How to cultivate asparagus in spring to achieve high yield

Water spinach, also known as water spinach, water spinach or rattan vegetable, is a kind of fast-growing green leafy vegetable introduced everywhere in recent years. Its edible parts are tender stems and leaves, rich in nutrition and high in calcium. The calcium content is more than 10 times higher than that of tomatoes, ranking first in leaf vegetables, and contains more carotene, which can be used for cold salad, stir-frying or cooking soup. now it has become a home-cooked dish on the dining table of ordinary people and one of the special vegetables in hotels and restaurants.

Environmental requirements of asparagus

Asparagus prefers high temperature and humid environment. It takes more than 15 ℃ for seed germination, more than 30 ℃ for axillary bud germination, rapid and tidy sprouting, and the optimum temperature for vine leaf growth is 25-30 ℃, the higher the temperature, the stronger the vine leaf growth and the shorter the picking interval. Asparagus can withstand the high temperature of 35-40 ℃, the vine leaves below 15 ℃ grow slowly, the vine leaves below 10 ℃ stop growing, are not resistant to frost, and the stems and leaves die when exposed to frost. The cellar temperature of the rattan should be kept at 10-15 ℃ with high humidity, otherwise the rattan is easy to freeze to death or dry up.

Asparagus likes high air humidity and moist soil, the environment is too dry, the vine fiber increases, and it is too old to eat, which greatly reduces the yield and quality. Asparagus likes sufficient light, but it also has strong adaptability to close planting. Asparagus is not strict on soil conditions, but because it likes fertilizer and water, it is still better to use the soil with relatively heavy viscosity and strong water and fertility conservation. The leaf tip of asparagus grows massively and rapidly, which requires a large amount of fertilizer, strong fertilizer tolerance and a large amount of nitrogen fertilizer.

How to cultivate high yield of asparagus in spring?

1. Prepare the land and make beds.

Asparagus has fast growth rate and strong branching ability, so it needs an adequate supply of water and fertilizer. Basic fertilizer should be fully applied, generally 500-1000 kg of rotten organic fertilizer and 100 kg of plant ash per mu, evenly spread, ploughing depth of about 20 cm, so that manure and soil are fully mixed, and then make a border, 20 cm high and 1.0-1.5 m wide (covering ditch). Note that the base fertilizer should be applied a few days in advance to prevent the seedling from burning due to manure fermentation caused by film mulching.

2. Soaking seeds to accelerate germination

The seed coat of hollow cabbage seed is thick and hard, and its water absorption is slow. If it is sown directly, it will germinate slowly because of low temperature. In case of long-term low temperature and rainy weather, it will cause seed rot, so it is appropriate to accelerate germination. The seeds can be soaked in 40 ℃ 50 ℃ warm water for 30 minutes, then soaked in clean water for 16 minutes for 20 hours, picked up and washed, wrapped with gauze, and germinated under the condition of 30 ℃. Keep the seeds moist during budding, rinse the seeds with clean water once a day, and sow when the seeds are 50% white.

3. Sowing at the right time

The suitable sowing time is mid to late March, and can be sowed, striped or on demand. The amount of seeds used for sowing is about 10: 15 kg per mu, and the thickness is about 1 cm after sowing. Strip sowing can cross the border surface with a shallow trench with a depth of 2 cm and a distance of 15 cm, watering enough water at first, then sowing the seeds evenly in the ditch, and then covering with fine soil, the seed consumption per mu is 1.5 kg 2.0 kg On demand, the row spacing was 3035 cm, the hole spacing was 1520 cm, and each hole was sown with 3 seeds. Immediately after sowing, the seeds were watered and covered with soil. After covering the soil, cover the border with thin film, and cover it with grass grass, etc., in order to increase the ground temperature. During the period from sowing to emergence, the soil should be kept moist, and the mulch can be opened after emergence. When the seedling grows to 15-18 cm, it can be planted or harvested. The top tip of about 15 cm can also be cut and propagated during the growth period. Under the condition of suitable soil moisture, the shoot will soon grow adventitious roots and pull out new shoots. Water planting uses vines to raise seedlings. The vines selected last year were used to accelerate germination and then inserted into the seedling border. When the seedling height was 30 cm, the vines were pressed to promote adventitious roots downward, lateral branches were drawn upward, and then planted with side branches cut out one after another.

