What is Fertigation?

Fertilization refers to agricultural technical measures in which fertilizer is applied to the soil or sprayed on plants to provide nutrients required by plants and to maintain and improve soil fertility. The main purpose of fertilization is to increase crop yield, improve crop quality, improve fertility and improve economic efficiency. Therefore, rational and scientific fertilization is one of the main means to ensure food security and maintain sustainable agricultural development. The main basis of fertilization is the soil fertility level, crop type, target yield, climate and environment, and fertilizer characteristics. Therefore, the appropriate fertilizer is selected, the required fertilizer amount is estimated, and the fertilization time and pattern are determined. According to the different fertilization time, it can be divided into base fertilizer and topdressing, and according to different fertilization modes, it can be divided into spreading, flushing, acupoint, stripping, etc .; spreading and flushing are beneficial to the diffusion of nutrients, easy to apply, but nutrient Large loss and low utilization rate; hole and strip application have less nutrient loss and high utilization rate, but consume certain mechanical energy; with the development of modern precision agriculture, precision fertilization has also developed rapidly and will become an important Fertilization pattern. ^[1]

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Soil must be considered for fertilization. First, fertilization is needed only when the soil is in short supply of a certain nutrient, and it is not necessary to apply all necessary elements to the soil. Because most nutrients provide sufficient nutrients, otherwise it will cause waste and even cause crop poisoning. This is sometimes overlooked. Secondly, a series of changes will occur after the fertilizer is applied to the soil, which will affect the effect of the fertilizer to varying degrees. Regardless of the soil, there is no real rational fertilization. For example, the application of nitrate nitrogen fertilizer in paddy fields will inevitably reduce fertilizer efficiency.

Irrational fertilization is usually caused by irrational fertilization quantity, fertilization period, and fertilization method. Common phenomena are:

(1) Apply fertilizer shallowly or superficially. Fertilizers are volatile, lost or difficult to reach the roots of crops, which is not conducive to crop absorption, resulting in low fertilizer utilization. Fertilizer should be applied 16 ~ 26cm below the seed or plant side.

(2) Application of chlorinated fertilizer. The compound fertilizer produced by using ammonium chloride and potassium chloride is called double chlorine fertilizer, which contains about 30% chlorine and is easy to burn seedlings. Chlorine-free fertilizers should not be used on saline-alkali soils and chlorine-sensitive crops. Excessive application of potassium chloride to leaf (stem) vegetables will not only cause the vegetables to be not tender and rich in fiber, but also make the vegetables taste bitter, poor in taste and low in efficiency. Urine-based compound fertilizers have high nitrogen content and biuret content, and are easy to burn seedlings. Pay attention to watering and fertilization depth.

(3) Improper application of chemical fertilizers to crops may cause fertilizer damage, burnt seedlings, and plant wilting. For example, excessive application of chemical fertilizer at one time or insufficient soil moisture after fertilization will cause the soil solution concentration to be too high, it will be difficult for the crop roots to absorb water, and the plants will wither or even die. Excessive application of nitrogen fertilizers results in a large amount of ammonia or ammonium ions in the soil. On the one hand, ammonia volatilizes and meets droplets in the air to form small alkaline water droplets, which burn the crops and cause scorched spots on the leaves. The soil is easy to nitrate, and is transformed into ammonium nitrite under the action of nitrosating bacteria. Nitrogen dioxide gasification will poison the crop, and irregular water stain-like patches will appear on the crop leaves, and the veins will gradually turn white. In addition, when there is too much ammonium nitrogen in the soil, plants will absorb too much ammonia, causing ammonia poisoning.

(4) Excessive use of a certain nutrient element will not only cause damage to the crop, but also hinder the absorption of other nutrients by the crop, causing a deficiency. For example, excessive nitrogen application will cause calcium deficiency; excessive nitrate nitrogen will cause molybdenum deficiency and chlorosis; excessive potassium will reduce the effectiveness of calcium, magnesium, and boron; excessive phosphorus will reduce the effectiveness of calcium, zinc, and boron.

