Serious errors in fertilization in greenhouses and scientific fertilizers

(I) The current practice of greenhouse greenhouse fertilization

1, too much fertilizer, organic fertilizer application is less. The cultivation of vegetables in the greenhouse has caused changes in the ecological environment. The main factors constraining the level of output have been changed from the scientific application of fertilizers and water to whether temperature regulation is reasonable or not! The amount of carbon dioxide in the indoor air is sufficient! Fertilizers are of little use to both, and organic fertilizers not only provide the crop with a variety of fertilizer elements, but more importantly, it continuously releases carbon dioxide.

2, blindly increase the amount of fertilizer, especially the excessive amount of nitrogen fertilizer. Some technicians emphasized the application of 10 cubic meters of chicken manure + 100 kilograms of diammonium + 100 kilograms of urea + 100 kilograms of cake fertilizer per 667 square meters of greenhouses when formulating the technical plan. When some farmers used fertilizer, they exceeded this amount.

What kind of application is this?

First, fresh chicken manure has a nitrogen content of 1.63%. The dry chicken manure content is even higher. In 10 cubic meters of chicken manure, it contains about 160 kg of pure nitrogen, plus the nitrogen content of diammonium and urea. The application of pure nitrogen over 200 kg, plus topdressing nitrogen fertilizer, the application of pure nitrogen can reach about 220 kg per 667 square meters, equivalent to 1300 kg of ammonium bicarbonate, equal to 26 bags of ammonium bicarbonate Mushi ah!

Second, vegetable plots, especially old vegetable plots, have a high level of soil nutrient content, especially nitrogen content, due to a large number of fertilizations over a long period of time. As a result of laboratory tests, the total nitrogen (N) content is generally around 0.1%. Alkaline nitrogen (N) 100 mg/kg - 200 mg/kg. In 25 cm deep plowing layer soil, the total nitrogen content can be 200 kg/667 m2, and the available nitrogen can reach 220 kg/667 m2, which is ten to several dozen times that of vegetables actually absorbing nitrogen fertilizer.

This not only drastically increased production costs and caused waste; more seriously, it greatly increased the soil solution concentration and alkalized the soil. After the planting of the crop, the light will not develop roots, delay fertility, and grow unevenly; when it is severe, it will cause burning of roots, burning of leaves, and even a large number of dead seedlings.

Excessive nitrogen content in the soil can also cause plant growth and delay the results. At the same time, too much nitrogen fertilizer can inhibit the absorption of potassium, calcium, magnesium, iron, zinc and other elements in the root system and induce various physiological diseases.

3, top-dressing fertilizer mainly fast-acting. Fertilizer can only provide fertilizer elements and can not release carbon dioxide. Once the concentration of carbon dioxide in the facility is reduced, the photosynthetic efficiency is reduced, and even more quick-acting fertilizers are applied, which is meaningless! Instead, it will pollute the soil and increase the content of nitrates and nitrites in crop products, making the product a carcinogenic product that is harmful to humans.

(b) Fertilization in greenhouse soils is different from soil fertigation in open soil conditions.

1. The role and purpose of fertilization have changed significantly. Soil fertigation under open environment conditions is mainly aimed at supplying crops to various fertilizer elements. In addition to the demand for various fertilizer elements for the supply of crops, soil fertilization in greenhouse cultivation is also responsible for the supply of crop photosynthesis. The main task of carbon dioxide is a major task. Because the environmental conditions of greenhouse cultivation are closed, the ventilation and convection of air is strictly limited, and it is difficult for indoor air CO2 to be replenished from the air circulation. The adequacy of carbon dioxide is the primary factor that restricts the output of indoor crops. Therefore, soil fertilization in greenhouse cultivation not only meets the demand for various fertilizer elements, but also more importantly meets the crop's demand for carbon dioxide.

2. The change of fertilization target will inevitably change with the type of fertilizer applied. In greenhouse cultivation, no matter what kind of fast-acting fertilizers are available, they cannot meet the demand of crops for carbon dioxide. Only when organic fertilizers are applied to the soil and the microbial decomposition of the soil can release carbon dioxide continuously, organic fertilizers become greenhouse fertilizers. The first choice and must. Organic fertilizers should be applied to both base fertilizers and top dressings to meet the crop's carbon dioxide demand.

3, the application method is different. In particular, after planting crops, whether it is topdressing organic fertilizers or topdressing fertilizers, it must be done on a sunny morning, so that spreading, digging, watering, and filming can be performed simultaneously, and the ventilation openings must be opened at the same time. It is strictly prohibited to carry out topdressing operations on cloudy days and in the afternoon. Otherwise, the ammonia and water vapor that the fertilizer volatilizes cannot be eliminated in time, which will seriously harm the crops. Excessive indoor humidity may also induce disease.

