What are the main factors that affect fertilizer efficiency?
What factors affect fertilizer efficiency? Please explain the following reasons that affect fertilizer use efficiency: 1. Differences in fertilizer varieties. Among straight fertilizers, fertilizers in different forms suit different crops, application times and so on; for example, nitrate nitrogen is suitable for most dryland conditions and works better than ammonium nitrogen in autumn and winter; chloride...
What factors affect fertilizer efficiency? Please explain
The following reasons affect fertilizer use efficiency:
1. Differences in fertilizer varieties. Among straight fertilizers, fertilizers in different forms suit different crops and application times; for example, nitrate nitrogen is suitable for most dryland conditions and works better than ammonium nitrogen in autumn and winter; potassium chloride is suitable for paddy fields and crops valued for fiber, while potassium sulfate works better for crops valued for starch, sugar content and the like; for crops rich in aromatic substances such as tobacco, scallions and garlic, ammonium bicarbonate works better than urea....... Similarly, compound (blended) fertilizers made from different raw materials also differ greatly in their suitable crops and application times.
2. Differences in fertilizer quality. Straight fertilizers from different places of origin and production processes differ in purity and impurity content, so naturally their application effects also differ greatly. For example, in agricultural production, calcium superphosphate often burns seedlings, usually because it contains too much free acid, trichloroacetaldehyde and trichloroacetic acid; some urea has excessive biuret, which causes leaf burn and seedling damage; some of you may know that much potassium dihydrogen phosphate used at the young fruit stage causes scarring on fruit skin, while some potassium dihydrogen phosphate does not, all because of fertilizer quality factors.
3. Differences in commercial fertilizer quality. This includes the fertilizer's appearance, content, weight, composition and so on. For example, powdered fertilizers are more likely than granular fertilizers to damage leaves when used improperly; defects in slow- and controlled-release fertilizer processes cause problems with nutrient release; differences in content and weight cause users' application rates to differ from the plan, and so on. Where the threshold for fertilizer production is low and regulation is inadequate or not in place, some commercial fertilizers also have certain problems in this respect, affecting application results.
4. Choice of fertilizer variety and formula. Different crops and different growth stages have very different nutrient needs. Before use, fertilizers should be selected according to fertilizer properties, crop nutrient requirements and production management models. For example, most crops have relatively high phosphorus requirements at the seedling stage and greater potassium needs later, so phosphate fertilizers and balanced compound fertilizers are more suitable as base fertilizer; water-soluble fertilizers and high-potassium compound fertilizers are suitable for later topdressing; before crops are about to enter reproductive growth, high-nitrogen fertilizers should be stopped and fertilizers higher in phosphorus and potassium should be used, and so on. Some people also do not pay attention to supplementing secondary and trace elements and apply only nitrogen, phosphorus and potassium, which naturally is futile. This is the first step in fertilization. If the fertilizer is chosen wrongly, how can results be achieved?
5. Application timing. Crops, like people eating three meals a day, must have nutrients supplied on time. Many farmers now play the game of "not releasing the hawk until they see the rabbit" - no pesticide until pests and diseases cover the branches, no fertilizer until leaves turn yellow; or else they topdress once every three days and irrigate once every five days when market prices are good; and some apply fertilizer either too early or too late, pursuing a "big and complete" approach and mixing everything in together. Everything has a "limit." Not applying when it should be applied, and applying randomly when it should not be, how can the effect of fertilization be seen? Take calcium fertilizer again: because its absorption and transport are slow, it should be supplemented in good time before the peak demand period, otherwise calcium deficiency symptoms easily appear. Therefore, on the basis of a good base fertilizer, timely and appropriate topdressing according to crop growth needs is what allows fertilizer efficiency to be fully exerted.
This application timing also includes the question of the suitable time of day for fertilization. Temperature and humidity differ in the morning, noon and evening. It is recommended to avoid fertilizing at noon under high temperature, high humidity and strong light, especially when applying foliar fertilizer, as this helps avoid damage to crop roots, tender shoots and leaves.
