Best Time and Techniques for Fertilizing Corn Explained in Detail

Corn is one of the main grain crops in our country and is grown fairly widely, with larger planting areas in the northern regions. In the process of growing corn, fertilization is indispensable if you want to obtain high yields. So what are the best time and techniques for fertilizing corn?

1. Best time for fertilizing corn

Throughout the entire growth period of corn, there are three peak periods of nutrient uptake, namely the jointing stage, the booting stage, and the flowering stage. These are what are usually called the three topdressing methods of promoting stalks, promoting ears, and promoting grains, which play an important role in achieving high corn yields.

Stalk-promoting fertilizer. Generally, topdressing is done at the 6-8 leaf stage, when the seedlings are 30 cm tall. Stalk-promoting fertilizer can promote the enlargement of the upper leaves of corn, expand the area of photosynthesis, prolong the functional period of the lower leaves, and lay a good foundation for promoting roots, strengthening stalks, and increasing ears.

Ear-promoting fertilizer. Topdressing is done at the large trumpet stage of corn, that is, 10-15 days before the early tasseling stage, at the 12-13 leaf stage. This stage is the period of most vigorous growth and development of corn, with high demand for fertilizer and water, and it is the key period that determines ear size and the number of grains per ear. At this time, applying heavy ear fertilizer and attacking with both fertilizer and water can not only meet the fertilizer and water needs of ear differentiation, but also improve the photosynthetic productivity of the middle and upper leaves, so that more nutrients are transported to the ear, making the grains numerous and plump, with a significant effect on increasing yield.

Grain-promoting fertilizer. This refers to a topdressing applied around the time the silks of the female ear begin to emerge, before and after pollination. It is mainly to prevent fertilizer deficiency in the later stage, prolong the functional period of the upper leaves, promote grain filling, increase grain weight, and raise yield.

2. Techniques for fertilizing corn

1. Key points of base fertilizer

Base fertilizer can build up soil fertility, improve soil structure, and continuously supply nutrients throughout the entire growth period of corn to ensure normal growth and development. Base fertilizer should be mainly organic fertilizer, with chemical fertilizer as a supplement. Spring corn, as well as summer and autumn corn that can be cultivated before sowing, should all be given base fertilizer as much as possible. For base fertilizer, generally 1500—3000 kg of farmyard manure and stable manure can be applied per mu.

The application method of base fertilizer should be handled flexibly according to the amount, type, and sowing time. If the amount is not large, ridges should be made first, and then furrows should be opened in the middle of the ridges for band application. When the amount of base fertilizer is relatively large, the fertilizer can be evenly scattered on the ground before plowing and turned into the soil together with plowing. Chemical fertilizers such as potassium fertilizer, phosphorus fertilizer, and zinc fertilizer are best applied mixed with organic fertilizer.

2. Key points of seed fertilizer

For summer corn, intercropped corn, and winter-sown corn in soils with poor nutrient content, little base fertilizer, or no base fertilizer, seed fertilizer is even more necessary. Seed fertilizer should be mainly quick-acting nitrogen, phosphorus, and potassium fertilizers and high-quality decomposed human excrement and livestock and poultry manure, but the application amount should not be too much. Generally, 5—7.5 kg of ammonium sulfate, ammonium nitrate, or ammonium chloride can be applied per mu; the biuret in urea easily burns seeds, so the amount should be smaller, and it must not exceed 4 kg per mu at most. When potassium chloride is used as seed fertilizer, the amount per mu should not exceed 7.5 kg at most.

Nitrogen, phosphorus, and potassium compound fertilizer or diammonium phosphate are best used as seed fertilizer, and 10-15 kg can be used per mu. When applying seed fertilizer, it can be applied by opening furrows or making holes and broadcasting, and stirred with the soil before sowing. Seeds and fertilizer must be kept separate to avoid burning the seeds. This is especially important when urea and potassium chloride are used as seed fertilizer.