Planting method of greenhouse vegetables

In recent years, more and more farmers have begun to explore and try to grow vegetables in greenhouses! However, there is still a lot of professional knowledge to learn. Let me introduce some noteworthy points in greenhouse planting.

Greenhouse vegetable planting method

Plastic film vegetable planting in greenhouse is one of the effective means to increase farmers' income by artificially creating a suitable ecological environment, adjusting vegetable production season and market demand, and promoting high quality and high yield of vegetables. From the survey of most farmers who grow vegetables in greenhouses, the benefits are obvious. However, some farmers grow vegetables in greenhouses, except for the variety of vegetables, and the effect is not ideal. Four evils? Constraints are often important factors that cause losses. So-called? Four evils? Namely, fertilizer damage, drug damage, drought damage and continuous cropping obstacle.

First, fat damage. In fact, it is the harm of salt accumulation, mainly due to the salinization of soil caused by partial application of chemical fertilizer or excessive fertilization. Problems caused by fertilizer damage: first, inhibit the root development of vegetables and weaken the function of absorbing water and fertilizer; Second, the concentration of soil solution is too high, which leads to reverse osmosis of vegetable plants, leading to physiological wilting or leaf edge scorching; The third is the harm of toxic gases; The fourth is to cause plant element deficiency.

Second, plant toxicity. The toxicity is obvious and the symptoms are obvious. Potential phytotoxicity, latent symptoms or extension to the next crop of vegetables. The causes of phytotoxicity are: first, the wrong choice of pesticide varieties or improper use of herbicides; Second, the application concentration is too large; The third is to buy inferior pesticides; Fourth, it is not avoided to be used in high temperature season. After phytotoxicity, some vegetable leaves turn green rapidly; Some produce focal spots and perforations; Some leaves, flowers, fruits or deformities appear; The most serious whole plant withered.

Third, drought. It is one of the most critical factors restricting the development of greenhouse vegetables. The reasons are as follows: first, the location of vegetable greenhouses is improper, and local water sources are lacking; Second, although there is water source, the water quality is poor; Third, there is sufficient water, but ditches, canals and irrigation facilities are not matched. It is difficult to draw water, but it is sighing. Drought disaster not only affects the timely sowing and seedling safety of vegetables, but also affects the normal growth of vegetables, and brings great difficulties to the management of fertilization and pesticide application of vegetables. The effects of drought sometimes exceed those of fertilizers and drugs.

Fourth, continuous cropping obstacles. That is, in the same greenhouse, the same category or the same vegetable is planted every year or every quarter, and the yield and product quality are declining year by year. The reasons for the obstacles are: first, the same vegetable prefers a certain nutrient element, and if it is not supplemented in time, it is prone to element deficiency; Second, the accumulation of soil pathogens causes diseases and leads to dead seedlings, such as Fusarium wilt and Fusarium wilt; Third, the substances secreted by the roots of the same vegetable can easily lead to the imbalance of soil microbial community structure and cause soil aging.

Therefore, in order to produce more high-quality vegetables in plastic greenhouses, we should sum up experiences and lessons in time and take effective measures in the process of greenhouse site selection and production.

First of all, we should choose a good shed site and improve the water system. Before determining the greenhouse, it is necessary to check whether there is enough water source at the shed site and whether the water source is polluted. With enough water, we must open ditches to facilitate water diversion and drainage. If conditions permit, each greenhouse should be equipped with a water supply faucet. High standards should also be equipped with sprinkler irrigation facilities.

Secondly, it is necessary to balance fertilization and promote the stable growth of vegetables. First, apply fully decomposed organic farmyard manure all the year round; The second is to apply refined organic fertilizer and high-energy organic fertilizer, such as Ye Meifeng and Guo Meifeng; Third, it is necessary to change the partial application of nitrogen and phosphorus into reducing nitrogen, stabilizing phosphorus and increasing potassium, and applying trace fertilizer; Fourth, fertilization needs to be divided into several stages; Fifth, if fertilizer damage occurs in one day, various active liquid fertilizers should be sprayed to reduce the damage.

Thirdly, we should use drugs scientifically to ensure the safety of vegetables. First, slight phytotoxicity occurs, and the normal fertility function of vegetables can be restored by strengthening fertilizer and water management; Second, we should choose the right pesticides, especially herbicides, and use them carefully; Third, control the dosage and concentration of pesticides, while avoiding the repeated use of a pesticide; Fourth, avoid mixing pesticides at will; Fifth, high temperature should be avoided in application; Sixth, the instruments that have been applied with herbicides must be cleaned before they can be used again.

The fourth is to rotate crops and adjust the vegetable cultivation environment. First, eggplant, tomatoes and melons are prone to diseases, and other vegetable varieties should be replaced in different years or seasons; Second, it is necessary to apply more organic fertilizer to improve the soil that is prone to repeated obstacles in greenhouses; Third, choose soil continuous cropping agent to inhibit germs; The fourth is to replenish the missing nutrients for the soil lacking elements in time.

Planting forms of vegetables in greenhouse

Natsuna in spring.

Early-maturing cultivation of eggplant and melon vegetables [1] is the most common project in greenhouse cultivation. Open field cultivation is generally planted from late March to mid-April, and harvested from early May to July. Greenhouse cultivation can be planted in1-March in advance and harvested from late March to July. Early listing, high yield, long flowering and fruiting period and obvious economic benefits. In addition, according to the market demand, we can sow amaranth, auricularia auricula and spinach isothermal green leafy vegetables in advance and put them on the market in advance.

