In the process of vegetable growth, in addition to the three major nutrients nitrogen, phosphorus and potassium, but also need some trace elements, are indispensable, otherwise it will become a barrier to high quality and high yield of vegetables. Therefore, in the production of vegetables, we must pay attention to the application of trace elements to supplement trace elements, then, how to apply fertilizer on vegetables? First, according to the use of different types of micro-fertilizers, in general, sensitive to boron and the need for large quantities, the application of boron fertilizer has a good effect of rape, cabbage, cabbage-type vegetables and clams, oysters, cauliflower, lettuce, radish, etc.; Leguminosae and cruciferous vegetables are particularly sensitive to earthworms, and the application of molybdenum fertilizer has a good effect of increasing yield; zinc is very sensitive to legume vegetables and tomatoes, potatoes and onions are also sensitive to zinc, and zinc fertilizer has a large effect; Manganese is more hawthorn, potato and legume vegetables; lettuce, onion, spinach, carrots are more sensitive to copper, the relative demand is also a little more; easily vulnerable to iron deficiency of potatoes, cauliflower, cabbage, etc.; All vegetables are effective on application. Second, according to the content of effective trace elements in soil, the lack of stubble supplementation is generally under the following circumstances, increasing the yield of micro-fertilizer is significant. Water-soluble boron content in soil is below 0.5 mg/kg; effective molybdenum content in soil is below 0.2 mg/kg; effective zinc content in acid soil is less than 1 mg/kg; or effective zinc content in calcareous soil is less than 0.5 mg/kg The content of reducing manganese in the calcareous soil is below 100 mg/kg or the replacement manganese content is less than 2 mg/kg, or the content of reducing manganese in the acidic soil is below 25 mg/kg; effective in acidic and neutral soils The copper content is less than 19 mg/kg, or the effective copper content in alkaline soil is less than 1 mg kg. (1) Suitable concentrations for spraying on vegetables are 0.1%-0.25% borax or boric acid solution, 0.02%-0.05% ammonium molybdate solution, 0.05%-0.1% zinc sulfate solution, 0.05 0.1% manganese sulfate Solution, 0.01%-0.02% copper sulfate solution, 0.5%-1% ferrous sulfate solution, 0.03%-0.1% rare earth nitrate solution. (2) Spraying times. Foliar spray fertilizer, with less fertilizer, spray once difficult to meet the needs of the whole fertility process, generally should be based on the length of the growing period of vegetable spray 2-4 times. Sensitive vegetables should be sprayed more and combine with seed treatment. (3) Spray amount of fertilizer leaves. Due to the size of crop growth, generally 30-75 kilograms of spray fertilizer per acre, limited to stems and leaves wet. (4) spray when selected. Should choose to spray on a cloudy day (or sunny afternoon without wind to dusk), to extend the moisturizing time of the fertilizer solution on the leaves of the vegetables as much as possible, increase absorption and improve the application effect of the foliage. (5) A reasonable mix. Spraying several kinds of trace fertilizers or mixing them with other fertilizers and pesticides will save labor. However, they should not be mixed and mixed as needed. At the same time, attention should be paid to the dual effects of fertilizer and drug efficacy. It is advisable to do a compatibility test before mixing. Take a small amount of fertilizer and a small amount of pesticide in the same container and observe it together. If no turbidity, sedimentation, and bubbles appear, etc. , indicating that they can be sprayed together. If any of the above phenomena occur, they cannot be mixed. Generally, all kinds of trace fertilizers cannot be mixed with alkaline fertilizers or alkaline pesticides.