Everyone knows that wheat is a crop that requires a lot of fertilizer. It is also necessary to apply a lot of fertilizers when it is planted during the cultivation of wheat. What effect does fertilization have on wheat?
Effect of Nitrogen on Wheat
Nitrogen is the main factor affecting wheat quality. Within a certain range, the grain protein content increased with the increase of nitrogen application rate. The effect of nitrogen application time on the protein content of wheat grain was greater than the yield. Basically, the protein content gradually increased with the delay of the fertilization period. Both nitrogen topdressing time and method have a significant effect on the formation of wheat yield and quality. Under the same nitrogen application rate, postponing nitrogen application at the top-dressing stage and filling stage can enhance the ability of nitrogen metabolism and transformation in the later growth stage, and it is beneficial to increase wheat yield. Yield and improve nutritional quality and processing quality. Nitrogen application rate can significantly increase the content and output of dry and wet gluten, and with the delay of nitrogen application period, the dry and wet gluten content will gradually increase, which will have a good effect on increasing the content of dry and wet gluten. However, it is not always the case that the later the better, the most important factor is the application of nitrogen at flowering stage.
Effect of phosphorus on wheat
Maintaining a soil available phosphorus content of 22-30 mg/kg is very important for ensuring the high yield and quality of wheat. Phosphorus application had no adverse effect on nitrogen metabolism and grain protein. Phosphorus spraying has a good effect on the grain quality of wheat, but due to the excessive increase in yield due to phosphorus application, nitrogen is diluted in grains, which may reduce the protein content. In addition to being a nutrient that promotes the growth of crop roots, phosphorus plays an important role in enhancing wheat drought resistance. The combination of nitrogen and phosphorus has a greater effect on increasing wheat yield and improving quality, and is an important way to high yield and quality.
Effect of Potassium on Wheat
Potassium has a significant effect on wheat yield and quality. Potassium application can increase yield and improve quality. The use of potash fertilizer can improve the quality of wheat products. In the case of long-term application of organic fertilizer, the application of potash fertilizer can improve the processing quality of flour, but there must be sufficient supply of nitrogen and phosphorus to show good results, because potassium application promotes Absorption of nitrogen, if nitrogen is insufficient, does not function well as potassium. In short, balanced fertilization is a key measure for high yield, quality and efficiency of wheat.
The above is the introduction of the effect of fertilization on wheat. Friends who cultivate wheat can understand and apply fertilizers more rationally.
2018年4月3日星期二
2018年3月27日星期二
Application of Activated Carbon in Water Treatment
According to statistics, the annual industrial wastewater discharged from China is approximately 8×108m3, which contains not only highly toxic components such as cyanide but also metal ions such as chromium, zinc, and nickel. There are many waste water treatment methods, including chemical precipitation, electrolysis and membrane treatment. This article describes activated carbon adsorption. Activated carbon has a large surface area and high physical adsorption and chemical adsorption. Therefore, activated carbon adsorption is widely used in wastewater treatment. And it has high efficiency and good effect.
Activated carbon
Activated carbon is a special treatment of carbon, with numerous small pores, a large surface area, per gram of activated carbon surface area of 500-1500 square meters. Activated carbon has a strong physical adsorption and chemical adsorption function, but also has detoxification. Detoxification is the use of its huge area, the poison adsorbed in the pores of activated carbon, thus preventing the absorption of poisons. At the same time, activated carbon can be combined with a variety of chemicals to prevent the absorption of these substances.
Classification of activated carbon
There are many types of activated carbon used in production. Generally made into powder or granules.
Powdered activated carbon has a strong adsorption capacity, is easy to prepare, and has a low price, but it is difficult to regenerate and generally cannot be reused.
Granular activated carbon is more expensive, but it can be reused after being regenerated, and its working conditions are better when used, and its operation and management are convenient. Therefore, more granular activated carbon is used in water treatment [1].
Activated carbon adsorption
Activated carbon adsorption refers to the use of the solid surface of activated carbon to adsorb one or more substances in water to achieve the purpose of purifying water quality.
Activated carbon
Activated carbon is a special treatment of carbon, with numerous small pores, a large surface area, per gram of activated carbon surface area of 500-1500 square meters. Activated carbon has a strong physical adsorption and chemical adsorption function, but also has detoxification. Detoxification is the use of its huge area, the poison adsorbed in the pores of activated carbon, thus preventing the absorption of poisons. At the same time, activated carbon can be combined with a variety of chemicals to prevent the absorption of these substances.
