Topdressing quick-acting fertilizer and spraying foliar fertilizer can improve winter wheat?

The weather is hot and cold this year. In many places, just a few days after it was hot, there was a severe cold in late spring. In fact, there is nothing wrong with a cold spring. Don't you come to so many games every year? Everyone is used to it.

But people are used to it, but crops are really not used to it. Recently, the cold spring has made many crops really "bitter". For example, peach blossoms, apricot blossoms, pear blossoms and cherry blossoms in many places are competing to open, and fruit trees show their most beautiful time. However, several sudden "late spring cold" directly led to the reduction of fruit trees, not only fruit trees, but also wheat. Unexpectedly, now that wheat is heading, after the "cold spring", wheat does not directly ear, has no seeds, or is semi-sown.

In fact, before and after Tomb-Sweeping Day, the fastest growing period of various plants was the jointing stage. When they try to grow up, their cold resistance and disease resistance naturally weaken. This "cold spring" undoubtedly added chaos to spring ploughing and added fuel to the flames.

In fact, at the beginning of spring ploughing this year, the weather was very hot, and farmers were not ready to add water and fertilize. Later, the cold spring followed, and I had to take remedial measures quickly. Topdressing foliar fertilizer has become the most common remedy. Topdressing foliar fertilizer has obvious advantages such as high nutrient utilization rate, faster nutrient absorption and transformation speed than root system and low cost, but can topdressing foliar fertilizer really remedy the loss of "late spring cold"? There's pressure in here. If the foliar fertilizer is not applied properly, it will not only be useless, but also cause crop phytotoxicity.

First of all, the application of foliar fertilizer needs to be targeted. There are many kinds of foliar fertilizers. When the base fertilizer is insufficient, foliar fertilizer mainly containing nitrogen, phosphorus and potassium should be selected, and when the base fertilizer is sufficient, foliar fertilizer containing trace elements should be selected.

Here, for example, the stem rot of tomatoes after rainy weather is related to potassium deficiency. Spraying potassium dihydrogen phosphate for 2-3 times within 15 days after tomato fruit setting. However, cotton's falling buds and bolls are different. Spraying boron fertilizer on cotton leaves for 2-3 times in bud stage will get a good effect of keeping buds and bolls.

Secondly, the application amount of foliar fertilizer. The more foliar fertilizer is applied, the wetter the page of the crop will be, and the longer it is wetted, the more nutrients it will absorb. However, it will be easier to burn the leaves, which means that too much fertilization will cause fertilizer loss. On the other hand, if the amount is insufficient, it will not increase the nutrients. This degree and quantity are difficult to control.

Because various crops have different requirements for fertilizer concentration. Take urea as an example. Generally, the concentration used in gramineous crops is 1.5%-2.0%. However, the concentrations of Chinese cabbage, Chinese cabbage and purple cabbage are low, controlled at 1.0%- 1.5%, and the concentrations of potatoes are even less, controlled at 0.5%-0.8%, and the concentrations of apples, pears and grapes in fruit trees are 0.5%.

Third, the place and time of fertilization. Although the name is foliar fertilizer, it can't be sprayed anytime and anywhere. If you don't grasp it well, it will be counterproductive.

For example, grain crops such as rice and wheat can be sprayed with foliar fertilizer at the filling stage, and fruits and vegetables can be sprayed with foliar fertilizer from the early flowering stage to the young fruit expansion stage. Nitrogen, phosphorus and potassium fertilizers are mostly concentrated in the middle growth period of crops, generally 75- 100 kg per mu, while trace elements are all in the late flowering period, generally 50-75 kg per mu.

For the spraying position, there are generally more pores on the back of the page than on the front, so the nutrient absorption on the back of spraying will be stronger and more effective than on the front, especially for fruit trees.

Finally, the timing of spraying foliar fertilizer is also very important.

It is not suitable to apply foliar fertilizer in sunny noon and windy weather, because in dry and windy environment, the fertilizer solution will evaporate quickly and the fertilizer will be lost. It is not good to choose early morning and rainy day, because rain and fog will reduce the concentration and affect the fertilization effect.

Experienced old farmers will choose to spray foliar fertilizer on windless cloudy days or sunny afternoons and evenings. If it rains heavily three hours after spraying foliar fertilizer, they have to wait until the weather clears, and then spray it again with the same dose in half.

It should also be noted that some crops have a layer of cuticle similar to protective film on their leaves, which greatly reduces the fertility of foliar fertilizer. Therefore, it is best to add a little neutral soapy water when fertilizing to reduce the surface tension of the solution and make it easier to absorb.