What are the main characteristics of iron fertilizer and boron fertilizer? What are the problems that should be paid attention to in use?

With the rise and development of modern chemical industry, all kinds of chemical fertilizers have come out one after another. Fertilizer is very important to increase the yield of crops, and the lack of fertilizer will affect the normal growth and development of crops. What are the main characteristics of iron fertilizer and boron fertilizer? What are the problems that should be paid attention to in use?

First, iron fertilizer:

Iron is a kind of trace element which is needed in the process of crop growth. The iron content of plants is generally 0.3% of dry weight, which is an essential element for plants to carry out photosynthesis. when plants are deficient in iron, chlorophyll cannot be synthesized and chlorosis occurs. In the aerobic respiration of plants, the indispensable cytochrome oxidase, catalase and peroxidase all contain ferric acid, so iron is also involved in the respiration of objects. In recent years, it has been found that the two components of nitrogenase contain iron, which indicates that iron also plays an important role in biological nitrogen fixation.

Iron is one of the most difficult elements to move in crops, such as iron deficiency, first of all, the young leaves lack green, the mesophyll turns yellow at the beginning of the green-deficient leaves, the veins are still green, then the leaves turn white, the veins turn yellow, and necrotic tissues such as scorched brown spots appear in the middle or tip of the leaves on both sides, until the leaves fall off at last, while the old leaves are still normal. Iron fertilizer is suitable for all kinds of crops, such as soybean, spinach, tomato, apple, camellia, peach and so on.

Ferrous sulfate (FeSO4 ·7H2O) is mainly used as iron fertilizer, which is a green crystal, commonly known as green alum, which contains about 19% iron, and ammonium ferrous sulfate [(NH4) 2SO4 ·FeSO4 ·6H2O], which contains about 14% iron.

Iron fertilizer is mainly used as base fertilizer or extra-root topdressing. When the iron fertilizer is used as the base fertilizer, the ferrous sulfate solution can be sprayed on the organic fertilizer, mixed evenly and then applied to the soil. For fruit trees, the surrounding trenches can be dug for ring application or strip application. When iron fertilizer is used for extra-root topdressing of crops, 0.75% Mel 1% ferrous sulfate solution can be used to spray crops; root injection can also be used for fruit trees, preferably during the sprouting of fruit trees in spring.

Due to the rapid conversion of ferrous sulfate into insoluble compounds in calcareous soil, it is usually mixed with organic fertilizer.

Second, boron fertilizer

Boron is not a structural component of crops, but it has a special effect on some important physiological processes of crops. It plays an important role in the movement of carbohydrates in crops, and is an indispensable component in the process of crop reproductive organ building. in addition, it has an important impact on crop photosynthesis and improving crop resistance.

The common characteristics of boron deficiency in crops are: underdeveloped root system, death of growth point, imperfect flower development, "flower but not fruit" in rape, and "bud but not flower" in some rape. Boron fertilizer is suitable for all kinds of crops and soils, especially in the soil with low boron content.

At present, the main varieties used as boron fertilizer are: boric acid (H2BO3), which contains 17% boron; borax (Na2B2O7 ·10H2O), which contains 11% boron; in addition, there are boron-containing compound fertilizer and boron-containing industrial waste residue. However, borax and boric acid are widely used, both of which are white crystals or powders, soluble in water and water-soluble boron fertilizer.

Boron fertilizer can be used as base fertilizer, seed fertilizer and topdressing fertilizer. When used as base fertilizer, it can be evenly mixed with nitrogen fertilizer and phosphate fertilizer, or applied separately, but pay attention to uniform application, so as to avoid toxicity caused by excessive local concentration. On boron deficient soil, 0.5-1 kg boron fertilizer per mu can be applied, and the fertilizer effect usually lasts for 3-5 years. For seed fertilizer, soak seeds with 0.1% borax or boric acid solution of 0.1% concentration for 6-12 hours, cereals and vegetables with 0.01% murl solution of 0.03%, rice with 0.1% solution and 0.4-1g borax or boric acid per kilogram of seed. For extra-root topdressing, 0.1% Mel 0.2% borax or boric acid solution can be sprayed, which is generally carried out in the crop from vegetative growth period to reproductive growth period, that is to say, before and after flowering.

In the application of boron fertilizer, we should pay attention to: the application amount should not be excessive, and the application should be uniform, and the types of crops must be taken into account.