Classification of activated carbon
There are many types of activated carbon used in production. Generally made into powder or granules.
Powdered activated carbon has a strong adsorption capacity, is easy to prepare, and has a low price, but it is difficult to regenerate and generally cannot be reused.
Granular activated carbon is more expensive, but it can be reused after being regenerated, and its working conditions are better when used, and its operation and management are convenient. Therefore, more granular activated carbon is used in water treatment [1].
Activated carbon adsorption
Activated carbon adsorption refers to the use of the solid surface of activated carbon to adsorb one or more substances in water to achieve the purpose of purifying water quality.
India prepares to revise the standard of vegetable oil
On March 21, 2018, the Indian Food Safety Standards Agency (FSSAI) issued a revised draft of the Food Safety and Standards (Food Standards and Food Additives) Regulations to amend the requirements for melting points and hydrogenated vegetable oils in mustard oil and palm oil; Formulated standards for five commodities such as palm stearin, palm kernel oil, and avocado oil. At the same time, it is planned to revise the requirements for peroxide values of all edible vegetable oils. Public comments are now open for comments.
How to control the Monochamus alternatus?
The Monochamus alternatus is an insect of the genus Monochamus of the genus Monochamus, an important pest of the Chinese pine tree, and also a devastating disease of pine trees. It is the major vector insect of the pine wood nematode disease, and it spreads and infects the pine wood nematode. In the process, it plays a key role in carrying, spreading, and assisting pathogens invading the host. Let's take a look at how to deal with it.
From October to April of the previous year (the pupa and adult stages)
1. Concentrate the damaged logs and pine rods, cover them with plastic film, place the fumigant evenly around the membrane, and quickly press the edges of the membrane with soil to seal it. Usually fumigation can take 2 to 3 days.
2. Steam heat, hot curing in chamber or heat treatment at constant temperature of 50°C for 24 hours. Pesticide wood fumigation and fumigation treatment must be performed before adult fly, aluminum phosphide 4g/m3, methyl bromide 16g/m3 Or sulfuryl fluoride.
3. Adjust the harvesting period to the end of autumn, and adjust the sales period to winter and spring so that all the pine rods under harvesting can be sold before the endangering of Tianniu, thus avoiding the occurrence of man-made insects.
In April and December, cleaning insect pest wood, weak wood, pressed wood and undergrowth shrubs, weeds, etc. can reduce the population density of pine brown beetle between forests.
5. The use of natural geographical conditions to open up a 4 km wide isolation zone can effectively prevent the spread of Monochamus alternatus.
6. Insect pests are stored outside the forest for 12 months after being felled. Newly cut pests are cut into planks with a thickness of 2 cm or less, which kills most of the brown monstrous cattle.
May to August (Yangfei adult stage)
1. Set bait traps and traps. The decoy wood is separated by more than 100 meters. Each point is cut 1 live pine tree, divided into 3 sections and stacked into a triangle frame. The branches are stacked under a tripod and a new section is added to the tripod at a certain interval. Tree sections.
2. The traps in the forest can be monitored for their occurrence and population changes. The impact of the hitting plate funnel or the hitting plate basin trap is best. The attractant is arranged in a 33 grid shape. 450-watt high-pressure mercury lamp was used to trap and kill Monochamus alternatus.
3. Spray 50% of acaricloside or 25% diflubenzuron III suspension 1000 to 1500 times, and use mid-April and mid-May use 50% 100% of buprofezin and buprofezin in mid-May. In the middle of June, spray twice 400 to 500 times Baosongling, in the middle and late June, ultra-low volume spray 8% green Weilai 900 ml/ha, and in the brown horn beetle nutritional period 12% fenthion EC 150 times +4 % polyvinyl alcohol 100 times + 2.5% deltamethrin EC 2000 times spray control.
May to September (eggs, larvae, and pupa)
In January and July, it was used to release the tuber swollen leg bee at a density of 0.5 million heads per hectare.
2, in the fall with a gauze bag of Beauveria bass powder or invasive hole injection of bacteria.
3, indoor breeding Huarong Ken Jia Lin release.
4, pay attention to protect tuber swollen leg bee, Beauveria bassiana and attract natural enemies such as woodpeckers.
