, and the correlation to the cultivation age was significant.2. With prolonged cultivation in greenhouse, Cu, Mn, Ni, Zn, Pb, Cr, Cd, As, Hg content in the soil layer of 0-20cm showed a positive linear correlation to greenhouse planting years, and the correlation between Cu, Mn, Zn, Pb and planting years reached the extremely significant, but there is no significant correlation between Ni, Cr, Cd, Hg and planting years.3. With the increase of planting years, soil enzyme activities decreased in varying degrees in the greenhouse soil planted 12 years, of which the linear correlation between polyphenol oxidase, protease and planting years reached the extremely significant, linear correlation between urease, invertase and planting years reached significant, amylase, phosphatase, catalase and planting years correlation is not significant.4. With the increase of greenhouse cultivation age, the total number of soil microorganisms, bacteria, actinomycetes number and B/F ratio (the ratio of quantity of bacteria and fungi) have shown decreased after the first increase. The total microorganisms, bacteria and actinomycetes were highest in the soil of greenhouse used for nine years, followed by decreasing significantly.5. With the increase of planting years, pH showed an extremely negative significant correlation with planting years, and EC showed highly significant positive correlation with the planting years. When the planting year was within 9 years, the surface soil bulk density showed a descending trend with the increase of planting years, total porosity, capillary porosity, field capacity, aggregation structure is increased year by year, but then each index showed the opposite trend, indicating that soil quality declined.In the improvement of the application of different buried depths of straw bio reactor on greenhouse soil:1. In greenhouse soil with straw buried depth increased straw bio reactor can continue to increase the content of organic matter, significantly reduce soluble total salt, steady increase the content of total nitrogen, alkaline hydrolysis nitrogen, total phosphorus, available phosphorus, but buried 25cm deep to be able to achieve the routine level of application of fertilizer; the content of available potassium significantly increased with the straw buried depth increase.2. In greenhouse soil of different buried depths of straw bio reactor, the activities of polyphenol oxidase, invertase, urease, protease, amylase, catalase except to phosphatase was improved with the application of straw buried depth increase to different degrees. In greenhouse soil, polyphenol oxidase, invertase, protease, amylase, catalase activities increased significantly when the straw was buried above 25cm depth, but the enzyme activity difference in 25cm and 30cm depth were not significant.3. The number of bacteria, actinomycetes and fungi were increased significantly by application of straw bio reactor in greenhouse soil, but it did not increase significantly between buried 25cm deep and buried 30cm deep, microorganisms and the total B/F ratio (ratio of quantity of bacteria and fungi) did not increased markedly between buried 25cm deep and buried 30cm deep.4. After application of straw bio reactor in greenhouse soil, bulk density and EC (electrical conductivity) decreased, total porosity, capillary porosity and field capacity increased, pH value recovery. Overall, straw buried 25cm depth was the best.5. With the depth of buried increased, plant height, stem diameter, leaf number increased continuously, the difference reached significant when the straw buried depth of 25cm or more. Under the condition of application of straw bio reactor, dry matter content and vitamin C content, crude protein and total sugar content of the summer squash were all higher than the conventional fertilizer management, the difference between 20cm and above all reached very significant level. Only the use of buried application of 25cm and above treatment, in order to make the total yield is not less than that of the control, and in the treatment of application of straw buried depth of 25cm and depth of 30cm the total production of the summer squash was significantly higher than the control, but the difference of the total yield between the two treatment is not large, and considering the application of straw bio reactor with corn straw and bacteria, manpower, time and other cost factors, the optimal application of straw buried depth was 25cm.