What is the most suitable wheat seeding rate per mu? Including the seeding rate calculation formula
Autumn is the harvest season, and in the blink of an eye it is almost time to plant wheat. In northern regions, the wheat sowing period is generally after Cold Dew and before Frost's Descent. Many farmer friends are unsure about the most suitable wheat seeding rate, so today we will explain it in detail.
What row spacing for wheat sowing helps achieve high yields
At present, wheat sowing is generally done with a seeder. Machine sowing gives straight and even rows, uniform seed placement, and consistent sowing depth, which helps the wheat seedlings emerge evenly, completely, and strongly. It is best to plant in equal rows spaced 15-16 cm apart, which can increase ground cover, reduce surface moisture evaporation, and has the effect of saving water and increasing yield.
To make wheat field management easier, leave a 20 cm wide row between each sowing strip, and a sowing depth of 3-4 cm is appropriate. This allows wheat to overwinter safely. Practice “loose soil” moisture conservation; do not press soil immediately after sowing. Wait 1-2 days after sowing until there is a 0.5-1 kg dry soil layer on the surface before pressing, which helps conserve moisture.
What wheat seeding rate is most suitable
Many farmers always increase the seeding rate to prevent uneven wheat emergence, and some even double it. Plant protection experts advise everyone to control the seeding rate well. If the seeding rate is too large, there will be too many seedlings per unit area, individual plants will compete strongly with each other, resulting in weak seedlings and making lodging very likely, thereby reducing yield.
Generally, under timely sowing conditions, for large-spike varieties with a low tillering-to-spike rate, the suitable basic seedling number per mu is 150,000-180,000; for medium-spike varieties with a high tillering-to-spike rate, the suitable basic seedling number per mu is 120,000-150,000. Within this range, high-yield fields should have fewer, and medium-yield fields should have more. If sowing later than the suitable sowing period, for every 2 days delayed, increase the basic seedling number per mu by 10,000-20,000. For dryland wheat fields, the basic seedling number per mu is 120,000-160,000, and for late-stubble wheat fields, the basic seedling number per mu is 200,000-300,000.
Within the suitable sowing period, for ordinary plots, the seeding rate per mu for semi-winter varieties is 7-9 kg, and for weak spring varieties it is 9-11 kg. For dryland, the suitable seeding rate per mu is 7.5-10 kg; for irrigated land, the suitable seeding rate per mu is: drilling 12.5-15 kg, broadcasting 15-17.5 kg. For each day earlier or later outside the suitable sowing period, decrease or increase the seeding rate per mu by 0.5 kg.
If sowing is delayed, the seeding rate should be appropriately increased. Generally, for each day of delay, increase the seeding rate by 0.25-0.5 kg. When sowing, use a seeder, require precise seeding rate, uniform seed placement, and consistent depth to ensure sowing quality.
How to determine the wheat seeding rate
Determine the seeding rate according to factors such as the planned basic seedling number, seed germination rate, field emergence rate, and 1000-grain weight. Generally speaking, under timely sowing, suitable soil moisture, and normal seed germination rate, the seeding rate can be determined according to the principle of “one jin of seed for ten thousand seedlings.”
From the perspective of economic cultivation with the best benefits, the optimal plan, and the smallest risk, within the suitable sowing period, semi-precision sowing with about 160,000 basic seedlings per mu is the easiest way to obtain high yields over a large area, that is, about 8 kg of seed per mu.
For example, in the Weifang area of Shandong, sowing from October 5-10, about 8 kg of seed per mu is more suitable; sowing on October 15, about 10 kg of seed per mu is more suitable.
Wheat seeding rate calculation formula
To calculate the wheat seeding rate, first determine the target yield according to soil fertility and water and fertilizer conditions, determine the number of spikes per mu from the target yield, then determine the suitable basic seedling number from the number of spikes per mu, and then calculate the suitable seeding rate according to the basic seedling number, the variety's 1000-grain weight and germination rate, and the field emergence rate.
In production, the experience of “500 grams of seed for ten thousand seedlings” is commonly used. However, this varies due to differences in variety, seed, and land preparation quality, so the seeding rate per mu should be calculated according to the following formula:
Seeding rate per mu (kg) = planned seedling number per mu × 1000-grain weight (g) ÷ (1000 × 1000 × germination rate × field emergence rate)
Finally, a special reminder to farmers: do a good job of pressing the soil after sowing.
If pressing is not done, especially in plots using straw return and rotary tiller cultivation, because the plow layer soil is loose, it is easy to cause wheat to be sown too deep, forming deep-sown weak seedlings, affecting the occurrence of wheat tillering, causing insufficient spike number and reducing yield.
After wheat sowing, press twice with a roller to ensure normal root growth after wheat emergence and improve drought resistance and cold resistance.
Precautions
Because the seeding rate is too large and there are many basic seedlings, wheat is prone to lodging in the later stage, especially after heavy application of jointing and booting fertilizer, making it very easy to lodge. This makes it difficult to apply the most important topdressing in wheat production, limiting the improvement of wheat yield. In production, the seeding rate should not be blindly expanded, and should be reasonably determined according to the sowing period and other conditions.