(5) Fresh human feces should not be applied directly to vegetables. Fresh human feces contain a large amount of germs, toxins, and parasite eggs. If they are applied directly without being cooked, they will contaminate vegetables and be easily contagious. They can only be applied after high-temperature stacking fermentation or harmless treatment. Unrotten animal and poultry manure will produce a large amount of harmful gases such as hydrogen sulfide during the decay process, which will easily suffocate the vegetable seeds with hypoxia; and generate a lot of heat, which will easily burn the vegetable seeds or cause root rot disease, which is not conducive to vegetable seed germination Grow.

In order to prevent the occurrence of fertilizer damage, reasonable fertilization should be paid attention to in production. The first is to increase the application of organic fertilizer to improve soil buffering capacity. The second is to apply chemical fertilizers in accordance with regulations. According to the soil nutrient level and the demand of crops for nutrient elements, fertilize reasonably, do not increase the fertilization amount at will, and apply topdressing to master the principle of light fertilizer and frequent application. The third is full-layer fertilization. When the same amount of chemical fertilizer is applied locally, it often causes a sharp increase in the local soil solution concentration and damages the crop root system. Instead, full-layer fertilization can be used to evenly distribute the fertilizer throughout the cultivated layer and protect the crop from harm.

The summer is hot and rainy, and the sun is abundant, which is beneficial to the photosynthesis of the leaves. It is a period of rapid growth of crops and a period of maximum efficiency of crop nutrition. Farmers in some places like to use the nitrogen fertilizer during the whole growth period of the crop as a base fertilizer for one-time application at the time of sowing. The nitrogen fertilizer stays in the soil for a long time, and the crops grow slowly and absorb less in the early stage. As a result, the nitrogen fertilizer is lost, waiting for high temperature and rain. When the season comes, the crop enters a fast-growing stage and requires a lot of nutrients. At this time, nitrogen fertilizer has been applied to the soil, and part of it has been lost. Insufficient nutrient supply will cause de-fertilization of crop growth in the later stage, reducing yield and quality. Improving crop yields plays a larger role.

Fertilization

Common fertilizers include urea, ammonium sulfate, and ammonium nitrate. They are the main sources of available nitrogen and are one of the main elements for plant protein synthesis.

Method: When used, it can be formulated into a solution with a concentration of less than 0.1%. Too much will cause the plant to dehydrate and die.

Fertilizing

Superphosphate and phosphate rock are one of the sources of phosphorus, which helps flower bud differentiation, strengthens the root system of the plant, and increases the cold resistance of the plant. Their fertilizer effect is slower.

Method: It is rarely used in potted flowers. The phosphorus is often obtained by applying compound phosphate fertilizer in flower cultivation. When superphosphate is used for topdressing, first add 50-100 times water, soak it for a day and night, and take the clear solution above to water.

Fertilization

Method: Potassium is the main element of plant ash. Potassium can enhance the resistance and disease resistance of plants and is one of the indispensable elements of plants. Common potassium fertilizers include potassium chloride and potassium sulfate, which can be formulated into a solution with a concentration lower than 0.1% when used.

Fertilizing compound fertilizer

There are many types of compound fertilizers, which refer to chemical fertilizers that contain three elements of nitrogen, phosphorus, and potassium, or two of them. Common potassium dihydrogen phosphate, Russian compound fertilizer, diammonium, etc. can be formulated into an aqueous solution with a concentration of 0.1 | -0.2% when topdressed. Various fertilizer manufacturers also introduced some special fertilizers for flowers.

Method: Special fertilizers for leaf-seeing flowers, special fertilizers for woody flowers, special fertilizers for herbaceous flowers, special fertilizers for acid soil flowers, special fertilizers for cactus and special fertilizers for bonsai, etc., are available in the flower market, and you can use them according to the instructions.

Fertilizing trace elements

Trace elements need to be used in a small amount during plant development. Generally, the trace elements contained in the soil are sufficient for the growth of flower plants, but some plants show chlorosis and variegated phenomena due to lack of trace elements during the growth process.

Methods: For example, iron deficiency in flowers showed chlorosis; boron deficiency showed apical buds stopped growing, plants became dwarfed, and leaf shape became smaller; zinc deficiency showed chlorosis and leaflet disease. Application concentration: boron fertilizer spraying concentration is 0.1% -0.25%, zinc fertilizer spraying concentration is 0.05-0.2%, molybdenum fertilizer spraying is 0.02% -0.05%, iron fertilizer spraying concentration is 0.2% -0.5%, Spraying concentration of manganese fertilizer is 0.05% -0.1%