Effect Of Continuous Cropping On Physicochemical Properties Of Soil And Growth, Physiological Metabolism Of Pepper

In recent years, greenhouse cultivation developed rapidly, but as the special soil environment of greenhouse, the soil showed progressive salinization, nutrient imbalances, crop root exudates and accumulation with the cropping years increased.Too much attachment of importance to labor productivity while ignoring land productivity, caused a direct result of the facility soil obstacles in continuous cropping, the phenomenon of declining occurred in production efficiency and product quality deterioration.Through the study of effect of continuous cropping on physicochemical properties of soil in jiangsu province,pepper cultivar ’Ningyan No.2’was chosen as experimental material with pot experiment research. We discussed the effect of continuous cropping soil on growth,physiological metabolism and the fruit quality of pepper, and the relief effect of application of soil improver on continuous cropping obstacles. Main research results were as follows:1. Soil organic matter and total N were significantly higher than the control, total P, K and available nutrient were enriched to varying degrees. The level of acidification and salinization had increased along with continuous cropping years. Continuous cropping years of the soil and all the indexes have higher correlation, and different factors have different correlations as well, between the soil pH value and EC value was the most significant.2. With continuous cropping years increased, the number of soil bacteria and actinomyces both showed the trend of declined first and then rose, but fungi with the increasing number of continuous rise gradually, and the microorganism quantity achieved maximum in the florescence of pepper. The activity of soil catalase and invertase with the continuous increase both showed the trend of declined first and then rose, the activity of urease was significantly higher than control, soil urease and invertase activities achieved maximum in the florescence of pepper, but catalase fell rapidly.3. The growth of pepper plants was restricted under continuous cropped soil, the activities of SOD, POD and CAT in leaves increased significantly, as well as the content of MDA and osmotic substances. There were concentration of metal ions, and decline of Ca2+for the overground parts of pepper.Continuous reduced Pn、Gs、Tr and Ci of pepper leaves, and with continuous cropping years increased, all showed the trend of declined first and then rose; Under the condition of continuous, the fruit quality of pepper decreased significantly, soluble solids, soluble protein and total sugar content were significantly lower than the control.4. After the application of soil improver, the number of soil bacteria rose significantly in the florescence of pepper, fungi and actinomyces quantity in the whole period were significantly reduced. The activity of sucrose significantly reduced in the fruit period of pepper,but urease activity increased, catalase activity had no significant change.The application of soil improver can dramatically reduce harmful fungi and actinomyces quantity of soil, it can provide enough nutrient for pepper growth, improve the activity of soil urease, and provided better soil environment for pepper.