Hydroponic cultivation method of vegetables
Selection of water source:
Since it is hydroponics, we must first understand and choose water. In cities, the available water is mainly tap water and rainwater. There may be springs and streams near the hills, and there may be wells and ponds in the suburbs. Because the geological and air environment varies greatly from place to place, it is best to use tap water for hydroponics for safety reasons.
There are unreliable and uncontrollable factors in water from other sources, which affect the effect of hydroponics. Try not to use it. For example, spring water and well water can contain more minerals, and even the minerals needed by plants can't be used because their contents can't be detected, for fear of affecting the PH value or the balance of nutrients during hydroponics. Stream, pond water, rainwater and well water with high water level may contain mixed bacteria or spores of algae and bacteria, which may lead to the growth of green algae or other diseases in hydroponic devices.
Rainwater in places with serious air pollution cannot be used because it dissolves some pollutants or absorbs spores of algae and bacteria during the landing. It is estimated that the air in most cities in China is not so good, so rain is not advocated.
Note: Tap water should also be prevented from secondary pollution. Many water pipes have problems in material, and the metal parts (pipe walls or faucets) are easy to rust, and the effluent is light yellow. Such water will also invalidate the precipitation of nutrients. So don't use the water released when you get up in the morning.
oxygen supply
The key of hydroponics technology is to provide oxygen to the roots of plants soaked in water. If the roots of plants are like fish, they also need to breathe in water to generate energy for physiological activities. Field crops should be cultivated frequently, and one of its functions is to make the soil fluffy and make fresh air flow into the soil of plant roots more easily.
Because there are no tiny gaps in the soil for air to enter, water can only be transported out by dissolving air. How to make roots breathe well is how to improve dissolved air (dissolved oxygen) in water. There are many ways to increase the oxygen content in water, and the lowest cost is to make the water move. In the process of flowing, the bottom water turns up and reaches the surface to dissolve air. Therefore, it is necessary to pump water circularly. However, the water in the hydroponic container flows slowly, and the rotation speed/flow rate of the water pump is often relatively large, so it is necessary to stop the water pump, which requires the circulation control switch to start the water pump at short intervals.
Cultivation techniques of vegetables in hydroponics
First, the significance of hydroponics of leafy vegetables Most leafy vegetables are hydroponics for the following reasons:
1. leafy vegetables with good product quality eat the stems and leaves of many plants, such as lettuce and chicory, mainly raw, which requires the products to be fresh, clean and pollution-free. Vegetables in Shi Pei are easy to be polluted and stained with soil, which is not convenient to clean. However, hydroponic leafy vegetables are better in quality, clean and tender, and have a good taste, which is superior to local leafy vegetables.
2. In order to meet the market demand, annual cultivation can be carried out in the same place. Leafy vegetables are not easy to store, but they need to be produced all the year round to meet the market demand. The stubble-changing operation of soil-cultivated leafy vegetables is complicated, which requires soil preparation, border planting, fertilization, watering and other operations, while the stubble-changing operation of soilless culture is very simple, just planting seedlings, such as lettuce, in planting holes, and sowing, planting and harvesting can be carried out every day for 365 days a year. Continuous production without interruption. Therefore, hydroponics is convenient for stubble arrangement and suitable for planned and contract production.
3. A good production method to solve the problem of vegetable supply in off-season. Generally, leafy vegetables are short, so there is no need to increase supporting facilities, so the investment in facilities is less than that in soilless culture of fruits and vegetables. Hydroponic vegetables have short growth cycle and fast turnover. Hydroponics is a kind of facility production, which is generally not easy to be damaged by typhoons. Farmers who can supply fresh vegetables in coastal areas during typhoon season often get higher profits.
4. There is no need to change the nutrient solution halfway, which saves fertilizer. Because of the short growth cycle of leafy vegetables, if no major physiological diseases occur in the middle, it is generally only necessary to prepare nutrient solution once from planting to harvesting, and there is no need to replace nutrient solution in the middle. Because of the long growth period of fruits and vegetables, even if there are no major physiological diseases, in order to ensure the balance of nutrients in the nutrient solution, it is necessary to update the nutrient solution in half or in full.
