farmer friends can avoid the risk of element "fight" through scientific fertilization. there are seven specific measures.
1. balanced fertilization
partial or multiple application of simple fertilizers to crops not only causes waste of fertilizers, increases production costs, but also easily leads to the lack of other nutrients. in wheat, maize, rice and other grain crops, farmers often prefer to apply nitrogen fertilizer, resulting in crop growth or lodging. because of the antagonistic effect between nitrate and phosphate ions, more attention should be paid to increasing the application of phosphate fertilizer when applying nitrate nitrogen fertilizer. it is a typical antagonistic effect to induce crop zinc deficiency due to excessive application of phosphorus fertilizer when crop phosphorus is deficient. in cash crops such as fruit trees and vegetables, excessive application of potassium fertilizer often leads to magnesium and calcium deficiency in crops. when applying fertilizer, according to the structure of crop fertilizer requirement and the ability of soil fertilizer supply, it is necessary to keep the balance of nutrient elements.
2. applying special fertilizer
compared with simple fertilizer, the proportion of nutrient elements in special compound fertilizer or compound fertilizer for crops is more appropriate. therefore, special compound fertilizer should be the main fertilizer, supplemented by simple fertilizer. if there is no special fertilizer for crops, potassium-demanding crops such as fruit trees or vegetables harvested with tubers and tubers can be supplemented by adding potassium fertilizer on the basis of general compound fertilizer.
3. applying organic fertilizer
organic fertilizer is a kind of fertilizer with balanced nutrition. it contains not only a large number of medium and trace elements necessary for plants, but also abundant organic nutrients. after applying organic fertilizer to soil, it can effectively improve the physical and chemical condition and biological characteristics of the soil, ripen the soil, enhance the ability of soil fertilizer conservation, fertilizer supply and buffer, and create good soil conditions for crop growth.
at the same time, the rational application of organic fertilizer and chemical fertilizer can complement and promote each other, which is conducive to crop absorption, improve fertilizer use efficiency, buffer or reduce the antagonism between nutrients. qualified organic fertilizer products manufactured by regular manufacturers must be applied. the quality of organic fertilizer with incomplete fermentation and unknown source of raw materials is a big problem. for example, salt, hormones, antibiotics, heavy metals and escherichia coli in the product exceed the standard. after application, it is easy to burn roots by secondary fermentation near the root system, which causes root blackening, root decay, yellowing of leaves, defoliation, weakening of tree vigor and dead tree phenomenon.
4. rational selection of fertilizer forms
in recent years, domestic fertilizer manufacturers have invested a lot in the research and development of chelating agents and their products, and have the ability to independently develop and produce chelating nutrients. the marketing of chelated nutrients in china has greatly helped to increase crop yield. at present, the organic-inorganic liquid fertilizer made up of humic acid, amino acid, chitin and alginic acid on the domestic market has obvious effect on crops, and the quality of products produced by regular manufacturers can be comparable to that of similar imported products abroad. iron, zinc, manganese and copper are best used as chelating fertilizers, so that they can be applied with other elements, while avoiding antagonism between them.
5. changing fertilizer application
if zinc fertilizer and phosphorus fertilizer are mixed, it will inevitably produce "xiangke". therefore, phosphate fertilizer should be used as base fertilizer, zinc fertilizer should be used as topdressing fertilizer to avoid the application of phosphate fertilizer and zinc fertilizer together. nitrogen, phosphorus and potassium fertilizers should be mainly applied in rhizosphere. nitrogen and potassium fertilizers can be sprayed and phosphorus fertilizers can be concentrated. micronutrient fertilizer should be sprayed on the leaves and combined with root application according to the degree of deficiency. seed dressing, seed soaking and root dipping can also be used to limit trace elements to a smaller range of roots and try not to contact with large amounts of elements.
6. fertilizing according to soil characteristics
in potassium-deficient sandy soil, nitrogen fertilizer and potassium fertilizer should be applied together, but potassium fertilizer should not be applied too much at one time, because potassium ion can also have an antagonistic effect on the absorption of calcium, magnesium and ammonium, which will lead to crop calcium and magnesium deficiency. nitrogen fertilizer should not be applied too much on acidic soil, otherwise it will be difficult for crops to absorb calcium ions when the concentration of ammonium ions is high. bitter pox disease occurs in some apple producing areas, which is due to calcium deficiency caused by excessive application of nitrogen fertilizer.
7. soil improvement
by improving the physical and chemical properties of soil, the suitable environment for crop growth was constructed. farmers like to use lime on acid soil to improve the soil. however, lime shall not be applied in excess or continuously. if lime is used excessively, it may induce crop boron deficiency, magnesium deficiency and phosphorus deficiency, which often occurs in fruit trees (such as oranges, bananas), vegetables (such as peppers, tomatoes, cucumbers) and other crops (such as cotton, rape). for the poor acid red soil in southern china, the application of biochar (mainly made from crop straw) can improve the soil in some places where conditions permit. at the same time, biochar can also enhance soil organic matter, improve soil structure, activate nutrient separators, adsorb toxic metal ions and so on. it can not only increase crop yield and quality, but also reduce nutrient leaching and improve nutrient utilization.