High-yield cultivation techniques of winter maize: pay attention to temperature and select varieties

Winter corn

Winter corn is the corn sown from late October to November of that year and harvested from April to May next year. The characteristics of its growth and development are as follows: the root system is poor, the ability of absorbing water and fertilizer is weak, and its growth and development is not as vigorous as that of summer sowing maize. Our province is suitable for planting winter corn below 1300 meters above sea level and in the low-heat valley of the Jinsha River. Summing up the high-yield experience of Dongyulai in various places, we should pay attention to the key technical links in cultivation, such as selection of improved varieties, timely sowing, plastic film mulching, specification planting, water and fertilizer management and disease, pest, grass and rodent control.

First, growth and development characteristics. Winter maize is an off-season crop with poor root development, weak ability to absorb water and fertilizer, and its growth and development is not as vigorous as that of summer sowing corn. In addition, winter corn is afraid of frost, such as frost during the growing period, the yield will be reduced if it is light, and the grain will not be harvested if it is heavy. Therefore, the first is to choose frost-free areas to plant winter corn, and the other is to understand the period of local minimum temperature and arrange the sowing date.

Second, do a good job of technical training. It is rare for farmers to harvest corn and sow again soon. For this reason, technical training is very important. The field should be used as the classroom in the training, and the demonstration effect is the best while talking and operating. Technical training is carried out in stages, that is, the first phase is the sowing date. The second stage is the topdressing stage of inter-seedling and fixed seedling. The third stage is the period of disease prevention, insect prevention and frost prevention.

Third, sowing specifications and density. The sowing specification and density were determined according to the growth characteristics, climate characteristics and fertilization level of winter corn.

1. Variety selection

On the premise that the planting of winter corn does not affect the planting of spring, we should try to select early and medium-maturing varieties, such as Zadan series, Zhongdan series and so on.

two。 Grasp the sowing date well

Due to the low temperature in winter, the growth period of winter sowing corn is 30-50 days longer than that of summer sowing corn. In addition, the pollination period of corn will miss the local lowest air temperature period. According to meteorological data, the lowest temperature over the years is in the early and middle of January. In order to make winter corn suffer less or no frost damage, winter corn sowing season should be comprehensively considered, usually from October to November.

3. Sowing specification and density

For the high-yield cultivation of winter maize, the sowing specification is the standard cultivation of wide and narrow rows, and the compound belt of wide and narrow rows depends on single cropping or intercropping. Single cropping, narrow row 50 cm, narrow row 2 rows of corn, row spacing 40 cm, plant spacing 13 cm 17 cm, wide row 90 cm 93 cm, seedling 5580 cm 7140 per mu; intercropping, narrow row 42 cm, 2 rows of corn, row spacing 33 cm, plant spacing 13 cm 17 cm, wide row 133 cm, wide interrow 3 rows of soybean or 2 rows of potatoes, corn seedlings have 5700 plants per mu.

Fourth, soil preparation and sowing.

The fields that plan to plant winter corn must be drained by ditches, ploughed and sunburned in time after grain harvest, raked by tractors at the right time, ditched and divided according to the size of the fields, and then sowing ditches according to the width and narrow rows and plant row spacing to carry out directional wet direct seeding, 2 corn seeds per pond and 1 seedling. The soybean row spacing is 3340 cm, the pond spacing is 1317 cm, and each pond is sown with 2 grains. Whether it is corn or soybean, the seeds should be pressed into the slate soil when sowing, so that the seeds can fully absorb water and reach the whole seedling.

Fifth, fertilize.

The fertilizer for winter corn requires the combined application of nitrogen, phosphorus and potassium, and the application of farm manure and zinc fertilizer. Mu dosage: no less than 40 kg of nitrogen fertilizer, 50 kg of phosphate fertilizer, 20-25 kg of potash fertilizer, 1 kg of zinc fertilizer and more than 1 ton of farm manure. The base fertilizer should be applied between the two ponds of corn, and the fertilizer should avoid contact with seeds. When topdressing fertilizer for the first time, the seedling height was 4-5 leaves and 10 kg urea per mu. For the second time, the seedling height was 6 to 7 leaves, 20 kg of urea, 20 kg of phosphate fertilizer and 10 kg of potash fertilizer per mu. The third topdressing is at the full heading stage, 5 kg urea per mu, it is best to use topdressing gun.

Sixth, cover the film.

Because of the low temperature, the field capacity of winter corn decreases with the end of rainy season, less rainfall and more wind. For this reason, it is very important to increase temperature and moisture by covering the film. The relevant experimental data show that the yield of winter corn is more than twice as high as that without plastic film mulching. The field block covered with film requires that the soil block should be fine, the field block should be leveled, the film should be tight when covering the film, and the cover soil around the film should be pressed but should not be covered too much. There are two ways of sowing: one is to cover the film after sowing, which can be oriented, the seeds can be pressed to the raw soil, the seedling emergence rate is high, and the orientation rate can reach more than 90%. However, attention should be paid to breaking the membrane about 5 days after sowing, otherwise it will cause burning seedlings. The second is to first open a ditch to fertilize and cover the soil, then cover the film, and then use the sharp pile to break the film to make a hole to sow, and cover the hole with fine soil after sowing. This sowing type can reduce the working time of breaking the film, avoid burning seedlings and ensure the whole seedling, but the orientation rate is relatively low.

7. Field management.

Only 30% of the work is completed at the end of sowing, while 70% has to be implemented within 4-5 months after sowing. First, if the soil is too dry after sowing, the emergence water should be irrigated once to make it reach the whole seedling, and irrigation should be carried out according to the soil water content in the middle and later stage. The second is to break the membrane in time, check seedlings, replenish seedlings, and fix seedlings. Third, according to the amount of base fertilizer and seedling potential timely topdressing. Fourth, winter corn is often harmful to rats, corn borer, and ground tigers, so it is necessary to do a good job in disease prevention, insect prevention, and rodent prevention. Fifth, do a good job of fumigation and frost prevention by stacking weeds in the corner of the field, and ignite smoke and frost in time when low temperature appears. In particular, low-concave fields should be on guard, and antifreeze should be sprayed before low temperature.