What fertilization misconceptions do growers not know about?
If you go to the countryside and ask a farmer uncle, saying “Your way of fertilizing is wrong”, it will inevitably cause a ‘huge uproar’. But precisely because farmers trust their own farming experience, they instead harm their own crops. So what fertilization misconceptions do growers not know about?
21 fertilization misconceptions:
1. Double-chloride fertilizer
A compound fertilizer produced from ammonium chloride and potassium chloride is called double-chloride fertilizer, containing about 30% chlorine; it easily burns seedlings, so it must be watered promptly. Chlorine-containing fertilizers cannot be applied to saline-alkali soil or to chlorine-sensitive crops. Excessive application of potassium chloride and the like to leaf (stem) vegetables not only makes the vegetables less tender with more fiber, but also makes them taste bitter, with poor mouthfeel and low returns. Urea-based compound fertilizer is high in nitrogen, and biuret also contains slightly high nitrogen, so it easily burns seedlings; pay attention to watering and fertilization depth.
2. Applying only base fertilizer, without topdressing
Many users, fearing trouble, stop topdressing after applying base fertilizer. This fertilization method is unscientific. Crops have a relatively low nutrient demand in the early stage, and after sufficient base fertilizer is applied, it can indeed guarantee the crop's nutrient demand for a long time, but even for some fertilizers with relatively strong residual effect, the duration of their fertilizer effect is limited. Especially for sandy loam soil with poor fertilizer and water retention capacity, failure to topdress in time more easily causes nutrient deficiency. Therefore, for crops with a growth period exceeding 2 months, appropriate topdressing should be carried out to ensure the crop's nutrient demand during the vigorous growth period.
3. Same formula, same dosage, same effect
The reasoning is very simple: the main difference between a fat person and a thin person is not how much they eat, but how much they absorb. The same goes for fertilizers: with the same formula and the same dosage, due to the product itself there will be an obvious difference in nutrient utilization rate. This is why some products with low total nutrients can have a better effect than products with high nutrients.
4. After using compound fertilizer, no other fertilizer is needed
Some users believe that after applying compound fertilizer, there is no need to apply other fertilizers. This is wrong. Generally, compound fertilizers commonly contain only nitrogen, phosphorus and potassium, with a small number of varieties containing zinc and boron. If timely supplementation of effective medium and trace nutrient elements and organic activated nutrients is neglected, it will likewise have a serious impact on crop quality and yield, and returns will decline.
5. Fertilizing fruit trees by looking at the flowers
Whether a fruit tree has many or few flowers largely depends on tree vigor. To make the fruit tree differentiate more flower buds and set more fruit the next year, sufficient fertilizer should be applied the previous year; especially post-harvest fertilization is very important: because after picking the fruit the tree is greatly weakened, and at this time nutrients should be supplemented in time to restore the tree's vigor, enhance its resistance, and ensure its production capacity the next year.
Some people like to apply winter fertilizer. Although it is useful, it is not the best timing, because the most important part for the fruit tree to absorb nutrients is the roots. When winter sets in, the tree's root system is almost in a dormant state, and its ability to absorb nutrients is very weak. The best time for fertilizing fruit trees is after fruit picking and before leaf fall. The most direct result of fertilizing by looking at the flowers is causing an obvious alternate bearing phenomenon in fruit trees.
6. The faster the fertilizer dissolves, the better
Crops need nutrients just like people do, every day, and their absorption amount is also limited. If it dissolves quickly and the crop cannot absorb it, it is also a waste. This is also the main reason why some products add slow-release agents: to ensure the crop's nutrient needs throughout the whole process. However, chemical fertilizers with slow-release agents added are not suitable as topdressing, because if the nutrient release rate cannot keep up with the crop's nutrient demand, the crop will show nutrient deficiency in the early stage.
7. High price = high cost
Because fertilizer belongs to the category of means of production, not direct consumer goods, the basis for analyzing whether the cost is high or low is not price but the input-output ratio. If under the same dosage or the same input, whichever product brings higher returns and higher yield, that product's cost is lower.
8. Favoring nitrogen fertilizer in topdressing
Many users favor nitrogen fertilizers such as ammonium bicarbonate and urea when topdressing. Although this produces an obvious effect on crop growth, it cannot bring users a yield increase, because for the crop's early growth, nitrogen is very important, but as the crop grows, the demand for phosphorus, potassium, trace elements and organic nutrients becomes higher and higher, while the need for nitrogen instead decreases. Favoring nitrogen fertilizer will only make the crop grow excessively, causing an imbalance between vegetative growth and reproductive growth, with fewer fruits or delayed maturity with excessive vegetative growth, and poor taste.
9. If yield does not go up, the fertilizer is bad
A small number of users believe that if yield does not go up it is the fertilizer's fault. In fact, there are many reasons why yield does not go up, such as weather, soil quality, fertilization methods, pests, diseases and weeds, fertilizer selection, seeds, pesticides and field management, etc. It should be examined from all aspects; whether the fertilizer is good or bad is only one of the factors.