5. Strictly strengthen quarantine and prohibit the transport of insect-infested wood and wooden packaging without any treatment. Once discovered, it will be destroyed on the spot.
From October to April of the previous year (the pupa and adult stages)
1. Concentrate the damaged logs and pine rods, cover them with plastic film, place the fumigant evenly around the membrane, and quickly press the edges of the membrane with soil to seal it. Usually fumigation can take 2 to 3 days.
2. Steam heat, hot curing in chamber or heat treatment at constant temperature of 50°C for 24 hours. Pesticide wood fumigation and fumigation treatment must be performed before adult fly, aluminum phosphide 4g/m3, methyl bromide 16g/m3 Or sulfuryl fluoride.
3. Adjust the harvesting period to the end of autumn, and adjust the sales period to winter and spring so that all the pine rods under harvesting can be sold before the endangering of Tianniu, thus avoiding the occurrence of man-made insects.
In April and December, cleaning insect pest wood, weak wood, pressed wood and undergrowth shrubs, weeds, etc. can reduce the population density of pine brown beetle between forests.
5. The use of natural geographical conditions to open up a 4 km wide isolation zone can effectively prevent the spread of Monochamus alternatus.
6. Insect pests are stored outside the forest for 12 months after being felled. Newly cut pests are cut into planks with a thickness of 2 cm or less, which kills most of the brown monstrous cattle.
May to August (Yangfei adult stage)
1. Set bait traps and traps. The decoy wood is separated by more than 100 meters. Each point is cut 1 live pine tree, divided into 3 sections and stacked into a triangle frame. The branches are stacked under a tripod and a new section is added to the tripod at a certain interval. Tree sections.
2. The traps in the forest can be monitored for their occurrence and population changes. The impact of the hitting plate funnel or the hitting plate basin trap is best. The attractant is arranged in a 33 grid shape. 450-watt high-pressure mercury lamp was used to trap and kill Monochamus alternatus.
3. Spray 50% of acaricloside or 25% diflubenzuron III suspension 1000 to 1500 times, and use mid-April and mid-May use 50% 100% of buprofezin and buprofezin in mid-May. In the middle of June, spray twice 400 to 500 times Baosongling, in the middle and late June, ultra-low volume spray 8% green Weilai 900 ml/ha, and in the brown horn beetle nutritional period 12% fenthion EC 150 times +4 % polyvinyl alcohol 100 times + 2.5% deltamethrin EC 2000 times spray control.
May to September (eggs, larvae, and pupa)
In January and July, it was used to release the tuber swollen leg bee at a density of 0.5 million heads per hectare.
2, in the fall with a gauze bag of Beauveria bass powder or invasive hole injection of bacteria.
3, indoor breeding Huarong Ken Jia Lin release.
4, pay attention to protect tuber swollen leg bee, Beauveria bassiana and attract natural enemies such as woodpeckers.
5. Strictly strengthen quarantine and prohibit the transport of insect-infested wood and wooden packaging without any treatment. Once discovered, it will be destroyed on the spot.
Fertilizer
At present, the strains used in bacterial fertilizers are generally medium-temperature microorganisms. When the soil temperature is between 25-37°C, it is most conducive to the growth and reproduction of bacteria. Once the soil temperature exceeds 37°C, the growth of bacteria will be obviously slowed or even stagnated. Fertilizer effects will also be affected. However, growth stagnation does not mean the death of the bacteria. When the temperature recovers normally and the soil moisture is around 50%, the bacteria will restore their growth and reproductive functions. If bacterial fertilizers are applied in high-temperature areas, it is recommended that companies select and isolate strains that are more resistant to high temperatures and add them to the fungicide to ensure the effectiveness of the bacteria.
In addition, heavy rainfall will also reduce the effect of bacterial fertilizer. The bacteria in most microbial strains are aerobic and require aerobic respiration. If the water in the soil is too long, it will affect the effect of bacterial fertilizer and must be drained in time. In addition, too much water will allow bacteria to be suspended in part of the water and washed away, thus affecting the bacterial fertilizer effect.
In addition, heavy rainfall will also reduce the effect of bacterial fertilizer. The bacteria in most microbial strains are aerobic and require aerobic respiration. If the water in the soil is too long, it will affect the effect of bacterial fertilizer and must be drained in time. In addition, too much water will allow bacteria to be suspended in part of the water and washed away, thus affecting the bacterial fertilizer effect.