6. Application method. This means how the fertilizer is supplied to the crop so that the crop can absorb and use it. Common methods in production include: surface broadcasting, application mixed with water, buried application, flushing and flood irrigation, drip irrigation under film and foliar spraying, and so on. The best methods are drip irrigation under film and burying in the soil with cover; broadcasting has the worst effect! Yet most farmers, disliking the trouble, prefer broadcasting. Now some manufacturers' materials introduce their water-soluble fertilizer products as having a use efficiency of nearly 60-80% (how credible?), which should be achieved through drip irrigation, buried application and so on. Think about it: ammonium bicarbonate surface-broadcast may have a use efficiency of only a few percent, sigh! Some manufacturers overemphasize the effect of foliar topdressing, which is also a "wild goose chase." "Uncle Li" long ago said, on a hot day giving you each a wet towel to wipe your face and quench your thirst, does that work? Foliar topdressing is suitable for use during crop growth peaks, when the root system and transport system cannot supply enough nutrients in time, and when appropriately and quickly supplementing secondary and trace elements. Now the method of injecting nutrients into branches and trunks also has a good effect and facilitates nutrient regulation.
7. Application position. This is divided into underground and aboveground parts. At the root crown of the plant there are often thick, sturdy roots with limited absorption capacity; if the application position is too far away, where there are few or no roots, it is not easy to use. For different crops, the application position should be determined according to the root distribution characteristics at different growth stages, so as to facilitate crop absorption. At the same time, the application position in the plant root system should also be determined according to the type of fertilizer applied. For example, fruit trees generally, depending on tree size, use an annular band from 30-50cm outside the trunk to within the canopy drip line as the best application range, and within this annular band one can further determine hole application, strip application, radial trench application and so on, while phosphorus fertilizer is best applied concentrated in the dense root zone within this annular band. If the application position is too close to the plant, it easily causes seedling burn and damage to the trunk. As for application depth, it should be determined according to crop type, with a range of 5-40cm below the surface being best. For supplementing nutrients through the aboveground part, first, the underside of leaves uses them better than the upper surface; healthy leaves use them better than old leaves; second, different nutrients have different effects in different parts of the plant. For example, when supplementing elements that are not easily translocated, old leaves should be the focus of spraying, and this also does not easily cause problems. Now some landscape trees and fruit trees are given fertilizer by soaking or injecting the trunk and thick roots, and the effect is also very good.
8. Application amount. The amount of base fertilizer should be determined according to factors such as soil, crop growth conditions and yield (including roots, stems, leaves, flowers and fruits); when topdressing, the amount should also be determined by considering the base fertilizer situation and the application interval. Blind application of amounts either causes crops to run out of nutrients and senesce early, or causes excessive vegetative growth and waste of fertilizer and labor.
9. Factors in mixed fertilizer application. Regarding the mixed application of fertilizers, one should consider whether mixing will cause volatilization, solidification and other factors. For example, whether the acidity and alkalinity are consistent, whether reactions occur, whether antagonism arises; most of the time calcium fertilizer should be applied separately to avoid affecting the use of calcium and other nutrients; phosphates easily combine with iron, manganese and so on, affecting the use of phosphorus and trace elements; sometimes some fertilizers after mixing produce hygroscopicity, which also affects fertilizer use and utilization.
10. Crop species and variety. Different crops, and different varieties of the same crop, all differ in fertilizer nutrient requirements. Applying fertilizer in a generalized way can neither meet demand nor easily avoid nutrient deficiency problems. For example, legume crops and cucurbit crops differ greatly in nitrogen requirements, as do different growth stages; different varieties of the same crop sometimes differ greatly in vigor, and their nutrient requirements also differ greatly, so fertilization should be based on their characteristics.