5. The economic benefit of hydroponic leafy vegetables is high, which can avoid continuous cropping obstacles and has high multiple cropping index. The operation rate of facilities is as high as more than 20 crops a year, and the economic benefits of production are high. Therefore, leafy vegetables are often cultivated by hydroponics.
Second, the structure of hydroponics facilities Beijing Vegetable Research Center developed DFT hydroponics facilities by introducing and learning from foreign hydroponics facilities and combining with the actual economic level of China. The facility consists of five parts: nutrient solution tank, cultivation bed, liquid adding system, liquid drainage system and circulation system, which are introduced as follows.
1. nutrient solution tank nutrient solution tank is a device for storing nutrient solution, which is generally made of brick and cement and placed underground. Because of the large capacity of this nutrient solution tank, the temperature of nutrient solution does not change much in winter or summer. However, the use of nutrient solution tank must rely on the power of pump to replenish liquid, so it must be used where there is power supply. The volume of nutrient solution tank, generally 667m2 hydroponic area, needs 5? The standard design of 7t water, the specific width can be flexibly designed according to the greenhouse terrain. The construction of nutrient solution tank is a highly technical work. Generally made of brick and cement, it can also be made of reinforced cement. In order to prevent the water tank from leaking, seeping and backwater, anti-seepage materials must be added during construction, and the inner wall of the water tank should be coated with water-removing materials. In addition, in order to facilitate the cleaning of the liquid tank and maintain a certain amount of water in the water pump, a small water tank of 20cm square should be made at the water pump in the corner of the liquid tank in the design and construction to clean the nutrient solution tank.
2. Cultivation bed is the place where crops grow and the main part of hydroponic facilities. The roots of crops are fixed and supported on the bed, and water, nutrients and oxygen are obtained from the cultivation bed. A cultivation bed consists of a bed body and a planting plate (also called a cultivation plate). (l) The bed body is a device for containing nutrient solution and planting crops. The bed body of the cultivation bed is made of polystyrene. There are two specifications of the bed, one is 75cm long, 96cm wide and 17cm high. The other is 100cm long, 66cm wide and 17cm high. These two specifications are used together according to the span of the greenhouse. The bed made of this polystyrene material has the characteristics of light weight and easy assembly, and its service life is as long as 10 year. In order to prevent the nutrient solution from leaking and protect the bed, a black film with a thickness of 0. 15mm and a width of 1.45m was laid inside. (2) The cultivation tray is used to fix the root system, prevent dust from invading, block light from entering, prevent algae from growing, and keep the temperature of nutrient solution in the bed stable. The cultivation board is also a polystyrene board, which is 89cm long, 59cm wide and 3cm thick. There are planting holes with a diameter of 3cm, and the spacing between the holes is 8cm? 12cm. The plant spacing can be adjusted according to the needs of different crops. The service life of the cultivation board is also more than 10 years.
3. Liquid supply device and nutrient solution circulating hydroponics facilities are usually pumped into the cultivation bed by water pump. Keep 5 in bed? At the water level of 8 cm deep, the liquid feeding facility of the cultivation bed consists of a main liquid feeding pipe made of iron or plastic and a branch liquid feeding pipe made of plastic, and the plastic branch pipe has a hole with a diameter of 3 mm every 1.5 m, and the nutrient solution flows into the cultivation bed through the small hole. The circulation mode of nutrient solution is that the nutrient solution is pumped out of the nutrient solution tank by the water pump, enters the cultivation bed through the main liquid adding pipe and the sub-liquid adding pipe, and is absorbed by the roots of crops. The nutrient solution higher than the drainage outlet flows back to the nutrient solution tank through the drainage ditch along the drainage outlet to complete a cycle. 3. Varieties of leafy vegetables suitable for hydroponics There are many varieties of leafy vegetables suitable for hydroponics. The varieties of leafy vegetables suitable for hydroponics successfully tested by Beijing Vegetable Research Center include lettuce, chicory, Chinese kale, Chinese cabbage, shepherd's purse, large leaf mustard, kale, cabbage, watercress, cress, celery, clover celery, amaranth and leek.