(III) Scientific fertilization for greenhouse vegetable cultivation

1, increase carbon dioxide gas fertilizer. The main raw materials for photosynthesis of crops are carbon dioxide (CO2) and water (H2O). Carbon dioxide (CO2) comes from the air and is continuously replenished by the circulation of air. At the same time, it also comes from the organic matter in the soil and is continuously released by the decomposition of microorganisms.

Because of its tightly sealed greenhouses, indoor air components are less affected by outdoor air circulation. This has created conditions for the addition and release of carbon dioxide (CO2) gas fertilizers in our facilities and has been realized. The addition of carbon dioxide gas fertilizers has a significant effect on the yield increase, which generally can increase production by 30-40%. There are many ways to use carbon dioxide gas fertilizers. The low production cost and easy promotion are as follows:

(1) Biogas is combusted indoors. Biogas digesters are built underground in the room. Biogas is fermented at a rate proportional to the required percentage of poultry manure and water. It is sent to the biogas furnace through plastic pipes and ignited to produce carbon dioxide gas.

(2) Sulfuric acid-ammonium bicarbonate reaction method: Hang a plastic bucket every 40-50m2 in the facility and the height of the suspension is the same as the growth point of the crop. Fill the barrel with 3-3.5 kilograms of clean water, and join slowly. 1.5-2 kilograms of concentrated sulphuric acid, dubbed about 30% of dilute sulphuric acid, after which, every morning, about half an hour after unveiling the grasshoppers, 200-400 g of bicarbonate is lightly put in each barrel filled with dilute sulphuric acid. Ammonium, sunny days and fruitful days, cloudy days and other growth stages can be added, cloudy without.

Ammonium bicarbonate should be put into a small plastic bag first. Before putting it into the acid solution, it should be placed at the bottom of the pouch, and tie 3-4 small wires with iron wire so that the sulfuric acid can enter the bag and react with ammonium bicarbonate to release carbon dioxide. The reaction equation is as follows:

2NH4HCO3+H2SO4→(NH4)2SO4+2CO2+2H2O

Use this method must pay attention to:

First, you must slowly pour sulfuric acid into clean water. Never pour clear water into sulfuric acid! In order to avoid splashing of acid, burn crops and operators.

Second, when ammonium bicarbonate is put into the barrel, gently put it in. Remember to not splash acid.

Third, the residual solution after the reaction is ammonium sulfate aqueous solution, can be added more than 10 times of fresh water for other crops used topdressing, must not be put down, so as not to waste and burn the crop.

(3) Install the carbon dioxide generator, add sulfuric acid and ammonium bicarbonate to the generator every day, and perform chemical reactions inside the generator to release carbon dioxide. The principle is the same as above.

(4) Ignition method: Between 8 and 10am every morning, use a thin, tin-free iron bucket with a thick iron wire as the grate at the bottom of the bucket. The firewood will be ignited and burned to release carbon dioxide. When it is lit, one must do: Pod oxygen and open flames are fully burned to prevent carbon monoxide and other harmful gases from harming the crops; Secondly, the stoves should be moved and burned on the indoor work path to avoid causing high-temperature roasted seedlings; Third, strictly control the burning time, 350-500 In the m2 greenhouse, the burning time must not exceed 30 minutes at a time to avoid excessive amounts of harmful gases generated during combustion, and damage crops.

Ignition method can not only produce carbon dioxide, but also can increase indoor temperature and reduce air humidity. As long as the operation is correct, the effect of increasing production and income is significant. During operation, it can be ignited twice a day, once in the evening and then lit, and once in the open grass. It ignites after about 1 hour. In the evening, the carbon dioxide emitted by burning has a greenhouse effect, which can significantly reduce indoor heat radiation, can significantly increase the indoor temperature at night, reduce the indoor air temperature, and have remarkable effects on heat preservation and disease prevention.

2, reduce the amount of basal fertilizer. First of all, greenhouses are closed facilities, indoor harmful gases can not be ruled out, such as the use of base fertilizer is too much, volatile ammonia, indoor vegetables to suffer from ammonia hazards, so that the leaves dry spots or spots, severe leaves withered until Dead tree phenomenon occurs.

Second, before the vegetables enter the fruiting period, the amount of fertilizers is only about 1/6 of the total amount of fertilizers in the whole growth period. In this period, the soil and fertilizer should not be too much, which will not only cause burning phenomenon but also cause seedlings to sprout. Prosperous, affect flower bud differentiation, delay the result period.