4. planting at the right time

Ipomoea aquatica is not strict on soil conditions and has wide adaptability. Paddy fields and gully corners can be planted in dry land, but it is best to choose clay loam soil with low topography, moist and fertile soil according to row spacing of 3035 cm and hole spacing of 15,20 cm. For water planting, it is appropriate to choose muddy fields with convenient drainage and irrigation, shade to sun and shallow water layer, with a row spacing of 20 cm, and the leaves should be above the water surface when planting.

5. Field management

Asparagus is a light-loving crop. During the growth period, sundries on the film should be removed in time to maintain sufficient light in the shed, so as to facilitate the growth of asparagus. When asparagus is cultivated in greenhouse in spring, it is extremely disadvantageous to its growth because of its low temperature, high humidity and long duration of low temperature, overcast and rain, so heat preservation and cold prevention is the key to ensure the high yield of asparagus. After sowing, the greenhouse should be sealed in time to ensure that the temperature in the greenhouse is higher than 10 ℃, while in sunny days, when the sun is sufficient and the temperature is high, ventilation and dehumidification should be done in time to avoid the temperature in the greenhouse above 35 ℃, so as to prevent plant diseases, so as to maintain the vigorous growth of plants and increase the yield. When the humidity is high in the greenhouse, the film at both ends or around must be opened in time for ventilation and dehumidification. It is necessary to plough and weed in time during the growth period, and there is no need for weeding and ploughing after ridge closure. When planting fields with water, water should be released to dry the fields to raise the ground temperature.

6. Fertilizer and water management

Asparagus is a crop harvested many times, so in addition to applying sufficient base fertilizer, it is necessary to carry out multiple stages of topdressing in order to obtain high yield, which can be combined with watering. The seedling stage can be applied with 10%-15% rare manure and urine, with a dosage of 1000 kg per mu; when 3-4 true leaves grow out of seedlings, 15-20 kg of compound fertilizer and 2-4 kg of urea are applied per mu; and 5-8 kg of compound fertilizer is applied per mu during the harvest period. Asparagus is a leafy vegetable crop, which requires a large amount of water, so it is necessary to ensure an adequate water supply and keep the soil moist by watering frequently.

7. Pest control

Adhere to the principle of "prevention first, comprehensive prevention and control", and adopt agricultural, physical, chemical and other comprehensive prevention and control measures to control the occurrence of diseases and insect pests. Timely removal of disease and debris, weeds and dead leaves in the field, strengthen the management of temperature and humidity in the field, and adopt physical measures such as yellow board and insect control net to control diseases and insect pests. The main diseases in the seedling stage of hollow cabbage are quenching disease and stem rot, which are caused by low temperature and high relative humidity. The occurrence of the disease can be reduced by reducing humidity, and chlorothalonil or methyl topiramate can be used to control. There are white rust, brown spot and mosaic disease during the growing period. White rust can be controlled by 1purl 200 Bordeaux solution, or 0.2 Baomesulphur mixture, or 50% carbendazim wettable powder 500 times solution, or 65% Dysen zinc wettable powder 500 times solution; brown spot disease can be controlled with 50% nail cream copper wettable powder 600 times 700 times, or Luheng No. 1; mosaic disease can be controlled with virus An or phytopathrin. The main pests are cabbage worm, Spodoptera litura larvae, mites and red spiders, which can be controlled with 8000 times of 50% phoxim EC, or 80% dichlorvos EC, or 20% butyl EC.

8. Timely harvest

Generally, it can be harvested 35-45 days after sowing, when the plant height of asparagus is 30-40 cm. If harvested at one time, it can be harvested and put on the market when the plant height is 20-35 cm. If harvested many times, the seedlings can be harvested at the height of 10-15 cm, and the seedlings can be put on the market when the height is 15-20 cm, and the remaining seedlings can be harvested many times. The first picking was carried out when the seedling height was about 35 cm, and there were two stem nodes on the stem, then the second stem node left by the stem and the first stem node left by the stem base were picked for the third time to promote the stem base to sprout again and keep the stem vine picked later. When picking, it is more appropriate to pick by hand, but it is easy to rust and die if iron tools such as knives and scissors are used. If there are too many branches, too dense, too thin, it should be thinned. In the initial harvest period and later growth period, it was harvested once every 7-10 days, and once in 5-7 days in the peak growth period. Generally, the yield per mu of one-time harvest can reach more than 15 kg, and the yield per mu of multiple harvest can reach more than 5000 kg.