Because corn has a short growth cycle, fertilizing it is essential for high yields. However, many farmers don't know how to fertilize corn, resulting in fertilizer damage. So, what fertilizer should be used for corn cultivation? How should corn be fertilized? Today, we'll explain corn fertilization methods and precautions.
What nutrients does corn need?
Corn plants contain 16 elements, all of which, except for C, must be absorbed from the soil. Nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium are required in larger quantities, while iron, manganese, zinc, copper, and barium are required in smaller quantities. From 10 days before tasseling to 25-30 days after budding, corn accumulates dry matter rapidly and absorbs the most nutrients. During this period, 70-75% of nitrogen, 60-70% of phosphorus, and 65% of potassium are absorbed. According to calculations, producing 100 kilograms of corn kernels requires 2.5 kilograms of nitrogen, 1 kilogram of phosphorus, and 2.1 kilograms of potassium. For a yield of 500 kilograms per mu (acre), approximately 33 kilograms of urea, or 50 kilograms of ammonium nitrate, 31 kilograms of superphosphate, and 13 kilograms of potassium sulfate are required.
What fertilizer is best for corn?
Throughout its growth cycle, corn requires nitrogen, followed by potassium, and phosphorus. It also requires an appropriate amount of minerals. A nitrogen-phosphorus-potassium ratio of approximately 1:0.49:0.9 results in optimal growth and high yields. A base fertilizer of 3,000 kilograms of organic fertilizer, consisting entirely of phosphorus and potassium fertilizers and 1/3 nitrogen, is recommended. Since corn seedlings have underdeveloped root systems and limited nutrient absorption, a nutrient-rich fertilizer should be used as seed fertilizer. You can also apply well-rotted farmyard manure as well. Generally, apply approximately 6 kilograms of ammonium sulfate or 500 kilograms of well-rotted farmyard manure per mu (acre), with appropriate amounts of phosphorus and potassium fertilizers added as needed. Corn requires the most fertilizer during the tasseling stage, and its absorption rate is also faster. It's best to use fertilizers high in nitrogen.
How should corn seed fertilizer be used?
1. Seed dressing: You can use humic acid, biofertilizer, or micronutrient fertilizer. Dissolve the fertilizer and spray it on the corn seeds, mixing it while spraying to evenly coat the surface of the seeds. Allow the fertilizer solution to dry in the shade before sowing.
2. Seed soaking: Dissolve the fertilizer to a desired concentration and soak the seeds in the solution for 12 hours. Allow the seeds to dry in the shade before sowing.
3. Row or hole application: Chemical fertilizers are suitable for row or hole application, using 2 to 5 kg. However, the fertilizer must be separated from the seeds. Deep application, preferably to a depth of 10 to 15 cm, is recommended. Urea, ammonium bicarbonate, ammonium chloride, and potassium chloride are not suitable for seed fertilizer.
Fertilization methods for corn:
The amount of fertilizer required varies across the three growth stages of corn: 2% during the seedling stage, 85% during the ear stage, and 13% during the grain stage. Corn's fertilizer requirement peaks from jointing to full-blown. When applying fertilizer, consider the appropriate fertilization strategy, combining base fertilizer, seed fertilizer, and topdressing; combining nitrogen fertilizer, phosphorus fertilizer, and potassium fertilizer; and combining agricultural fertilizer, chemical fertilizer, and biofertilizer. Sufficient base fertilizer is essential; generally, 2,000 kg of well-rotted organic fertilizer, 7.5 kg of phosphorus pentoxide, and 5.5 kg of potassium fertilizer per mu (approximately 1000 kg) are applied as base fertilizer.
For plots with low base and seed fertilizer application rates, poor soil conditions, and late-maturing varieties, topdressing can be performed when the corn is 6-7 leaves deep. Apply approximately 15 kg of urea per mu (approximately 15 kg per mu) to a depth of at least 15 cm to improve fertilizer utilization. For plots with high base and seed fertilizer application rates, apply approximately 10 kg of urea per mu (approximately 10 kg per mu). Topdressing corn should be done early. First, apply topdressing first and then tilling the soil later, combining topdressing and tilling. Second, use a pickaxe to dig holes at least 15 centimeters deep. When applying topdressing, combine chemical fertilizers with biofertilizers to promote healthy root development. Generally, applying 10-15 kg of urea per mu and 1 kg of biofertilizer per mu can help the corn mature earlier.
During the heading and grain filling stages, apply 0.25 kg of potassium dihydrogen phosphate and 0.5 kg of urea, diluted with 50 kg of water, to the leaves. This can prevent bald tips and missing grains, increase yield, and improve quality. For organic corn, avoid using chemical fertilizers. Use fermented organic fertilizer as a base fertilizer, and cake fertilizer as a topdressing. This has a more stable and effective effect than chemical fertilizers and has a longer-lasting effect. However, when applying topdressing, keep the cake fertilizer away from the seedlings to prevent the heat from fermenting from burning the seedlings.
Precautions for topdressing corn:
1. Time topdressing appropriately. If topdressing is applied three times, it should not be applied too early during the seedling stage. Topdressing is best done when the seedlings have 5-6 leaves, which helps them grow thicker and stronger. Jointing fertilizer is generally best applied when the seedlings have 10-11 leaves. Mechanical operations can be applied earlier to avoid damage to the seedlings. Pay attention to the amount of nitrogen used for ear fertilizer to prevent premature fertilization. If topdressing is applied once, topdressing should be done at the jointing stage.
2. Apply fertilizer deeply. Topdressing corn must be applied deeply, otherwise it will reduce fertilizer utilization. The ideal depth is 5-10 cm, and cover with soil promptly.
3. Topdress according to growth. In plots with uneven seedlings, treat strong and weak seedlings differently during topdressing. Weak seedlings should be topdressed earlier, and if necessary, foliar fertilizer can be applied separately to promote early and rapid growth. Topdressing strong seedlings should be applied later.
4. Apply potassium fertilizer appropriately. If the potassium content in the base fertilizer is insufficient, apply an appropriate amount of potassium fertilizer to compensate.
5. Apply foliar fertilizer appropriately. Strictly follow the product instructions for spraying frequency, spraying time, and solution concentration. Spraying should be done before 10:00 AM or after 3:00 PM. Spraying can also be done on cloudy days, avoiding direct sunlight. Spray evenly on the underside of the leaves, ensuring no dripping. If heavy rain occurs within three hours of spraying, re-spray. Foliar fertilizer should be sprayed without mixing it with pesticides.
Fertilizing corn depends on soil fertility and weather. Before applying, conduct a soil test to determine the soil fertility level, and then determine the frequency and amount of fertilizer to be applied.