Third, due to the large amount of long-term fertilization in greenhouse vegetables, various nutrient elements in the soil are not lacking, and carbon dioxide is lacking. However, the demand for carbon dioxide in crops during the seedling period is very small, and it gradually increases with the increase in the number of leaves. When the results reach a peak, the demand for carbon dioxide reaches a peak. The carbon dioxide in the greenhouse is mainly derived from the decomposition of organic fertilizers in the soil. After the organic fertilizers are applied to the soil, the carbon dioxide release peak period is about 10-50 days after fertilization. A large amount of basal fertilizer will not only cause burning phenomenon, but also the amount of carbon dioxide emitted will be wasted due to the small amount of pre-reproductive crops. After entering the result period, the amount of carbon dioxide required has increased. During this period, the period of carbon dioxide release in the soil has passed, and the supply of carbon dioxide has been insufficient, which has restricted the exertion of photosynthetic efficiency and has affected the increase of production.

Therefore, the amount of basal fertilizer should not be too much, generally 2500-3000 kg of basal fertiliser per 667 meters. A large amount of organic fertilizers should be applied in succession after the flowering results in order to continuously provide enough carbon dioxide for crop photosynthesis.

3, to change the topdressing quick-acting fertilizer for biological bacteria organic fertilizer, increase the amount of organic fertilizer, increase indoor carbon dioxide content.

Although organic fertilizer has a low content of fertilizer elements, it contains the most comprehensive fertilizer elements and also contains a large amount of organic matter. The addition of organic fertilizers not only satisfies the needs of the crop for various fertilizer elements, but also significantly increases the organic matter content of the soil. Organic matter is transformed into humus (ie, humic acid, fulvic acid, and humin) by the action of microorganisms in the soil. Although the content of humus in the soil is small, the effects on the soil properties and the growth status of the plant are various:

(1) Humic substances can continuously decompose and release nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, and various trace elements, etc. to meet the demand of the growth and development of crops on mineral elements. At the same time, humus decomposition energy sources continuously release carbon dioxide, especially for severe shortage of carbon dioxide caused by less ventilation in the greenhouse, which has a great mitigation effect, thereby increasing the photosynthetic productivity of the greenhouse.

(2) Humus can improve the physical and chemical properties of soil, promote the formation of granule structure, increase soil porosity, improve ventilation, regulate the proportion of water and gas, promote soil microbial activity, and make soil warm.

(3) Humus is organic colloidal in the soil, with a large number of negative charges, can adsorb a large number of cations, such as: NHR +, K +, Ca 2+, etc., Improve soil fertility.

(4) The humus is also buffered and can regulate the pH (pH) of the soil. Because the hydrogen ions (H+) in the soil solution can be exchanged with the base ions adsorbed on the soil humus colloids, thereby reducing the acidity of the soil solution; when the hydroxide ions (OH-) in the soil solution is large, its colloidal The adsorbed hydrogen ions (H+) can in turn combine with hydroxide ions (OH-) to form water (H2O), which lowers the pH of the soil solution. Especially in salty and alkaline soils, adding organic fertilizers is one of the effective ways to improve saline-alkali land.

The sources of organic fertilizers are varied. Livestock and poultry manure, crop stalks, weed leaves, biogas residue, distiller's grains, vinegar grains, and cake fat all contain large amounts of organic matter, but they also contain many harmful substances. The soil and crops will be polluted to varying degrees, so they must be fermented and retort before use to convert harmful ingredients into harmless ones. The best tanning method is to add beneficial bacteria to the manure for fermentation, and then apply it as a bio-organic fertilizer.

After being fermented by biological bacteria, organic fertilizers contain a large number of beneficial bacteria. Not only can they convert various harmful substances in organic fertilizers into harmless ones, but they can also activate soil layers and improve soils when applied to soil. The pellet structure improves soil fertility and water storage capacity; promotes the development of crop roots; inhibits and eliminates harmful fungi in the soil and reduces disease occurrence; releases fertilizer elements that have been fixed by the soil and is reused by crop roots. Improve the utilization rate of fertilizers, reduce the amount of fertilizers used, and convert the available nitrogen into harmless organic nitrogen fertilizers. After the crops are fully grown, the products produced are also pollution-free, green, and even organic.

Different animal feces contain different proportions of various fertilizer elements. In order to provide crops with the most suitable bio-organic fertilizers, they should be properly blended with other manures and chemical fertilizers according to different nutrient contents of different manures during fermentation. Or crop stalks for deployment.

Taking chicken manure as an example: Fresh chicken manure contains 1.63% nitrogen, 1.54% phosphorus pentoxide and 0.85% potassium oxide. It is a high-quality organic fertilizer containing the most effective nutrients in various animal manures. However, its deficiency is the high ratio of nitrogen and phosphorus, and the proportion of potassium is insufficient. However, the demand for potash from the main vegetable varieties of melons and solanaceous vegetables cultivated in the facility far exceeds the demand for nitrogen. Fermentation and tanning should be properly mixed with corn stover (0.5% nitrogen, 0.4% phosphorus pentoxide and 1.6% potassium oxide) and potassium sulfate, and adjust the ratio of nitrogen, phosphorus and potassium to make it more reasonable. Suitable fertilizers for melons and solanaceous vegetables. Generally, 2000 kg of chicken manure is blended with 300 kg of corn straw and 30 kg of potassium sulfate, and 30-75 kg of an aqueous solution containing 500 g of biological bacteria and 200 g of brown sugar is sprayed and stirred, and the mixture is finally sealed with a plastic film for 15-20 days. can.