How to judge "fat harm" is caused by quality problems?
Does the crop burn seedlings, burn roots, or is it not fertilizer or improper? After many “fat-harm” disputes occurred, dealers and farmers reported that some manufacturers often used “unsuitable use” to take responsibility for it. Farmers and distributors often could not get strong evidence and encountered such problems. do? Experts said that the detection of three factors can be:
One is to check whether the content of biuret in the fertilizer exceeds the standard, if the biuret is exceeded, it will cause burning of seedlings and burning of roots. The biuret is derived from urea. Quinified urea has a biuret content that meets the standard and does not produce “fat harm.” When the compound fertilizer nitrogen nutrient source is used for secondary processing, if the process is not performed properly at high temperatures, Biuret will be regenerated, resulting in "fatigue". In particular, there have been some new compound fertilizer granulation technologies, such as high-melt spray granulation, drum spray granulation, and other processes. If not properly controlled, biuret can easily be exceeded.
The second is that heavy metal pollution is also one of the important causes of plant burning seedlings and burning roots. At present, high-concentration compound fertilizers circulating on the market are less likely to be contaminated with heavy metals, while low-concentration compound fertilizers are more likely to be contaminated. However, in recent years, some manufacturers have added some trace elements in compound fertilizers to diversify marketing and manufacturing product selling points, which may lead to heavy metals. In addition, in high-concentration compound fertilizers, the use of unqualified and unqualified potassium fertilizers as raw materials may also cause excessive heavy metals. In order to respond to market competition, some compound fertilizer companies may also add hidden components to products so that they can achieve better results and market feedback. These recessive components may have positive effects in some soils. In other circumstances it is likely to cause "fat harm."
The third is to detect whether the chloride ion exceeds the standard. On the one hand, chlorine-free crops that use chlorine-containing fertilizer will undoubtedly produce “fat harm”; on the other hand, even if it is not a chlorine-tolerant crop, if the chloride ion concentration is too high, it will also cause salt damage. , causing burning seedlings, burning roots and other issues. The "fat harm" caused by excessive chloride ion is closely related to soil and climate. If the weather is dry and the soil moisture is low, a large amount of chemical fertilizers will easily cause salt damage when applied to the soil, especially for the double chlorine type compound fertilizer (referring to compound Fertilizer raw materials come from ammonium chloride and potassium chloride. This problem is particularly acute. At present, such damage is more frequent in arid regions north of the Huaihe River.
One is to check whether the content of biuret in the fertilizer exceeds the standard, if the biuret is exceeded, it will cause burning of seedlings and burning of roots. The biuret is derived from urea. Quinified urea has a biuret content that meets the standard and does not produce “fat harm.” When the compound fertilizer nitrogen nutrient source is used for secondary processing, if the process is not performed properly at high temperatures, Biuret will be regenerated, resulting in "fatigue". In particular, there have been some new compound fertilizer granulation technologies, such as high-melt spray granulation, drum spray granulation, and other processes. If not properly controlled, biuret can easily be exceeded.
The second is that heavy metal pollution is also one of the important causes of plant burning seedlings and burning roots. At present, high-concentration compound fertilizers circulating on the market are less likely to be contaminated with heavy metals, while low-concentration compound fertilizers are more likely to be contaminated. However, in recent years, some manufacturers have added some trace elements in compound fertilizers to diversify marketing and manufacturing product selling points, which may lead to heavy metals. In addition, in high-concentration compound fertilizers, the use of unqualified and unqualified potassium fertilizers as raw materials may also cause excessive heavy metals. In order to respond to market competition, some compound fertilizer companies may also add hidden components to products so that they can achieve better results and market feedback. These recessive components may have positive effects in some soils. In other circumstances it is likely to cause "fat harm."
The third is to detect whether the chloride ion exceeds the standard. On the one hand, chlorine-free crops that use chlorine-containing fertilizer will undoubtedly produce “fat harm”; on the other hand, even if it is not a chlorine-tolerant crop, if the chloride ion concentration is too high, it will also cause salt damage. , causing burning seedlings, burning roots and other issues. The "fat harm" caused by excessive chloride ion is closely related to soil and climate. If the weather is dry and the soil moisture is low, a large amount of chemical fertilizers will easily cause salt damage when applied to the soil, especially for the double chlorine type compound fertilizer (referring to compound Fertilizer raw materials come from ammonium chloride and potassium chloride. This problem is particularly acute. At present, such damage is more frequent in arid regions north of the Huaihe River.
