Planting techniques of rapeseed

Cultivate strong seedlings

1. Select improved varieties: according to the local cultivation system and climatic conditions, combined with the local soil fertility level and production situation, select varieties with strong stress resistance and high yield.

2. Make a good seedbed: the nursery bed should be ventilated and sunny, the soil is fertile and loose, and the land near the water source is fine. Seedbed preparation is required to be "flat", "fine" and "solid".

3. Sowing at the right time: rape is very sensitive to sowing date. Therefore, determining the sowing date is an important issue in the cultivation of rape. Rape sprouting and rooting and long leaves all need certain temperature conditions. The optimum temperature for germination needs 16-22 ℃ per day, and the leaf emergence of seedlings needs more than 10-15 ℃. In addition, it is also necessary to ensure that there is at least 40-50 days of effective growth period after transplanting before entering the overwintering.

4. Nursery bed management: the day before transplanting, the "starting water" should be poured thoroughly to facilitate the pulling of seedlings and less damage to the roots. In fertilizer operation, we should grasp the principle of "front promotion, middle control and post stability". On the basis of applying sufficient base fertilizer before sowing, the three-leaf stage combined with fixed seedlings and good seedling fertilizer, generally 20-30 piculs of water and manure per mu or 2-3 kg of urea per mu to promote leaf opening and seedling emergence. 5-6 days before transplanting, 7.5 kg urea per mu was applied as starting fertilizer, which was beneficial to early seedling development after planting. Timely prevention and control of diseases and insect pests, aphids and cabbage insects are the main pests in rape seedling field, and timely drug control should be used. At the same time, weeds around the seedbed should be removed in order to reduce insect sources, and "stand-up medicine" should be fully used 3-4 days before transplanting to prevent pests from entering the field.

Timely transplanting

1. Applying sufficient base fertilizer: rape plant is tall and needs a lot of fertilizer, so we should pay attention to the application of base fertilizer, insufficient base fertilizer and thin seedlings, which will affect the plant growth and even the economic yield of rape. The base fertilizer is mainly organic fertilizer, supplemented by chemical fertilizer, which lays a good foundation for rape to need fertilizer all its life. Generally, 2000 kg of organic fertilizer, 45% of general compound fertilizer 25-30 kg or 36% of compound fertilizer (15-10-11) 30-40 kg and boron fertilizer 0.5-1 kg are applied per mu. Application method: combine ploughing and ploughing and deep application of organic fertilizer, compound fertilizer and boron fertilizer, do not fertilize too shallow, so as not to cause rape to lose fertilizer in the middle and later stage.

2. Timely transplanting: reasonable close planting, seedling age 30-35 days, 5-6 green leaves and 5-6 mm root thickness, large and strong seedlings with soil, fertilizer and medicine, but not high-foot seedlings, bent-foot seedlings and thin disease seedlings. Transplanting specification 50cm × 20cm, planting about 7000 plants per mu, transplanting while covering soil, watering root water in time after transplanting, checking deficiency and replenishing seedlings 3 days after transplanting.

Reasonable topdressing

1. Seedling fertilizer: early application, frequent application of seedling fertilizer, timely supply of nutrients needed for rape seedling stage, the use of a short period of higher temperature before winter to promote the growth of rape, to achieve strong seedlings to survive the winter, and lay the foundation for high and stable yield of rape. Seedling fertilizer can be divided into early seedling stage and late seedling stage. The fertilizer in the early stage of seedling is applied when the seedling is fixed or 5 true leaves, generally applying 5-6 kg urea per mu, in the soil lacking phosphorus and potassium, if the base fertilizer is not applied phosphorus and potassium fertilizer, phosphorus and potassium fertilizer should be applied; topdressing in the later stage of seedling should depend on seedling condition and climate. Generally, 8-10 kg of high nitrogen compound fertilizer is applied per mu. The varieties with strong spring or the warmer areas in winter should be applied early, and the low temperature in winter or triple-cropping rape should be applied late.

2. Bolting fertilizer: the bolting stage of rape is the period of vegetative growth and reproductive growth, the plant bolting rapidly, long branches, the increase of leaf area and the differentiation of flower buds, which is not only the period that needs the most fertilizer, but also the key period of increasing branches and pods. Therefore, bolting fertilizer should be applied steadily according to the application and growth of base fertilizer and seedling fertilizer. Basal and seedling fertilizer is sufficient, plant growth is robust, and bolting fertilizer can be applied little or not; if basal and seedling fertilizer is insufficient, bolting fertilizer should be applied early if there is a tendency to de-fertilize. Generally, 15-20 kg of high nitrogen compound fertilizer is applied per mu. Fertilization time is generally in the middle of bolting, bolting height of 15-30 cm is better. But those with weak growth can be fertilized at the initial stage of bolting to avoid premature senility; those with strong growth can be applied at the later stage of bolting, when the bolting height is 30-50 cm, so as to avoid blooming and causing canopy.

3. Flower fertilizer: rape blossoms and bears pods after bolting, and the number and weight of seeds are closely related to the nutritional conditions after flowering. For vigorous growth, large amount of fertilizer can not be applied or less applied at bolting stage; no fertilizer is applied to early-maturing varieties, or less at the initial flowering stage; topdressing at flowering stage can be foliar spraying, and 0.1-0.2% urea or 0.2% potassium dihydrogen phosphate is sprayed at flowering and podding stage. In addition, 0.2% borax aqueous solution can be sprayed once in the late seedling stage and bolting stage to prevent the phenomenon of "flowering but unfruitful" and increase the yield.

Irrigation and drainage

Rational irrigation and drainage is an important measure to ensure high and stable yield of rape. Rape has a long growth period, large nutrition, luxuriant leaves, many fruiting organs, and a large amount of water in its lifetime. Rape producing areas generally have less rainfall in autumn, winter and spring, and the soil is dry, which is not conducive to sowing seedlings and cultivating strong seedlings. The winter drought in the northern region often aggravates the frost injury and causes dead seedlings. There were more Rain Water in the southern region in the later period, resulting in waterlogging or waterlogging damage. Therefore, according to the characteristics of water demand of rape, irrigation and drainage should be carried out in time according to local conditions.