Greenhouse vegetable planting technology

     From the perspective of most farmers who grow vegetables in greenhouses, the benefits of growing vegetables in greenhouses are relatively obvious. However, some farmers plant vegetables in greenhouses, and the effect is not satisfactory. In addition to the wrong variety of vegetables, the restriction of the "four hazards" is often an important factor in causing losses. The so-called "four hazards" are fertilizer damage, phytotoxicity, drought damage and continuous stubble obstacles.

       One, fertilizer damage. In fact, it is the harm of salt accumulation. The main reason is that partial application of chemical fertilizers or excessive fertilization makes the soil salinized. The problems that occur after fertilizer damage are that the first is to inhibit the development of vegetable roots, which weakens the function of water and fertilizer absorption; the second is that the soil solution concentration is too large, and the reverse osmosis phenomenon occurs in the vegetable plant, which leads to physiological wilting or leaf edge burnt; It is the danger of toxic gas; the fourth is the vegetable deficiency syndrome.

       2. Drug damage. There is obvious phytotoxicity, and the symptoms are obvious. There is hidden phytotoxicity, and the symptoms are latent or extended to the next vegetable. The reasons for the phytotoxicity are: first, the wrong kinds of pesticides are selected or the herbicides are misused; second, the application concentration is too high; third, the low-quality pesticides are purchased; fourth, the application is not avoided during the high temperature season. After the occurrence of phytotoxicity, some vegetable leaves quickly become chlorosis; some produce burnt spots and perforations; some leaves, flowers, fruits, or deformities; the most serious whole plants wither.

       3. Drought damage. It is one of the most critical factors restricting the development of greenhouse vegetables. The reasons for this are the improper site selection of vegetable greenhouses and the lack of water in the area; the second is that although there are water sources, the water quality is poor; the third is that the water is sufficient, but the ditches, canals, and irrigation and drainage facilities are not matched, and the water is difficult to attract. Drought damage not only affects the timely sowing of seedlings of vegetables, but also affects the normal growth of vegetables. At the same time, it brings great difficulties to the management of vegetables such as fertilization and spraying. The impact of drought sometimes exceeds fertilizer damage and phytotoxicity.

      Fourth, continuous stubble obstacles. That is, in the same greenhouse, the same type or the same vegetable is grown every year or season, and the output and product quality are declining year by year. The reasons for the obstacles are that the same or the same kind of vegetables prefer certain nutrient elements, which are prone to lack of nutrients if they are not supplemented in time; second, the accumulation of soil pathogenic bacteria causes diseases and causes dead seedlings, such as fusarium wilt and verticillium wilt; Third, the same vegetable root exudates can easily cause the soil microbial community structure to lose balance and cause soil aging. 

     First of all, we must choose a good shed site and improve the water system. Before determining the large shed, it is necessary to check whether the shed site has sufficient water sources and whether the water sources have been polluted? With sufficient water sources, ditches and canals must be opened to facilitate water diversion and drainage. Where conditions permit, a water supply faucet should be installed in each greenhouse. High standards should also be equipped with sprinkler irrigation facilities.

     Second, balanced fertilization should be used to promote the steady growth of vegetables. One is to apply fully decomposed organic farm manure all year round; the other is to apply refined organic fertilizers and high-energy organic fertilizers, such as Ye Meifeng, Guo Meifeng, etc.; the third is to change the partial application of nitrogen and phosphorus to reduce nitrogen, stabilize phosphorus, and increase potassium. Apply micro-fertilizers; fourthly, apply appropriate fertilizers in stages; fifthly, if fertilizer damage occurs in one day, spray a variety of active liquid fertilizers to alleviate the damage.

      Third, we must use medicines scientifically to ensure the safety of vegetables. One is the occurrence of minor phytotoxicity, and the method of strengthening fertilizer and water management can be used to restore the normal reproductive function of vegetables; the second is to choose the right pesticides, especially herbicides, to be used carefully; the third is to control the dosage and concentration of the pesticides and avoid them at the same time. Repeated use of one kind of pesticide; fourth, avoid mixing pesticides at will; fifth, avoid high temperature when applying the pesticide; sixth, the equipment that has been applied with herbicides must be cleaned before reuse.

      Fourth, it is necessary to rotate crops and stubble to adjust the vegetable cultivation environment. One is the susceptible vegetables of eggplants, tomatoes, and melons. It is necessary to plant other vegetable variet.