Rational fertilization of greenhouse vegetables to improve fertilizer efficiency

Greenhouse vegetables are a high-yield, high-yield production method in a specific environment. However, the survey results show that many farmers think that as long as they apply more fertilizer, they can obtain high yields. Therefore, the fertilizer application amount is many times higher than normal. This not only causes waste of material resources and manpower, but also brings obvious negative effects on greenhouse production. influences. Therefore, fertilization of greenhouse vegetables must pay attention to reasonable application.

Unreasonable performance of fertilization

Organic fertilizer is applied at will. Some people think that the winter temperature is not high, you can apply organic fertilizer that is not fully decomposed. When you do not know that it is decomposed in the greenhouse, the organic fertilizer will produce calories burned, causing poor growth of vegetables. Some people often apply human excrement and chicken manure. It is dried and applied, resulting in a large loss of nitrogen volatilization.

When the ammonium carbonate is applied, it is applied with water, and as a result, the fertilizer concentration at the water inlet is high, and the crop growth is uneven. When the temperature rises, the ammonia gas escapes from the soil, and the lower leaves of the crop are smothered, causing fat damage.

The application of calcium magnesium phosphate fertilizer in alkaline vegetable fields can not solve the phosphorus absorption and utilization of crop seedlings. Because calcium magnesium phosphate is a weakly acidic fertilizer, it can only be applied to weakly acidic soils and gradually converted into water soluble phosphates to be absorbed by crops. Calcium, magnesium and phosphate fertilizers are applied in alkaline soils without applying superphosphate. Physiological deficiency of phosphorus.

Immediately after the urea is applied, the water is lost, and the urea is lost with water, which reduces the fertilizer efficiency. Because urea is an amide nitrogen fertilizer, it is easily soluble. After being applied to the soil, it usually takes 3-5 days to decompose to become ammonium bicarbonate. The vegetables are absorbed and utilized, and the water is wasted immediately after the application.

Excessive partial application of fertilizer, especially the presence of certain elements in chemical fertilizers, will cause antagonism between the elements, resulting in the lack of some fertilizer elements, thus affecting the normal growth and development of vegetables. Excessive application of fertilizer will not only cause the loss of fertilizer, pollute the water source, but also cause smoked seedlings in greenhouses, yellow leaves and roots, wilting, seedlings not long or mad.

Measures to improve fertilizer efficiency

The organic fertilizer is fully decomposed and applied. The cake fertilizer is used as the base fertilizer, and it must be applied after being impregnated with hot water or human excrement urine for 20-25 days before application. The chicken manure with higher salt content as the base fertilizer must be used after fermentation, and it is not suitable for long-term application, otherwise it will cause the alkali return of the soil and alkalinize the soil. Using straw as the base fertilizer, it is best to use it as a winter shed for 2-3 months before use. If the enzyme is added to the compost, the time for decomposing will take 40-50 days, so prepare early.

Switch to superphosphate and concentrate on the base fertilizer. Calcium superphosphate is an acidic phosphate fertilizer. It should be applied to the soil where the shed soil is alkaline. Generally, 8 cm deep trench is opened in the transplanting plant, and the soil is 4-5 cm after being sprinkled, and then the crop is transplanted in the shallow ditch to prevent phosphate fertilizer. A weakness that is easily fixed and has little mobility in the soil.

Carbonic acid should be applied deep. Ammonium bicarbonate is a physiological acid fertilizer. After application, it will increase the acidity of the soil and destroy the soil structure. Therefore, when the top dressing is applied, the 10 cm deep groove should be opened at 8-10 cm of the root of the crop. After the fertilizer is applied, the soil cover is tight, which not only prevents the volatile injury. Seedlings, and can increase the utilization rate by 10%-30%.

Urea is applied early and applied outside the roots. Urea application in the greenhouse should be applied in advance and deep application. The general requirement is that the shed temperature should be 7 days ahead of 15-20 °C; the shed temperature should be 5 days ahead of 20-25 °C. Open the 8-10 cm deep ditch when topdressing, immediately cover the soil after application, watering according to the shed temperature after 5-7 days, so that it has enough time in the soil to be ammoniated for crop absorption and utilization, 0.3% in the growing season. The urea solution is used for foliar spray fertilizer, once every 7 days, 75-100 kg of fertilizer solution per acre, 2-3 times in succession.

Eliminate the application of chlorine-containing compound fertilizer. Most vegetables are chlorine-free crops. The application of chlorine-containing compound fertilizers is likely to cause the growth of vegetable roots to be hindered, and the plants grow poorly, which can lead to dead seedlings in severe cases. Therefore, greenhouse vegetables advocate the application of sulfur-based compound fertilizer.