10. The closer fertilization is to the plant stem, the more easily the fertilizer is absorbed
This is a fairly common phenomenon in rural areas, and this fertilization method poses relatively great harm. Because the part of the plant that absorbs nutrients is the root hair zone, the plant stem and roots (except the root hair zone) absorb very few or no nutrients. The closer fertilization is to the plant stem (except at the seedling stage), the farther the fertilizer is from the plant's nutrient absorption site, and therefore the less easily it is absorbed. If too much fertilizer is applied and the concentration is too high, it is also prone to causing “seedling burn”.
Therefore, when fertilizing, the fertilization position should be determined according to the aboveground growth of the plant and the underground root growth, to ensure the fertilization effect. Some fruit growers likewise often apply fertilizer concentrated in trenches and holes when fertilizing, which is wrong. Because fruit trees absorb fertilizer in two ways: one is completed by their own power, and the other is completed by soil solution osmosis. When the solution concentration in the root environment is high, reverse osmosis occurs, causing root burn. The correct method is to mix organic fertilizer with soil evenly and then apply it in the trenches and holes. For water-soluble fertilizers, it is best to mix with soil or dilute before irrigating, or irrigate immediately after fertilization, to avoid root burn.
11. Valuing chemical fertilizers while underestimating the role of organic fertilizers
China's traditional fertilization refers to organic fertilizers, and the use of organic fertilizers has a history of over a thousand years. Organic fertilizers provide very high nutritional content for fruit trees, but they are also very inconvenient to use. In recent years, the country has developed high-yield and high-efficiency chemical fertilizers that can achieve yield increases with immediate results. Therefore, some fruit growers ignore the role of organic fertilizers, reducing their application amount year by year, and even individual orchards no longer apply organic fertilizers, relying solely on chemical fertilizers to maintain yield.
This causes soil compaction and a decline in fruit quality. In addition, most orchards are built on sloping land, and the large amount of transport labor and effort is also one of the reasons for the decline in fruit quality. The role of organic fertilizers in fruit tree production is irreplaceable, and the application of organic fertilizers to fruit trees must be taken seriously.
12. Fertilizing only after crops show signs of nutrient deficiency
After fertilizer is applied, it takes 3-5 days in paddy fields before it can be absorbed and utilized by crops, and generally 5-7 days in dry land before it can be absorbed and utilized. Therefore, if fertilization is carried out only after crops show signs of nutrient deficiency, it will prolong the period of crop nutrient deficiency and cause yield reduction. So fertilization work should be carried out according to the fertilizer requirement characteristics of the crops: fertilize 5-7 days in advance for paddy fields, and 8-10 days in advance for dry land.
At the same time, the nutrient absorption of crops is also related to light, temperature, water, and fertilization methods (such as dry application, drenching application, foliar topdressing, etc.). Strong light, high temperature and sufficient water accelerate the crop's nutrient absorption; on the contrary, absorption slows down. Foliar topdressing, because nutrients are directly absorbed by the leaves, takes effect quickly and can be applied later, but the concentration must be low to prevent leaf damage. Drenching application allows fertilizer to directly penetrate into the plant roots, takes effect relatively quickly, and can also be applied appropriately later. Dry application has a slow fertilizer effect, so it should be applied early.
13. As long as enough fertilizer is applied, high yield can be obtained
The types and amounts of nutrients required by various crops during the whole growth period and at different growth stages are all different. If fertilization is not carried out according to the fertilizer requirement characteristics of the crops, first, it will cause crops to show nutrient deficiency symptoms and a decline in stress resistance and disease resistance, resulting in reduced yield and quality decline; second, it will cause nutrients that some crops need little of or basically do not absorb to remain or be lost, causing fertilizer waste. Therefore, the type and amount of fertilization should be determined according to the growth characteristics of the plants, to give full play to the fertilizer effect.
14. The more fertilizer applied, the higher the benefit
According to the law of diminishing returns, after fertilization reaches a certain amount, the input-output ratio declines and the benefit decreases. If too much fertilizer is applied, it will cause yield reduction. Therefore, according to the fertilizer requirement characteristics of the crop throughout the growth period, soil fertility, crop planting density, etc., and on the principle of supplying sufficient but not wasting, the best fertilization plan should be found for fertilization, to give full play to the fertilizer effect and increase economic benefits.
15. As long as the crop's vegetative growth is good, high yield can be obtained
Crop growth includes two stages, vegetative growth and reproductive growth (except for leafy vegetables and fleshy stem crops). Applying sufficient nitrogen fertilizer in the early growth stage can promote vegetative growth, but if nitrogen fertilizer is favored during the reproductive growth stage, it will cause the crop to stay green, affect reproductive growth, hinder the transformation of nutrients, and instead reduce yield and lower quality. Therefore, fertilization should be carried out according to the crop's growth condition: in the early stage, mainly nitrogen fertilizer to promote vegetative growth; in the middle and late stages, nitrogen, phosphorus, potassium, trace elements and organic nutrients applied in combination to promote reproductive growth and improve quality and yield.
16. As long as fertilizer is applied, there will be a fertilizer effect
The fertilizer effect of fertilization is related to soil characteristics, crop nutrient absorption characteristics, fertilizer nutrient release characteristics, and many conditions such as water, air and heat. If the influence of various factors is not fully considered, it is very easy to cause nutrient loss, nutrient deficiency and other phenomena.
