When sowing corn, the seeding depth should be appropriate and uniform, with a recommended covering depth of 4–5 centimeters. Before germination, the seed needs to absorb about 30% of its own weight in water; stable soil moisture in the seedbed and close contact between the seed and the soil facilitate imbibition and germination. After emergence, secondary roots begin to develop, with the earliest-formed secondary roots typically emerging about 2 centimeters below the soil surface, independent of the seeding depth.

In general, the sowing depth is equal to the length of the hypocotyl—the distance from the secondary roots to the seed—plus 2 centimeters. Throughout its life cycle, maize obtains the vast majority of its water and nutrients through its secondary roots; moreover, a well-developed secondary root system enhances the plant’s resistance to early-stage root lodging and drought stress.

Typically, the soil layer within 5 cm of the surface exhibits relatively stable soil moisture, allowing the soil to better surround and envelop the seeds, which facilitates seed germination; consequently, when the sowing depth is between 4 and 5 cm, secondary root development is optimal. Sowing too shallow, however, can hinder the formation of secondary roots.

During early spring sowing, solar radiation is relatively weak, and direct sunlight has only a limited warming effect on the soil. In addition, the large diurnal temperature range in spring means that although temperatures near the soil surface rise more rapidly during the day, they also drop more sharply at night. By contrast, temperatures at greater depths in the soil exhibit smaller daily fluctuations. Consequently, the overall daily average soil temperature shows no significant difference.

During summer sowing, intense sunlight leads to rapid water loss from the soil surface and low relative soil moisture, which can impair seed imbibition, germination, and secondary root development; therefore, seeds should not be sown too shallowly.

In addition, during sowing it is essential to maintain field capacity at or above 60%; otherwise, irrigation should be applied prior to seeding. When applying fertilizer simultaneously with seed, the distance between the fertilizer and the seed should be 10–15 cm to prevent direct contact that could lead to seed or seedling injury due to fertilizer burn.

III. Seeding Rate and Seeding Density for Silage Corn

The seeding rate is doubled compared with that used in commercial fields, typically 6–8 kg per mu. Proper planting density is conducive to high yields; a row spacing of 35 cm or 45 cm is generally adopted, with a stand density of 5,000–6,000 plants per mu.

Hebei Muzhe Agricultural and Pastoral Machinery Co., Ltd. is a subsidiary of the Nonghaha Group and currently primarily manufactures Self-Propelled Silage Harvester 4QZ-18A This silage harvester features a compact design and high operational efficiency, with kernel-crushing performance comparable to that of the world’s most advanced forage-harvesting machines. The company boasts state-of-the-art processing equipment and a comprehensive suite of inspection and testing instruments. We have acquired advanced machinery such as single-screw air compressors, CNC lathes, CNC plasma cutting machines, large-scale laser cutting machines, and dynamic balancing testers, establishing a fully integrated production and machining system that lays a solid foundation for manufacturing high-quality products that have earned widespread acclaim. Customers from all regions are welcome to visit us for on-site inspections. Contact number: 0311-87513873   。