Before the corn is planted, the soil is tested, and then the formula fertilization is carried out. The organic fertilizer is mainly applied, generally 40,000 kg/hm2, and the phosphate fertilizer is 850-1 lkgkg/hm2, and the potassium sulfate is 320-368 kg/hm2, so that the soil can be comprehensively improved. Physical properties, at the same time, its long-term fertilizer effect, soft texture, comprehensive nutrients, which plays an important role in cultivating strong seedlings and capturing high yields. At the same time, it is necessary to use the fertilizer reasonably, generally using 60kg/hm2 of three-element compound fertilizer.
2 skillfully applied fertilizer
The growth of corn seed production is relatively slow. Generally, the jointing begins about 10 days, and from the external form, the leaves are generally 6 to 9 pieces, and the leaves are 9 to 12 pieces. At this time, the corn seed production enters the jointing stage, which is also the corn chase. The best time to apply fertilizer. When the corn enters the jointing stage, the stems and leaves grow vigorously, the tassels begin to differentiate, and the nutrient requirements are increasing. The timely topdressing can promote the roots and strong stalks, and lay the foundation for high yield. In this period, the topdressing amount accounts for 35%-40% of the total topdressing amount. Preferably, the urea is generally 155 to 178 kg/hm2.
3 re-application of the panicle fertilizer
When the corn enters the big mouth, the top dressing is called the boot fertilizer. Corn enters the booting stage, which is the fastest period for absorbing nutrients. It is the peak period of floret differentiation of maize ears. It is the peak period of corn fertilizer. At this time, the application of the ear fertilizer can not only meet the needs of rapid growth and development of corn, but also promote the plant. The middle and upper leaves are enlarged, the light-receiving conditions are improved, the photosynthesis ability is increased, the functional time of the leaves is prolonged, and the chlorophyll content of the leaves is increased, and the photosynthetic efficiency is improved to ensure sufficient nutrients are transferred to the ears in the later stage, so that the weight of the seeds is increased. The increase in the content of photosynthetic products increases the fullness of the seeds and increases the 1000-grain weight, which can significantly increase the yield per unit area of ​​corn. Tests have shown that timely application of booting fertilizer can generally increase corn production by 10%-20%. At the same time, the test proved that the amount of topdressing in this period accounted for 50%-55% of the total topdressing amount, generally 225-242kg/hm2 of urea.
4 Discretionary fertilizer
The top dressing of the corn before the flowering of the loose powder is called the attacking fertilizer. After the corn is flowering and loosening, it enters the reproductive period centered on reproductive growth. Although there is not much fertilizer in this period, it is essential to topdress in time, and it is necessary to grout, enrich the grain, increase the grain weight, reduce the baldness and increase the individual ear. The yield has a significant promotion effect. At this time, the top dressing accounts for 10%-15% of the total topdressing, generally 65~95kg/hm2 of urea, and the yield can be increased by 7.5%-12%.
In the implementation of jointing fertilizer and booting fertilizer, the parents should be fertilized in stages according to the parents' growth status, and the male parent does not need to apply the panicle fertilizer.
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