Planting methods of common vegetables
Planting method of garlic
1. Fine soil preparation. Garlic is best planted on fertile, soft and well-drained sandy soil, and continuous cropping should be avoided as far as possible. Generally, deep tillage 15 ~ 20cm, combined with deep tillage, apply manure 1000 ~ 1500kg, build a ridge of about 2m, dig a drainage ditch, and keep the ridge smooth and soft.
2. Sow at the right time. Garlic should be planted from the first ten days of September to the first ten days of 10; No later than1mid-October. Planting green garlic is best in the middle and late August. Sowing is carried out in holes, 2 per hole? 3 petals, spacing 17? 20 cm, keeping the depth at 0.02-0.3 m, covering with a layer of plant ash or pouring with a layer of mud after sowing. Sowing amount per mu 120? 140 kg. Attention should be paid to selecting varieties with strong resistance.
3. Fertilization management.
(1) base fertilizer: Before soil preparation, apply 20-25kg ammonium bicarbonate, 8 8- 10/0kg calcium superphosphate and 4-5kg potassium chloride or15-20kg compound fertilizer per mu.
(2) Seedling fertilizer: at the beginning of the third leaf after the whole seedling, apply 1500 ~ 2000 kg of livestock manure and urine per mu, and add 5 kg of urea.
(3) Wax fertilizer: The so-called wax fertilizer is a supplementary fertilizer applied to crops from this winter to the next spring. Ammonium bicarbonate 100 kg, human and animal manure 1000 kg per mu? 1200 kg.
(4) Bolting fertilizer: at the bolting stage of garlic, urea 15 kg was applied per mu.
(5) Foliar spraying: during the rapid expansion period of garlic, 0.2 ~ 0.3% potassium dihydrogen phosphate solution is sprayed per mu, preferably around Grain Rain.
4. On-site management. After all the garlic seedlings are planted, move and fix the seedlings with bamboo pieces. After fertilization, loosen the soil and weed in time. Loosen the soil once before and after the severe cold, and dredge the drainage ditch in time in late February of the following spring. In case of drought, furrow irrigation should be carried out in time to combat drought.
5. Control pests and diseases. The main pests and diseases of garlic are Fusarium wilt and coffee bean weevil. Spraying 50 kilograms of 25% carbendazim 100 grams of water per mu to control the epidemic; Can garlic coffee beans be used as aluminum phosphide 3 per cubic meter? 5g fumigation control.
6. Harvest in time. Garlic seedlings are usually harvested from early April to early May. When the upper part of the garlic bolt bends downward or the top of the leaf is pulled out by 0. 1 m, it should be harvested in time, cut the garlic bolt clean, and then spread it in the sun for 2? 4 days, and then stored. ?
Planting method of green vegetables
1. Choose clods: choose paddy fields and dry lands with deep soil layers, good irrigation conditions and no pollution to soil, water quality and air.
2. Selection of improved varieties: make full use of the advantages of local farmers' green vegetable varieties, select the original seeds of healthy green vegetables without diseases and insects, purify and rejuvenate them, and provide them uniformly.
3. Sowing in time: Generally, the first half of 10 is the best sowing date, and Kugaji after soybean and peanut harvest is the seedbed. Raise seedlings according to the ratio of seedbed to field of 1:7, so that the bed soil is fine and flat.
4. Reasonable close planting: seedlings should be transplanted 30 days later and in mid-June165438+1October. The average row spacing is 66.7 cm, the plant spacing is 33.3 cm, and the yield per mu is 3000 plants. If the soil is fertile, seedlings should be transplanted in the early and late stages of cloudy or sunny days, and after planting, root water should be poured 1 time.
5. Scientific fertilization: Green vegetables are overwintering crops with long growth period and strong absorption. Fertilization for the first time 1 time is carried out 3-5 days after planting, and 500 grams of fireclay ash is applied to each plant; The second fertilization is carried out 60 days after transplantation, and diluted human feces can be applied. Vegetables are free from pests and diseases, and no pesticides are needed.