5 commonly used top dressing methods
Crops need to be topdressed after sowing and planting. The amount of topdressing usually accounts for about 1/3 or more of the total amount of fertilizer applied during the whole growing period of the crop. Now introduce several commonly used top dressing methods, enumerate its advantages and disadvantages, for the majority of farmers friends reference.
Direct applicator
When the crop is watered or after it has rained, it is suitable for the field and the fertiliser can be applied directly to the crop lines. Although this method is relatively simple, part of the fertilizer will volatilize and lose, especially ammonium bicarbonate is very volatile and can not be used; ammonium sulfate, urea and potassium sulfate can be applied, but it is only inconvenient in the field, crops need to Fertilizer and more urgent case selection.
With water pouring
When the crop is watered, the fertilizer is applied with water to the soil surrounding the roots of the crop. The drawback of this method is that it is more wasteful, easily lost, and does not reach the deep layers of the crop root; the advantage is that it is simple to use, saves time and labor, and labor is not large. It can be used when the source of fertilizer is sufficient, the area for planting is large, and labor conflicts are prominent. When a large area of crops appears severely infertility, it can be used as the top dressing method.
Deep fertilization
Grows digging pits between plant lines and rows, applies fertilizers, and covers the soil. Using this method, fertilizer is less wasteful and most economical, but it has a large amount of labor and is labor-intensive, and the operation is not very convenient. When applying, pay attention to the buried trenches and pits that are more than 10cm away from the base of the roots and stems of the crops. If the roots are too close to the roots, the roots may be easily damaged. Due to the concentration of fertilizers and their high concentration, this method should not be used in summer when crops grow vigorously and require more water, and it cannot be used during critical periods of crop water demand. Usually in the winter season, when the labor force is sufficient and the crop growth is not large, this method can be used to gradually decompose the fertilizer buried in the soil and continuously supply the crop. However, in actual production, the peak of crop growth is often the peak of demand fertilizer and water, therefore, the buried method is often used when the temperature is high. In order to prevent it from having a negative effect, it is necessary to water after burial, so that the concentration of fertilizers buried in the plant can be reduced.
Facilities
In recent years, drip irrigation technology has been widely used, and the automation of fertilization has gradually become popular. The specific method of using the drip irrigation facility for top dressing is to install a fertilizing device at the place where the water source enters the drip irrigation pipe, dissolve the fertilizer in the fertilizing device, insert the drip irrigation pipe into the suction pipe filter of the fertilizer, and the fertilizer can automatically enter the crop root with watering. In the surrounding soil. The advantage is that due to the cover of the plastic film, the fertilizer hardly volatilizes, no loss occurs, and the fertilizer is concentrated, but the concentration is small, so it is safe, labor-saving, and effective. This is a top-dressing method that is currently relatively scientific and has great prospects for development. However, due to the large investment, it is difficult to promote it in large-scale production.
Root dressing
Outside the top dressing is foliar spray fertilizer. In the cultivation of facilities, the artificially created environment is more conducive to meeting the requirements of the crops on environmental conditions, and the crops show the characteristics of rapid growth, high yield, and large results. Spraying is often used in production to make foliar dressings to supplement crop nutrient deficiencies. The method has the advantages of less dosage and quicker fertilizer effect, and can prevent the active ingredients in the fertilizer from being fixed by the soil, and is an economic and effective fertilizer application method.
In the case of obvious lack of nutrient elements and root senescence in the later stage of crop growth, it can better show its effect. In addition to the large amount of elemental fertilizers commonly used in urea, potassium dihydrogen phosphate, potassium sulfate, potassium nitrate, and compound fertilizers, fertilizers for dressing fertilizers from the roots have been developed by many manufacturers in recent years. Add trace elements or fertilizers containing various amino acids. However, it must be explained that the basic nutrients needed for the growth and development of crops mainly come from basal fertilizers and fertilizers that are applied in other ways. Extra-root fertilizers can only be used as an auxiliary measure.
Direct applicator
When the crop is watered or after it has rained, it is suitable for the field and the fertiliser can be applied directly to the crop lines. Although this method is relatively simple, part of the fertilizer will volatilize and lose, especially ammonium bicarbonate is very volatile and can not be used; ammonium sulfate, urea and potassium sulfate can be applied, but it is only inconvenient in the field, crops need to Fertilizer and more urgent case selection.