Applying basal fertilizer, 2,000 kg of chicken manure (3000 kg of swine manure and 5,000 kg of cattle and horse manure) can be applied at the end of each acre of greenhouse, and later during the result, the combined application of irrigation and application and the application of ditches in the operation About 8000 kg.

4, improve the top dressing method

(1) Topdressing organic fertilizers should be carried out in combination with irrigation and flooding, and it should be carried out in combination with furrowing in the operation. Generally, it begins at the rapid expansion of young fruit, once every 30-40 days, especially around the first half of the winter solstice, temperature and ground temperature. All will enter the coldest period. In order to raise the ground temperature, loosen the soil, supplement the soil oxygen, and ensure the supply of carbon dioxide, it is necessary to top-up organic fertilizers in the operation line, and use 2,000-2,500 kilograms of mature manure per 667m2, or to decompose them. Fecal dilute 2500-3000 kg.

Fertilizer will volatilize ammonia gas. Irrigation will increase indoor humidity. In order to prevent the occurrence of ammonia damage and increase indoor humidity and induce disease, the area of ​​top dressing should be controlled at about 1/5 of the total area of ​​the facility, with each interval of 4-5 rows. Follow one line, one time every 3-5 days, rotate operation, 30-40 days round 1 time.

Top dressing must be done in the sunny morning and open the vents. Strict implementation of trenching, sprinkling, digging, covering, watering, and cover film are performed simultaneously. It is strictly prohibited to apply fertilizer on cloudy days or in the afternoon.

Top dressing can also be carried out in combination with watering. Each time, each ditch is brewed with 3-5 kg ​​of decomposed livestock manure or 1-1.5 kg of cooked cake, once every 10-20 days.

(2) Dressing should be combined with fertility cycle. Fertility should not be top-dressed during the early period of childbirth. When the first fruit of tomato is harvested and grows to the size of hawthorn, it will be picked up (cucumber roots are sitting, eggplant, pepper, door, pepper, pepper). Apply the first fertilizer, harvest the first batch of fruit, and apply the second fertilizer. After entering the harvest period, increase the number and quantity of topdressing, and apply topdressing every 15 days. The results can be reduced later fertilizer or no trace of fertilizer material.

(3) According to its growth status, topdressing should be determined. For example, cucumber and melon seedlings grow faster. Newly-grown leaves at the growing point are larger. The leaf edges are spiny, and the nicks are clear. The leaves are bright and yellow-green, indicating that the fertilizer and water are full. On the other hand, the new hair leaves at the growth point are small, round, and missing, and the slow growth rate is a deficiency. The melon strips grow faster, have less melons, bright melons, and straight melon strips, indicating that the fertilizer is fuller. On the contrary, the melon color is dark, the melon strips are bent, and there are more slender waists, sharp-edged melons. The melon strips have a slow growth rate, and the malformed melons are much more. The melons are obviously lack of fat and should be top-dressed in time, and the amount of topdressing should be increased appropriately. Topdressing can also be followed by a small amount of quick-acting fertilizer, but it should not be used excessively and blindly increase the amount of application, so as to avoid increasing the concentration of soil solution, burning roots to kill seedlings, alkalinize the soil and cause fertilizer loss, increase production costs and cause waste.

Topdressing fertilizer must be carried out in combination with watering, about 0.3 kg per ditch, first dissolved into an aqueous solution, and then flushed with water. It is forbidden to spread and apply points (points) to prevent ammonia from evaporating and poisoning the leaves and leaves.

(4) Top dressing should be carried out in conjunction with the season. Before the winter solstice is about 10 days, a sufficient amount of organic fertilizer must be applied in the operation line, followed by topdressing once every 30 days. Since the winter solstice brought the weather into a severe cold season, the temperature dropped, especially when the ground temperature decreased more significantly, and the root activity was inhibited. In addition, the amount of ventilation was reduced, the indoor carbon dioxide was severely deficient, and the photosynthetic yield was significantly reduced. The application of sufficient organic fertilizer at this time can not only increase the ground temperature by fermentation, promote the development of roots, but also release a large amount of carbon dioxide, promote photosynthesis, greatly increase the yield during the high price period before and after Spring Festival, and significantly increase the economic benefits of greenhouses.

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