Delayed culture

The general harvesting period of delayed cultivation in autumn and winter in Natsuna is10 ~12. If preserved, it can be extended to the Spring Festival, with high economic benefits.

Leafy vegetables

In addition to melons, eggplant and other tall vegetables, there are leafy vegetables with high economic value such as auricularia auricula, spinach, celery and lettuce in the greenhouse. It can be cultivated in advance in spring and overwintering in autumn to avoid freezing injury, promote growth, increase production and supply, and go on the market out of season, with good economic benefits.

Thermophilic leafy vegetables, such as auricularia auricula and water spinach, can be planted in greenhouse in September-10, covered with heat preservation in the later period, put on the market in advance, and cooperate with conventional cultivation to basically realize annual supply. Lettuce and other vegetables like cold, but they are not very frost-resistant. It is best to plant them in the open air from the end of August to the beginning of September and from March to April in spring. If it is planted from June 165438+ 10 to March of the following year, it will be cultivated in the greenhouse.

cultivation by setting seedlings

From late June to early August, strong light, high temperature, thunderstorm and typhoon rainstorm in southern China seriously affected vegetable production and early autumn vegetable seedling. In recent years, the application of sunshade nets and non-woven fabrics has promoted the role of greenhouse in seedling raising and cultivation in summer.

Matters needing attention in greenhouse vegetable planting

I. Types and hazards of harmful gases

1, ammonia gas and nitrous acid gas mainly come from nitrogen fertilizer and organic fertilizer applied to the soil, especially in the case of excessive fertilization and soil drought, when the fertilizer encounters high temperature in the shed, it will decompose in a short time and produce a lot of ammonia gas. When the concentration of ammonia exceeds 5ppm, some sensitive vegetables such as cucumbers and tomatoes will be damaged. At first, the leaves turned brown after drying, as if they had been scalded by boiling water. When the concentration of ammonia reaches 4%, the vegetable seedlings will die after 24 hours. When the content of nitrite gas in the air reaches 2-3ppm, it will harm sensitive vegetables such as eggplant, tomato and pepper, and its symptoms mainly occur on leaves near the ground, and rarely harm new leaves. At first, it was like being scalded by boiling water. Later, due to the acidification of nitrite, the veins gradually turned white, and in severe cases, only the veins were left, and the mesophyll bleached and died.

2. When the plastic greenhouse containing carbon monoxide and sulfur dioxide gas is heated by coal fire, a large amount of carbon monoxide and sulfur dioxide gas will often be produced due to incomplete combustion or unsmooth flue. The harm of these two gases can be divided into three types: first, hidden poisoning, vegetables themselves have no obvious damage, but the assimilation function is reduced and the quality is worse, which generally has little effect on yield; Second, chronic poisoning, gas invades from the stomata on the back of leaves, brown spots appear in and around the stomata, and the surface is yellow; The third is acute poisoning, which produces whitening symptoms similar to the harm of nitrous acid gas.

3. Toxic gas emitted by plastic film itself Some plastic films will produce some volatile substances, such as ethylene and chlorine. It can invade plants through stomata or water holes on leaves, destroy cell tissues and chloroplasts, weaken photosynthesis obviously and seriously affect the yield and quality of vegetables. According to some data, when the concentration of chlorine in the air reaches 0. 1ppm, radish will be damaged after 2 hours of contact, and the concentration reaches 0.5-0.8ppm, and most vegetables will be damaged after only 4 hours of contact. At first, white or light brown irregular spots or lumps will appear between the veins, and in severe cases, the whole leaf will turn white or even fall off. When the concentration of ethylene gas in the protected field reaches above 1ppm, it can make the leaves between the veins of vegetables turn yellow, and then turn white until they die. According to experimental observation, ethylene can also make the leaves of many vegetables droop and inhibit tomato seedlings; In the concentration range of 0. 1-3ppm, the flowers, buds, young fruits and leaves of tomatoes and eggplant will fall off abnormally.

In addition, excessive use of aerosol pesticides in greenhouses will also do harm to vegetables.

Second, prevention and control measures

The harmful gas in the greenhouse not only affects the growth and development of vegetables, but also directly harms the health of vegetable farmers. Therefore, we must take active measures to prevent and control it.

1, scientific fertilization of greenhouse vegetables, should be based on high-quality soil mixed fertilizer, appropriate increase in phosphorus, potassium fertilizer, appropriate increase in nitrogen fertilizer, and adhere to the base fertilizer as the main, supplemented by topdressing. Topdressing should be strictly observed? How many times? The principle of preventing excessive fertilization. Topdressing method adopts furrowing and deep application, and then it is tightly covered with soil and watered in time to dilute the fertilizer.

2. Ventilation in time. When the temperature is high at noon, open the vent to make the air circulate; Even on cloudy or snowy days, it is necessary to ventilate for a short time at noon to reduce harmful gases and air humidity in the shed as much as possible.

3. When using coal fire to heat the plastic greenhouse, reduce the source of toxic gas, make the fuel burn fully as far as possible, and install a chimney on the stove to guide the harmful gas out of the greenhouse.