When should corn be top-dressed, and what fertilizer works best?
The growth of any crop cannot do without fertilizer, and corn fertilization is no exception. So when is the best time to fertilize corn for good results? The best time to fertilize corn? Next, we will answer these questions for you.
The best time to fertilize corn:
Stem-promoting fertilizer. Generally, top-dress at the 6-8 leaf stage, when the seedlings are 30 cm tall. Stem-promoting fertilizer can promote the enlargement of the upper leaves of corn, expand the area of photosynthesis, extend the functional period of the lower leaves, and lay a good foundation for promoting roots, strengthening stalks, and increasing ears.
Ear-promoting fertilizer. Top-dress at the large trumpet stage of corn, that is, 10-15 days before tasseling, at the 12-13 leaf stage. This stage is the period of most vigorous growth and development of corn, with high fertilizer and water demand, and it is the key period that determines ear size and the number of kernels per ear. Applying a heavy ear fertilizer at this time, with fertilizer and water applied together, 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, resulting in more and plump kernels, with a significant effect on increasing yield.
Grain-promoting fertilizer. This refers to a top-dressing applied when the silks of the female ear begin to emerge, around pollination. It is mainly to prevent fertilizer deficiency in the later stage, extend the functional period of the upper leaves, promote grain filling, increase kernel weight, and raise yield.
Corn top-dressing should be applied in appropriate amounts according to soil fertility, the fertilizer requirements of the variety, and the growth period of the variety, so as to meet the needs of corn growth and development. In some cases, it can be applied once at the large trumpet stage as an ear-promoting fertilizer, or applied twice at the jointing stage and the large trumpet stage. However, the first application should be smaller and the second larger. Whether to apply grain-promoting fertilizer depends on the soil fertility conditions. For soil that is prone to fertilizer deficiency in the later stage, a small amount of grain-promoting fertilizer can be applied, so as to avoid excessive top-dressing causing delayed maturity due to excessive vegetative growth and thus reducing yield.
Related questions and answers
1. Top-dressing too late. Generally, top-dressing is delayed until after tasseling.
2. One-shot top-dressing. That is, no matter what fertilizer it is, all are mixed together and applied as seed fertilizer.
3. Top-dressing based on the weather. If it does not rain, no top-dressing is done, rather than deciding based on the growth conditions of the corn.
I believe many friends have done the above 3 things. In fact, corn top-dressing still has a great impact on later yield. At present, in spring corn planting areas, corn is about to enter or is in the top-dressing period. Little Helper will explain to everyone the specific problems encountered in production:
Q: What is the fertilizer requirement pattern of corn?
A: The seedling stage of corn is the key period for phosphorus and potassium fertilizer requirements, and the large trumpet stage before tasseling is the key period for nitrogen fertilizer requirements.
Q: When is the best period for corn top-dressing?
A: The large trumpet stage is the best period for top-dressing.
Q: What fertilizer is better to top-dress with?
A: Either high nitrogen, low phosphorus, medium potassium or high nitrogen, low phosphorus, low potassium is fine. In actual production, urea mixed with some potassium fertilizer and phosphorus fertilizer is enough.
Q: How many times should it be top-dressed?
A: Under normal circumstances, once is enough. If a plot is particularly deficient in nutrients, it can be top-dressed multiple times according to the specific situation.
Q: How can the top-dressing utilization rate be high?
A: If the planting area is small, manual hole digging and deep application can be used, directly acting on the corn roots, then covering with soil. If the planting area is relatively large, ridges can be opened for top-dressing, scattering the fertilizer into the furrows and then covering with soil. Note here that it must never be directly scattered on the ground surface, causing serious waste.
Q: How much is better to top-dress per mu?
A: Top-dress in appropriate amounts according to soil fertility, the fertilizer requirements of the variety, and the growth period of the variety. Taking urea as an example:
For high-fertility plots, the urea rate is 15-17 kg/mu;
For medium-fertility plots, the urea rate is 18-20 kg/mu;
For low-fertility plots, the urea rate is 21-23 kg/mu.
Regarding the issue of corn top-dressing, Little Helper reminds you of one more point: when the soil is dry, top-dressing is not recommended, and it is best to top-dress before rain. At the same time, for plots prone to delayed maturity due to excessive vegetative growth, increase the application of phosphorus and potassium fertilizers to promote the corn maturing as soon as possible.