Sandy soil has a fast fertilizer effect, but loss is also fast, so it should be carried out on the principle of applying less but multiple times. Clay loam has a slow fertilizer effect, so sufficient base fertilizer should be applied and topdressing should be applied early. Potassium fertilizer has good solubility, but loss is also fast, so it should be applied in time according to the crop's potassium requirement characteristics. Organic fertilizer and phosphate fertilizer have slow fertilizer effects and less loss, so they should be applied early. Ammonium bicarbonate is highly volatile, and can be composted with organic fertilizer or phosphate fertilizer for 1-2 days before application, which can reduce nutrient loss.
17. Inaccurate fertilization area
Some fruit growers mistakenly believe that the roots near the trunk are the main part for absorbing fertilizer, so when fertilizing they often apply fertilizer concentrated near the trunk, or even pile it around the trunk, which fails to achieve the fertilization effect. The correct fertilization range is to dig a ring-shaped trench centered on the edge of the tree canopy projection for fertilization.
The depth should be controlled at 20-30 cm for mature fruit trees and 30-40 cm for young trees. If applied too deep, the shallow root system cannot absorb nutrients, and it plays little role in flower bud formation and improving fruit quality, especially for dwarf dense-planted fruit trees with relatively shallow root distribution. This leads to low yield and poor quality. Moreover, deep fertilization wastes labor and effort.
18. Focusing only on the amount of fertilizer applied, not on nutrient content
Some compound fertilizers appearing on the market are widely used in rural areas because of their relatively low unit price. These compound fertilizers generally have the phenomenon of low effective component content, or very low content of one of the three major elements, or none at all. But farmers do not pay enough attention to these situations and still continue the fertilization habit for high-content compound fertilizers. As a result, the nitrogen, phosphorus and potassium applied are insufficient, causing crop nutrient deficiency and nutrient deficiency symptoms, affecting yield and quality.
Therefore, when using these compound fertilizers, one should fully understand the nitrogen, phosphorus and potassium content of these compound fertilizers, and according to the fertilizer requirement characteristics of various crops, use nitrogen, phosphorus, potassium, trace elements, organic nutrients, etc. in combination to ensure normal crop growth and increase yield and income.
19. Neglecting the balance among elements when fertilizing
Fruit tree growth requires the absorption of multiple nutrient elements. In addition to major elements, medium and trace elements and organic activated nutrients are also very important. At the same time, the proportion of various elements in the soil also affects the absorption by fruit trees. Because various elements have promoting or antagonistic effects among them. For example, excessive application of nitrogen fertilizer will inhibit the absorption of potassium, boron, copper, zinc and phosphorus. Too much phosphate fertilizer will inhibit the absorption of potassium and magnesium. However, in actual production, some fruit growers do not pay attention to or do not understand the balancing effect of fertilizers, and when fertilizing they often focus on nitrogen and phosphorus, applying less of other elements, leading to the occurrence of nutrient deficiency symptoms, with low yield and declining quality.
The correct approach is, first, to understand the type of soil, the amount of nutrient elements in the soil, and the demand of fruit trees at different developmental stages for different nutrients. Apply different fertilizers at different periods. Determine the fertilization amount according to yield. Only then can the occurrence of nutrient deficiency symptoms be avoided. To achieve the goal of high yield and high quality. Soil testing and formula fertilization technology can be adopted.
20. As long as major element fertilizer is used, it will definitely be fragrant and sweet
Major elements are the basic elements on which crops depend for growth, but some crops need a relatively large amount of organic activated nutrients during the whole growth period or a certain growth period, and at the same time the soil lacks these nutrients. If not supplemented in time, it will cause melons to be not sweet, fruits to be not fragrant, and product yield and quality to decline sharply, etc.
Natural organic matter degradation products—such as humic acids and marine extracts contain substances such as sugars, amino acids, organic acids, phenols, alkaloids, vitamins, celluloses, hormones, enzymes and their derivatives and intermediates, and aromatic substances. These substances can dissolve in water and be directly absorbed by plants, and are now collectively called organic activated nutrients. They can be directly absorbed and transformed by plants, making fruits fragrant and sweet.
Research at home and abroad shows that: fruits with overflowing fragrance and sweet taste generally have more than 240 volatile components, mainly esters, aldehydes, alcohols, sulfur-containing compounds, ketones and terpenoids. During the fruit expansion period, special attention should be paid to the internal nutrient transformation of the fruit, supplementing organic activated nutrients in time, so that the fruit is sweet and juicy, with rich flavor, striking fragrance, and sweet taste.
21. Excessive use of a certain nutrient element
This will not only poison the crop, but also hinder the crop's absorption of nutrient elements, causing nutrient deficiency symptoms. For example, excessive nitrogen application will cause calcium deficiency; too much nitrate nitrogen will cause molybdenum deficiency; too much potassium will reduce the availability of calcium, magnesium and boron; too much phosphorus will reduce the availability of calcium, zinc and boron.