With water pouring
When the crop is watered, the fertilizer is applied with water to the soil surrounding the roots of the crop. The drawback of this method is that it is more wasteful, easily lost, and does not reach the deep layers of the crop root; the advantage is that it is simple to use, saves time and labor, and labor is not large. It can be used when the source of fertilizer is sufficient, the area for planting is large, and labor conflicts are prominent. When a large area of crops appears severely infertility, it can be used as the top dressing method.
Deep fertilization
Grows digging pits between plant lines and rows, applies fertilizers, and covers the soil. Using this method, fertilizer is less wasteful and most economical, but it has a large amount of labor and is labor-intensive, and the operation is not very convenient. When applying, pay attention to the buried trenches and pits that are more than 10cm away from the base of the roots and stems of the crops. If the roots are too close to the roots, the roots may be easily damaged. Due to the concentration of fertilizers and their high concentration, this method should not be used in summer when crops grow vigorously and require more water, and it cannot be used during critical periods of crop water demand. Usually in the winter season, when the labor force is sufficient and the crop growth is not large, this method can be used to gradually decompose the fertilizer buried in the soil and continuously supply the crop. However, in actual production, the peak of crop growth is often the peak of demand fertilizer and water, therefore, the buried method is often used when the temperature is high. In order to prevent it from having a negative effect, it is necessary to water after burial, so that the concentration of fertilizers buried in the plant can be reduced.
Facilities
In recent years, drip irrigation technology has been widely used, and the automation of fertilization has gradually become popular. The specific method of using the drip irrigation facility for top dressing is to install a fertilizing device at the place where the water source enters the drip irrigation pipe, dissolve the fertilizer in the fertilizing device, insert the drip irrigation pipe into the suction pipe filter of the fertilizer, and the fertilizer can automatically enter the crop root with watering. In the surrounding soil. The advantage is that due to the cover of the plastic film, the fertilizer hardly volatilizes, no loss occurs, and the fertilizer is concentrated, but the concentration is small, so it is safe, labor-saving, and effective. This is a top-dressing method that is currently relatively scientific and has great prospects for development. However, due to the large investment, it is difficult to promote it in large-scale production.
Root dressing
Outside the top dressing is foliar spray fertilizer. In the cultivation of facilities, the artificially created environment is more conducive to meeting the requirements of the crops on environmental conditions, and the crops show the characteristics of rapid growth, high yield, and large results. Spraying is often used in production to make foliar dressings to supplement crop nutrient deficiencies. The method has the advantages of less dosage and quicker fertilizer effect, and can prevent the active ingredients in the fertilizer from being fixed by the soil, and is an economic and effective fertilizer application method.
In the case of obvious lack of nutrient elements and root senescence in the later stage of crop growth, it can better show its effect. In addition to the large amount of elemental fertilizers commonly used in urea, potassium dihydrogen phosphate, potassium sulfate, potassium nitrate, and compound fertilizers, fertilizers for dressing fertilizers from the roots have been developed by many manufacturers in recent years. Add trace elements or fertilizers containing various amino acids. However, it must be explained that the basic nutrients needed for the growth and development of crops mainly come from basal fertilizers and fertilizers that are applied in other ways. Extra-root fertilizers can only be used as an auxiliary measure.
2018年3月23日星期五
What are the food additives? Need to use it rationally
Recently, Guangdong issued the "Notice on Further Strengthening School Food Safety and Promoting Dietary and Nutritional Equilibrium Work" to guide school canteens to arrange meals properly. Pickled foods such as skewers and ham will not be regarded as leeks, and schools will gradually not sell health-impaired foods. Carbonated drinks, instant noodles, etc. It is understood that most of these mentioned foods contain food additives, and eating too much will not benefit the human body.
What is a food additive?
Food additives is a proper term, which specifically refers to those countries that permit the use of substances added to foods. Formaldehyde, Sudan Red, and melamine, toxic and hazardous substances, are called non-edible substances. Non-food substances are used in foods. How much is added is illegal. Food additives are different, as long as they are not used in excess or in excess, they are legal. For example, adding a nationally-approved food color to candy can be illegal if it does not exceed the standard. Unless scientific research finds that it has a new toxic response, it is only for the government department to change its use limit or remove it from the list of food additives.
