Winter vegetable fertilizer application requires "four attentions"

Pay attention to the selection of quick-acting fertilizer. In winter, the temperature is low, the microbial activity is weakened, and the fertilizers that need to be transformed are slow, while the winter crops need to be fully fertilized. The solution to the conflict is to apply quick-acting fertilizers. Nitrogen fertilizer can use ammonium bicarbonate; phosphate fertilizer should use superphosphate as much as possible; potassium fertilizer can choose potassium chloride (but potato, tomato, etc. should be selected in the middle and late growth period of potassium chloride); application of compound fertilizer can choose 45% ternary Compound fertilizer; farmyard manure can be used for decomposed human excrement. This is because, compared with urea, ammonium bicarbonate belongs to ammonium nitrogen fertilizer, which can be directly absorbed and utilized by crops after being applied to soil, unlike urea (which belongs to ammonium amide, which needs urease secreted by urea bacteria in the soil). The ability to convert to ammonium nitrogen for root absorption) is affected by low temperature and slow to affect crop growth. Superphosphate contains 14%-20% of effective phosphorus pentoxide (80%-95% of which is soluble in water), which is a water-soluble quick-acting phosphate fertilizer, and its fertilizer efficiency is faster than that of calcium magnesium phosphate. However, it is best to pay attention to the greenhouse vegetables without the use of ammonium bicarbonate, and switch to 45% ternary compound fertilizer to prevent ammonia damage. Phosphorus is easily absorbed and solidified by the soil. When used as a top dressing, it can be used in the super-calcium leaching solution (5%-10% concentration) or in the early stage of the crop.

Cruciferous crops pay attention to the application of boron fertilizer in winter crops, cruciferous crops account for a large proportion, such as cabbage, cabbage, radish, rapeseed, etc., these crops are particularly sensitive to boron. At the same time, celery, wheat, carrots, etc. are also sensitive to boron. Boron deficiency is not only severely affected by reproductive growth, but also vegetative growth hits the wall, the ability to resist cold is reduced, and heart rot is easily induced.

Application method: 1 The basic fertilizer boron fertilizer has the best effect on the soil with moderate or severe boron deficiency; 0.5-0.75 kg of borax per mu can be mixed with dry fine soil or organic fertilizer, then ditch strip application or hole application; Or mix with nitrogen, phosphorus, potassium and other fertilizers; do not directly contact the seeds (live) or seedlings (transplanting), so as not to affect the growth of germination, emergence and roots, seedlings; The amount of application should not be too large; if the amount of borax applied per mu is more than 2.5 kg, the emergence rate will drop, and even the dead seedlings will be reduced. 2 to solve the seed soaking should use borax or boric acid, usually first dissolve the borax with hot water of 40 ° C; add cold water to 0.01% - 0.03% of borax or boric acid solution; pour the seeds into the solution, soak for 6-8 hours The seed and liquid ratio is 1:1, and it can be sown after being taken out and dried. 3 external top dressing (foliar spray) with 0.1% -0.25% borax or boric acid solution, spray 40-80 kg solution per acre; 6-7 days once, even spray 2-3 times; leaf surface Spraying in the afternoon is good, spray to the surface of the leaves with fog drops; if it rains within 6 hours after spraying, it should be sprayed once.

Before low temperature, pay attention to the application of wax fertilizer to apply the wax fertilizer, which can increase the ground temperature by 2 °C - 3 °C, and increase the potassium content of the crop cells, thereby increasing the water holding capacity of the cells, making the cells less susceptible to freezing at low temperatures and strengthening the cold resistance; Fertilizer must vary from crop to crop. The rapeseed should be mixed with the fertilizer and the phosphate fertilizer. The per capita a field is applied to the rapeseed line with about 1500 kg, and the soil is combined with the soil, and it is applied from late December to early January. The early-maturing rapeseed variety is spring, early. It should be applied earlier than late-maturing rapeseed varieties; wheat should be applied in the middle and late December, and strong seedlings should be mixed with soil, while weak and late-maturing wheat should be mixed with appropriate amount of phosphate fertilizer. Each acre of field application or application of soil fertilization 2500 kg or so; perennial crops application of fertilization should account for 50% of the annual fertilization amount, 5000 kg per mu of soil and 2,500 kg of pig and cow manure, and It is better to apply before the snow after the frost.

The greenhouse vegetable and raisin is resistant to the large amount of nitrate accumulated in the nitrate itself, but it is easy to be converted into nitrite. The nitrite is easy to replace the iron in the human blood and cause blood poisoning. Nitrite and amines can form a strong carcinogen, nitrosamine, which causes cancers such as stomach and intestines. In winter, there are more meteorological conditions of low temperature and low light, and greenhouse vegetables are more likely to cause a large accumulation of nitrates, especially leafy vegetables and root vegetables. The amount of nitrogen fertilizer should be strictly controlled, and phosphorus and potassium fertilizer should be added. In particular, nitrate nitrogen fertilizers such as ammonium nitrate and potassium nitrate cannot be applied.