(1) Basic knowledge of chemical fertilizers
Chemical fertilizer: Fertilizer made by chemical and/or physical methods that contains one or several nutrients needed for the growth of crops. Also called inorganic fertilizers, they include nitrogen fertilizers, phosphate fertilizers, potassium fertilizers, micro-fertilizers, compound fertilizers, etc. They are not edible. The characteristics of chemical fertilizers include simple ingredients, high nutrient content, fast fertilizer effect, and strong fertilizing power. Some fertilizers have acid-base reactions; they generally do not contain organic matter and have no effect in soil improvement and fertilization. There are many types of chemical fertilizers, and their properties and application methods vary greatly.
(2) Why do we need to know fertilizer knowledge when using chemical fertilizers?
Fertilizer is food for plants and the material basis for agricultural production. Rational application of fertilizers plays an important role in improving crop yield per unit area and quality of agricultural products, and continuously enhancing soil fertility. Different types of fertilizers have different characteristics, which requires us to understand the basic characteristics of various fertilizers when applying fertilizers so that the fertilizers can be fully and efficiently utilized.
We know that chemical fertilizers have the characteristics of high nutrient content, quick effect, and single nutrient. For example, ammonium bicarbonate contains 17% nitrogen, which is 20 times higher than the nitrogen content in human urine. Ammonium nitrate contains 34% pure nitrogen, while urea, liquid nitrogen, etc. contain even higher nitrogen contents. At the same time, chemical fertilizers can be divided into quick-acting and slow-acting ones, and the usage methods and application periods also vary accordingly.
(3) Classification according to fertilizer efficiency
(1)Quick-acting fertilizer
After this kind of chemical fertilizer is applied to the soil, it is immediately dissolved in the soil solution and absorbed by the crops, and the effect is very fast. Most types of nitrogen fertilizers, such as calcium phosphate in phosphate fertilizers and potassium sulfate and potassium chloride in potassium fertilizers, are all quick-acting chemical fertilizers. Quick-acting chemical fertilizers are generally used as top dressing and can also be used as base fertilizers.
(2) Slow-release fertilizer
Also known as long-acting fertilizers and slow-release fertilizers, the compounds or physical states of these fertilizer nutrients can be slowly released over a period of time for continuous absorption and utilization by plants. That is, after these nutrients are applied to the soil, they are difficult to be absorbed by the soil solution immediately. Dissolution requires a short period of transformation before the fertilizer effect can be seen, but the fertilizer effect is relatively long-lasting. The release of nutrients in the fertilizer is entirely determined by natural factors and is not controlled by humans. Among them, long-acting ammonium bicarbonate is added with ammonia stabilizer in the ammonium bicarbonate production system, which extends the fertilizer efficiency period from 30-45 days to 90-110 days, and increases the nitrogen utilization rate from 25% to 35%. Slow-release fertilizers are often used as base fertilizers.
(3)Controlled release fertilizer
Controlled release fertilizers are slow-acting fertilizers, which means that the nutrient release rate, quantity and time of the fertilizer are artificially designed. It is a type of specialized fertilizer whose nutrient release dynamics are controlled to match the nutrient needs of the crop during the growth period. . For example, 50 days for vegetables, 100 days for rice, 300 days for bananas, etc. The nutrients required for each growth stage (seedling stage, development stage, maturity stage) are different. Factors controlling nutrient release are generally affected by soil moisture, temperature, pH, etc. The easiest way to control release is the coating method. Different coating materials, coating thickness and film opening ratio can be selected to control the release rate.
Post time: Aug-06-2024
