Celery suitable for more nitrogen fertilizer, but not topdressing urea. The celery needs a lot of facilities to produce vegetables during the whole growth period, which has the advantages of high economic benefit and annual supply, and is therefore favored by large vegetable farmers. However, in some areas where the development facilities were cultivated earlier, due to the high salt content of the soil, the emergence of vegetables was often uneven or the wilting of yellowing occurred after planting, which seriously affected the vegetable production efficiency. The reasons for the increase of soil salt concentration in greenhouse vegetables mainly include the following aspects: 1. The greenhouse is a closed environment. It is not affected by rainfall. The soil moisture moves downwards. The fertilizer remaining in the soil is hardly lost. At the same time, the water lifting movement is relatively strong, thereby strengthening the accumulation of salt to the soil surface. , so that the salt concentration in the plough layer rises. 2. The amount of fertilizer applied to greenhouse vegetables generally exceeds that of open fields, and some of them are even 4 to 6 times higher. In addition to the absorption of some of these fertilizers into vegetables, large amounts of fertilizers remain in the soil, resulting in the accumulation of salts. 3. Other cultivation measures such as shallow ploughing, soil watering, and surface fertilization can aggravate the concentration of salt to the topsoil. The prevention of soil salt damage in greenhouse vegetables can take the following five measures: 1, formula fertilization. According to the amount of fertilizer required for fertilizers and the fertilizer utilization rate of the vegetables, the fertilizer is planned to be used in small quantities to prevent excessive fertilization. At the same time, pay attention to the type of fertilizer, and be cautious in using chlorinated fertilizers with strong salinity in the soil. 2, cover cultivation. Soil cover is used to reduce moisture evaporation. Such as mulch, straw and other coverage have a certain effect of inhibiting salt. 3, irrigation washing salt. For soils with high salinity, it is best to irrigate the vegetables before transplanting them. Especially in the season when the temperature is high, it takes about 10 days to irrigate the water. 4. Choose a salt-tolerant vegetable. According to experts' observation on some vegetables, the salt tolerant order from strong to weak is: broccoli, cabbage lettuce, spinach, eggplant, celery, tomatoes, bell pepper, cucumber, and strawberry has the lowest salt tolerance. Therefore, in soil with high salinity, vegetables with strong salt tolerance should be planted to prevent salt damage. 5, implementation of facilities in the dry and dry rotation. After the greenhouse vegetable is grown for a period of time, aquatic vegetables such as water spinach, white peony, sorghum, arrowroot, wet cress, etc. can be planted in the greenhouse, and the soil salt content in the plough layer can be effectively reduced through long-term irrigation and cultivation. Home Safe ,Home Safe Box,Home Safe Box Fireproof,Fireproof Waterproofhome Safe Box Ningbo Zhaomu Electronic Commerce Co., Ltd. , https://www.bofonhome.com