Detailed Explanation of Key Corn Planting Techniques and Management Methods
Corn, China's largest grain crop. In biological terms, corn is a C4 plant, yet its husk leaves use the C3 mode for photosynthesis. It is monoecious, and its main producing area lies in the world's third-largest corn belt——the Songliao Plain corn belt of China. The total corn planting area is about 1,249.35 sq km. It is also known as maize, baogu (baogu bang), baomi, and bangzi. In Cantonese it is called sumi, and in Minnan dialect it is called fanmai. It is an annual herbaceous plant of the grass family, an important food crop and an important feed source, and also the grain crop with the highest total output in the world.
Selection of Corn Varieties
Knowing how to select good corn seed varieties is a key issue related to increasing autumn yields. When selecting good corn varieties, the following principles should be followed:
1. Select varieties according to heat resource conditions: The local heat resources are related to the growth period of the corn variety. Corn varieties with a long growth period have good yield performance and high yield-increasing potential, and the local heat and growth period must meet the needs for the variety to fully mature. If heat is sufficient, try to choose corn varieties with a longer growth period, so that the production potential of excellent varieties can be effectively brought into play. However, if one pursues high yield too much and adopts corn varieties with an excessively long growth period, the corn will not fully mature, the kernels will not be plump enough, and the nutrition and quality of the corn will be affected. Therefore, when choosing corn varieties, it is necessary both to ensure that the corn matures normally and not to affect the timely sowing of the next crop. The terrain height is related to ground temperature: highland areas have higher temperatures, so late-maturing varieties or mid-late-maturing varieties with a long growth period are suitable; for flat land, mid-late-maturing varieties are suitable for the growth period; for low-lying land, mid-early-maturing varieties are suitable.
2. Select varieties according to local production and management conditions: The yield potential of corn varieties is related to production and management conditions. Varieties with high yield potential require good production and management conditions, while varieties with lower production potential require relatively lower production and management conditions. Therefore, in areas with a relatively high level of production management and fertile soil and sufficient water sources, corn varieties with high yield potential and high yield-increasing potential can be selected. Conversely, varieties with slightly lower production potential but better stability should be selected.
3. Select varieties according to the previous crop: The yield and income increase of corn varieties are directly related to the previous crop. If the previous crop was soybean, the soil fertility is relatively good, and high-yield varieties should be selected; if the previous crop was corn and it grew well and yielded well, the same variety can continue to be selected; if the previous corn crop was infected with a certain disease, varieties susceptible to that disease should be avoided when selecting seed. In addition, the same variety cannot be continuously planted in the same field for three or four years, otherwise soil impoverishment and variety degeneration will occur.
4. Select varieties according to diseases: Disease is the nemesis of high corn yields and is mainly related to the soil. If soil nutrients are unbalanced and ground temperature is abnormal, varieties unsuitable for growth under such conditions should be avoided when selecting seed. For example, “Denghai 9” is only suitable for growing in plots with balanced soil nutrients and a high degree of maturation.
5. Select varieties according to seed appearance: The level of purity and the quality of corn varieties directly affect the level of corn yield. For every 1% decrease in the purity of grade 1 corn seed (98% purity), its yield will decrease by 0.61%. Selecting high-quality varieties is a favorable guarantee for achieving high corn yields. High-quality seed packaging bags are sealed in one step and have the seed company's name and detailed address and telephone number; the seed label clearly states the production date, purity, cleanliness, moisture, and germination rate; the shape, size, and color of the seeds are neat and uniform.
6. Select varieties according to local precipitation and accumulated temperature: According to experience, if the previous winter had little snowfall and the winter was not cold, the following summer will have relatively more rainfall and the accumulated temperature will not be high; varieties with an excessively long growth period will not receive enough accumulated temperature, which affects maturity. Conversely, if the previous winter had heavy snowfall and the winter was very cold, the following summer will generally have relatively less rainfall and the accumulated temperature will be relatively high, making it easy to choose varieties with strong drought resistance, and low-lying land can appropriately plant some mid-late-maturing varieties.
Early Sowing to Catch the Three "Before"s, Drought-Resistant Precision Sowing
Drought-resistant precision sowing to ensure full stands is the prerequisite for achieving high yields. The early sowing to catch the three "before"s technique means sowing early by timely seizing soil moisture, ahead of the spring drought (making full use of the returning moisture); topdressing early before the summer drought (aligning the period of high corn demand for fertilizer and water with the peak of the July and August rainy and hot period); and maturing before frost (making full use of effective accumulated temperature to promote early maturity and increased yield of corn).
1. Early sowing time: between April 15 and 25, with the best time being the 20th. The ground temperature indicator is that sowing can begin when the 10 cm soil ground temperature is stable between 7 and 8°C.
2. Drought-resistant seed treatment: use corn biological seed soaking agent and drought-resistant water-retaining agent for treatment (refer to the variety instructions for usage).
3. Sowing quality: ensure suitable depth, uniform soil covering, and improved seedling emergence uniformity, so as to achieve full stands, uniform stands, and strong seedlings. As yield increases, the effect of sowing techniques on yield gradually strengthens. Sowing techniques include selecting seed treatment, soil moisture preparation, reasonable density, sowing method, sowing rate, and sowing depth.