First, the greenhouse vegetable fertilization misunderstanding
1. Dry organic fertilizer. In order to facilitate the application, the vegetable farmers in the production often use manure and chicken manure to dry in the field and lose water. This practice can cause fly maggots to multiply, nitrogen volatilization, and nitrogen nutrients that lose fertilizer.
2. Calcium, magnesium and phosphorus are used as basic fertilizers on alkaline soil. Calcium, magnesium and phosphorus are weakly acidic fertilizers, insoluble in water, can be gradually absorbed by crop roots under weak acid conditions, and applied on alkaline soil, which is easy to cause physiological phosphorus deficiency in seedlings.
3. The superphosphate is applied as a top dressing. Phosphorus has little mobility in the soil, generally 0.5 cm at the application point, and the range of movement is 1 to 3 cm. It is difficult to reach the crop rhizosphere and thus cannot supplement the deficiency of phosphorus in the crop.
4. Water is sprayed immediately after the urea is applied. Urea is easily soluble in water, and it must be decomposed into the soil to be converted into ammonium bicarbonate. It is absorbed and utilized by crops. Water is immediately applied after application, which makes urea lose with water and reduces fertilizer efficiency.
5. Ammonium bicarbonate is applied with water. This method makes the fertilizer more in the water inlet, which causes the crop to grow in different conditions. In the afternoon, the shed temperature rises and the ammonia gas escapes from the soil, causing fat damage.
Second, shed greenhouse vegetable fertilization and efficiency
1. The organic fertilizer pile is used as the base fertilizer. In the end of July, at the Xiangyang site, 4000 kg of human feces, plus 100 kg of calcium, magnesium and phosphate fertilizers, 400 kg of crushed wheat straw (ç³ ), mixed and piled into braids, covered with shabby plastic cloth or shredded with grass mud for 30 days. It is a high-quality organic fertilizer used in greenhouses as a base fertilizer.
2. The superphosphate is concentrated and applied as a base fertilizer. Open the 8 cm deep ditch in the transplanting plant, and then cover the soil with 4~5 cm after the phosphorus fertilizer is removed. Then transplant the crop in the shallow ditch to shorten the distance between the phosphate fertilizer and the crop rhizosphere to make up for the weak point of phosphorus mobility.
3, urea early application of deep application and root application. According to the demand for fertilizer and water in the crop development stage, early application and deep application can increase the utilization rate of shallow application by 28%. The shed temperature is 7 days ahead of time at 15~20°C, and the shed temperature is 5 days ahead of 20~25°C. When the application is carried out, the 8~10cm deep ditch is opened, and the soil is tightly covered after the sprinkling. Watering according to the shed temperature from 5 days to 7 days, so that it has enough time in the soil to fully ammoniaize, in order to facilitate the absorption and utilization of crops. During the growth period of the crop, the leaf surface can be sprayed with 0.3% urea solution, once every 7 days, 100 kg per acre / 667 square meters, for 2 to 3 times.
4. Deep application of ammonium bicarbonate. Ammonium bicarbonate is an ideal quick-acting fertilizer for the production of winter warm greenhouse vegetables. It is rarely volatilized at a temperature of 20 °C. After being applied to the soil, it slowly releases nutrients for root absorption of the crop, even under the soil temperature of 5 °C. Decomposition is absorbed and utilized by crops. When topdressing, open a 10 cm deep ditch 8 to 10 cm from the root of the crop. After spreading, cover with soil. It can increase the fertilizer utilization rate by 10~30%, which can increase the yield by 10% compared with the shallow application, and increase the yield by 7.8% compared with the water application.