11. Crop growth conditions. During crop growth, vigor varies: there are seedling-stage and mid-to-late-stage crops, healthy and excessively vigorous ones, extremely poor or even prematurely senescent ones, and diseased or pest-infested ones. Whether to apply fertilizer should also fully consider crop growth conditions to determine how to fertilize and how much to apply. Special attention should be paid to the crop root growth condition, which is very easily overlooked! Because different growth conditions lead to large differences in nutrient absorption capacity. Sometimes when the root system is poor, applying too much fertilizer instead aggravates root damage, so that the more fertilizer is applied, the less the crop grows, or it even shrinks.
12. Soil conditions. This includes differences in soil texture, such as sandy loam and clay soil differing greatly in water- and fertilizer-holding capacity, causing differences in nutrient capacity in the soil; differences in soil nutrients, such as shale-weathered soil and sandy soil lacking organic matter and some secondary and trace elements, while alluvial plain soil is rich in organic matter and has a strong buffering capacity against high fertilizer concentration; differences in soil pH directly cause obstacles to crop nutrient absorption, such as some soils with high salinity-alkalinity and pH where iron, zinc, molybdenum and so on cannot be absorbed and used, and in production attention should also be paid to chloride ion hazards; and soils with lower pH; the level of pH also affects the simultaneous absorption of ammonium nitrogen and nitrate nitrogen; some soils have been continuously cropped for too long, and excessive accumulation of toxic and harmful substances in the soil affects normal crop growth, so reasonable crop rotation should be carried out together with microbial fertilizers for a better effect; dryland and paddy fields differ even more, and some effects are described under moisture.
13. Moisture factors. This factor includes soil moisture, air humidity, rainfall and so on. Nutrients applied into the soil or on the leaf surface are greatly affected by moisture factors, such as effects on fertilization concentration, fertilizer release speed, changes in fertilizer physical and chemical properties, fertilizer loss and so on. For example: affected by technical and process levels, many controlled-release fertilizers actually have relatively high moisture requirements and are not necessarily as completely unaffected by moisture as manufacturers describe, let alone ordinary compound fertilizers? For another example, under overly dry conditions, boron is not easily absorbed, while under overly waterlogged conditions, iron is not easily absorbed; when fertilizing in the rainy season, defects in the method aggravate fertilizer loss. Therefore moisture is also a factor affecting fertilizer utilization.
14. Temperature factors. On one hand, temperature differences not only affect root absorption of nutrients, but also affect absorption of nutrients supplemented through leaves via the opening and closing of stomata. For example, at low temperatures in spring, crops absorb calcium and magnesium from the roots very poorly, often causing symptoms of calcium and magnesium deficiency in plants; at high temperatures nutrient absorption is better and plants are prone to excessive vegetative growth. On the other hand, temperature changes also greatly affect the physical and chemical properties of fertilizers, with more loss at high temperatures; for example, ammonium bicarbonate volatilizes more at high temperatures. In greenhouses, when the temperature is too high, fertilizer damage often occurs, so attention should be paid to ventilation and cooling to remove excess harmful components.
15. Light factors. This point often does not attract much attention, because strong light is generally accompanied by high temperature, and the cause is all attributed to temperature factors. But in pesticides, this point is emphasized more. Light not only greatly affects the physical and chemical properties of fertilizers, but also has a certain effect on plant nutrient absorption. For example, under strong light conditions, the plant's response to zinc is greatly affected; sometimes white leaves can be seen on ginger, and this also occurs because of problems with ginger's absorption of trace elements such as zinc and iron; tea leaves under strong light also show nutrient absorption problems. When applying foliar fertilizer, strong light affects fertilizer absorption through its effect on leaf stomata. Strong light often accompanies high temperature and causes excessive water loss in plants, even leading to fertilizer damage.
In addition, human and mechanical factors causing uneven fertilizer spreading, air movement causing uneven foliar fertilizer spraying, defects in planting facilities and so on all easily interfere with and affect fertilizer utilization.
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