Latest measures for overwintering rapeseed seedling protection, helping seedlings survive winter safely

Rapeseed is an autumn-sown, winter-grown crop. It has some ability to withstand severe cold, but cold air invasions and improper sowing and fertilizing often cause frost damage to rapeseed, resulting in varying degrees of yield reduction. Therefore, when rapeseed overwinters, you should take corresponding mature techniques according to local actual conditions to prevent or reduce frost damage to rapeseed and help it overwinter safely.

1. Apply more fertilizer

Phosphate fertilizer can promote the growth and development of the rapeseed root system and enhance resistance, while potassium fertilizer can improve rapeseed's cold resistance, disease resistance and lodging resistance. Therefore, in winter you can apply some phosphorus and potassium fertilizer to rapeseed. This can not only promote the growth of rapeseed, but also increase its frost resistance. Before overwintering, you can also use organic fertilizers such as pig and cattle manure and soil-surface ash, and at the same time combine it with hilling soil around the roots, which can also increase the frost resistance of rapeseed. The amount of fertilizer applied should also be controlled well, and it should not be applied too much. Generally, 2000-3000 kg of farmyard manure per mu, together with 10-15 kg of calcium phosphate and 50-10 kg of potassium chloride, is sufficient.

2. Intertillage and hilling

During the overwintering period, intertillage and loosening the soil can be done 2-3 times. This can greatly improve the soil structure of the rapeseed field, regulate soil moisture, help fertilizer leach downward, enhance the soil's ability to hold fertilizer and retain heat, help raise soil temperature, prevent plant lodging, and also reduce weed damage and damage from sclerotinia stem rot. The depth of intertillage should vary according to the different growth conditions of the rapeseed. Generally, it should be shallow first and then deep. Fields with vigorous growth can be hoed somewhat deeper, while fields with weaker growth should be hoed shallowly.

3. Drainage and irrigation

Before winter, the three ditches should be opened well, and the field should be cleared of accumulated water in time to reduce field humidity, promote root growth and development, and help reduce low-temperature frost damage. Before overwintering, one irrigation of overwintering water is needed, which can stabilize soil temperature, provide sufficient water for rapeseed throughout the overwintering period, and also avoid a large drop in low temperature, alleviate frost damage, and effectively prevent dry freezing of the soil. When irrigating with sealing-freezing water, it must be irrigated thoroughly, irrigated and drained as you go, and the soil should be kept moist. Sealing-freezing water is suitable for the middle of a sunny day, so as to avoid the soil surface settling down, ensuring that the roots and soil are closely connected.

4. Remedial measures after freezing

After the winter cold wave, you should check the seedlings in time. For rapeseed that shows root exposure, you should promptly break up the soil and hill it around the roots to avoid broken roots and dead seedlings. On rainy and snowy days, accumulated water should be drained in time to prevent water accumulation from hindering root growth and development. At the same time, when thawing, plant ash or burnt soil ash should be spread, and clean water should be sprayed on the leaves in time to ease water imbalance, so as to prevent seedlings from losing water and dying. After the soil thaws, fertilizer should be applied in time to promote branching and increase the fruiting positions. Frost-damaged bolt buds and leaves should be removed in time.

The above is an introduction to measures for protecting rapeseed seedlings through winter. We hope it can help you. If you want to learn more related knowledge, please follow us.