In the 7th leaf stage of maize, it is the optimum period for the application of jointing fertilizer. It is a time when the maize leaves develop in large numbers, the stems are rapidly elongated, the stems and leaves grow vigorously, and the tassels begin to differentiate, and the need for nutrients is increasing. Urgently, timely application of joint fertilizer, can build a skeleton for high-yield in the later period. So how much fertilizer is applied per acre? Experiments show that soil fertility is low, basal fertility is small, population is small, growth of seedlings is thin, the yield per hectare is 250-300 kilograms, and the amount of top dressing is 45%-50% of the total topdressing amount; moderately fertile plots, soil Good fertility, strong growth of seedlings, high uniformity of field population, dark green leaves, and yields of 550 to 650 kilograms. To avoid seedling growth and ensure robust plant growth, jointing fertilizer can be controlled at 30% of the total fertilizer application. -35% is good; the remaining fertilizer is reserved for tapping applications to meet the needs of rapid increase in trophozoites and continuous differentiation of male and female spikes. Soil fertility, base fertilizer, large populations, robust seedling growth, and high-yield plots with 650-750 kg of yield per mu, in order to prevent overgrowth of nutrients, ensure stable growth of seedlings, and maintain the energy conversion and material metabolic balance of their plants, Easing the competition between groups and individuals on the living conditions, the top dressing should not be too much during this period. The jointing fertilizer generally accounts for 20% to 25% of the total topdressing fertilizer; the remaining fertilizer is reserved for attacking and attacking grain, which is conducive to promoting the spike Increase grain weight and increase production.