After selecting good varieties and seeds, proper sowing can yield higher yields and benefits. In a given climate and production conditions, there is only one optimum sowing date or optimal sowing time for a particular variety, but due to climate and technical reasons, the best sowing date cannot be determined precisely before birth.
Factors affecting the sowing date
temperature. In China's spring corn producing areas, temperature is an important factor affecting the sowing date. Generally speaking, when the soil temperature is lower than 8°C, the seeds germinate slowly, the seedlings are weak, and the emergence is not neat. The pests and diseases are more serious. When the seed bed temperature has reached 8°C-12°C for at least 5 days to 10 days, it can be sown.
Moisture and ventilation. Drought can cause germination and seedling to appear irregular, and when it is severe, shoots are destroyed. If the soil moisture content is too high, the soil will have poor ventilation and the soil temperature will rebound slowly, which is also not conducive to emergence. The ideal soil moisture content for sowing is 70%~75%. In years and areas where the soil moisture is poor and the drought time is longer during sowing, irrigation or sitting water is needed. In addition, the sowing date can be adjusted so that corn can avoid seasonal drought during the key period of growth and development, such as 15 days before tasselling and 15 days after tasselling.
Growth Period. The medium-early-maturing varieties have a longer suitable sowing time, and the sowing time can be selected according to the climate, soil and comprehensive production situation.
Light temperature characteristics. Varieties with poor photo-sensitivity, such as Zhongdan 9409, were planted in the south and north. Little change in the growth period. Light-temperature-sensitive varieties such as Dandan 13 have significant changes in planting and fertility in different regions.
Sowing date should be adjusted properly
Adjust the sowing date appropriately. Can reduce the harm of pests and diseases. For example, in the Jinzhong region and the Northeast Plain, adjusting the sowing date can greatly reduce the incidence of corn virus disease and smut.
In two or more mature areas, the arrangement of cornices should also be considered during the sowing period in order to increase the efficiency of land comprehensive utilization and annual production yield. Such as wheat - corn two ripe areas, the sowing date of summer corn should be arranged according to the harvest period of wheat, after wheat harvest, it is necessary to timely rob, build hoe, rush early sowing. Summer maize often has the habit of waiting for rain sowing. If you use a late-maturing variety or mature Chuanchuanchuan, do not wait for rain sowing. In the southern area of ​​Huanghuai, if soil moisture after wheat harvest is poor, in order to reduce production costs and increase planting efficiency, early-maturing varieties or medium-early-maturing varieties can be properly sowed, but the time must be controlled to ensure that the corn can mature normally. For example, in the southern area of ​​the east and west mountains, the sowing date of winter wheat is from October 1st to October 10th. Therefore, corn should be mature before October 1st. If it is a 90-day variety, it is better to sow before June 30th. .
During the appropriate sowing period, early spring sowing of spring corn can obtain higher yield and quality. However, studies have also shown that premature sowing, low temperatures, corn seedlings are slow, pests and diseases increase, and when the temperature is appropriate from late May to early June, due to thin and thin seedlings, growth is relatively slow, but can not effectively use the temperature. However, when the seeds are sown late and seedlings are seeded quickly, the seedlings are strong, but they can better use the rising temperature. If the optimum seeding period has passed, when sowing, reseeding or replanting - select the medium-early-maturing or early-maturing varieties.