Why Spring Corn Fertilization Should Be Light Early and Heavy Late
The corn borer, also known as the corn stalk borer. Spring corn is currently at the late whorl stage (funnel stage), and this period is the best time to control the corn borer. At the funnel stage, most newly hatched corn borer larvae crawl into the leaf whorl tube and feed on the mesophyll of the not yet unfolded leaves, and spraying at this stage makes it easy for the spray liquid to enter the leaf whorl tube, improving control effect...
Base fertilizer: Spring corn should be fertilized according to the basic principles of mainly base fertilizer with supplementary topdressing; mainly farmyard manure with supplementary chemical fertilizer; mainly nitrogen fertilizer with supplementary phosphorus fertilizer; mainly ear fertilizer with supplementary grain fertilizer.Base fertilizer should generally account for about 70% of the total fertilization amount, and most phosphorus fertilizer should also be applied together with the base fertilizer, generally applied in combination with autumn plowing in the previous year. When applying base fertilizer, it should be evenly mixed with the soil, and generally 37.5-60 tons of farmyard manure per hectare should be applied as base fertilizer. If nitrogen fertilizer is used as base fertilizer, 375 kg of ammonium bicarbonate or 150 kg of urea can be applied per hectare. It must be applied deeply to prevent nitrogen volatilization loss. In phosphorus-deficient soil, apply 450-600 kg of superphosphate per hectare; in potassium-deficient soil, apply 150 kg of potassium chloride per hectare; in zinc-deficient soil, apply 15 kg of zinc sulfate heptahydrate per hectare.
Seed fertilizer: Before spring sowing, apply a small amount of farmyard manure together with an appropriate amount of nitrogen and phosphorus chemical fertilizers in furrows or holes as corn seed fertilizer.
Topdressing: Corn topdressing is an important measure for high-yield corn cultivation. Because spring corn has a longer growth period and slow seedling growth with less nutrient absorption, spring corn topdressing mostly adopts the "light early, heavy late" fertilization method, that is, applying 1/3 of the topdressing before corn jointing, with 75-150 kg of urea per hectare, and applying 2/3 of the topdressing at the large funnel stage, with 150-300 kg of urea per hectare, to meet the nutrient needs of corn earlet and floret differentiation as well as the grain formation stage. Experimental results confirm that spring corn using the "light early, heavy late" fertilization method increases yield by 13.3% compared with the "heavy early, light late" fertilization method.