Tips: Food additives and non-food substances are not a concept. Food additives are not harmful to human health as long as they are added in amounts specified by the state, but they are not good for health, especially for children. A large number of food additive snacks can easily destroy children's taste and cause a series of health problems.
For food additives, consumers do not need to panic, but they cannot be condoned. Therefore, consumers should correct their own consumer attitudes, treat food additives with an objective and fair attitude, and at the same time do not give up on the questioning and supervision of food safety.
What is a food additive?
Food additives is a proper term, which specifically refers to those countries that permit the use of substances added to foods. Formaldehyde, Sudan Red, and melamine, toxic and hazardous substances, are called non-edible substances. Non-food substances are used in foods. How much is added is illegal. Food additives are different, as long as they are not used in excess or in excess, they are legal. For example, adding a nationally-approved food color to candy can be illegal if it does not exceed the standard. Unless scientific research finds that it has a new toxic response, it is only for the government department to change its use limit or remove it from the list of food additives.
Tips: Food additives and non-food substances are not a concept. Food additives are not harmful to human health as long as they are added in amounts specified by the state, but they are not good for health, especially for children. A large number of food additive snacks can easily destroy children's taste and cause a series of health problems.
For food additives, consumers do not need to panic, but they cannot be condoned. Therefore, consumers should correct their own consumer attitudes, treat food additives with an objective and fair attitude, and at the same time do not give up on the questioning and supervision of food safety.
Application of Activated Carbon in Water Treatment
According to statistics, the annual industrial wastewater discharged from China is approximately 8×108m3, which contains not only highly toxic components such as cyanide but also metal ions such as chromium, zinc, and nickel. There are many waste water treatment methods, including chemical precipitation, electrolysis and membrane treatment. This article describes activated carbon adsorption. Activated carbon has a large surface area and high physical adsorption and chemical adsorption. Therefore, activated carbon adsorption is widely used in wastewater treatment. And it has high efficiency and good effect.
Activated carbon
Activated carbon is a special treatment of carbon, with numerous small pores, a large surface area, per gram of activated carbon surface area of 500-1500 square meters. Activated carbon has a strong physical adsorption and chemical adsorption function, but also has detoxification. Detoxification is the use of its huge area, the poison adsorbed in the pores of activated carbon, thus preventing the absorption of poisons. At the same time, activated carbon can be combined with a variety of chemicals to prevent the absorption of these substances.
Classification of activated carbon
There are many types of activated carbon used in production. Generally made into powder or granules.
Powdered activated carbon has a strong adsorption capacity, is easy to prepare, and has a low price, but it is difficult to regenerate, and generally cannot be reused.
Granular activated carbon is more expensive, but it can be reused after being regenerated, and its working conditions are better when used, and its operation and management are convenient. Therefore, more granular activated carbon is used in water treatment [1].
Activated carbon adsorption
Activated carbon adsorption refers to the use of the solid surface of activated carbon to adsorb one or more substances in water to achieve the purpose of purifying water quality.
Factors Affecting Activated Carbon Adsorption
Adsorption capacity and adsorption rate are the main indicators to measure the adsorption process. The size of adsorption capacity is measured by the amount of adsorption. The adsorption rate refers to the amount of substance adsorbed per unit weight per unit time. In water treatment, the adsorption rate determines the contact time between the wastewater and the adsorbent.
The adsorption capacity of activated carbon is related to pore size and structure of activated carbon. In general, the smaller the particles, the faster the pore diffusion rate and the stronger the adsorption capacity of activated carbon.
The pH and temperature of the sewage also have an effect on the adsorption of activated carbon. Activated carbon generally has a higher adsorption capacity under acidic conditions than under alkaline conditions. The adsorption reaction is usually an exothermic reaction, so a low temperature favors the adsorption reaction.
Of course, the adsorption capacity of activated carbon is related to the concentration of sewage. At a certain temperature, the adsorption capacity of activated carbon increases with the increase of the equilibrium concentration of the adsorbed material.
Application of Activated Carbon in Sewage Treatment
Because activated carbon requires high pretreatment of water, and the price of activated carbon is expensive, activated carbon is mainly used to remove trace contaminants from wastewater in the treatment of wastewater for the purpose of deep purification.
Activated carbon treatment of chromium-containing wastewater
Chromium is a kind of metal raw material with a relatively large amount in electroplating. In the waste water, hexavalent chromium exists in different forms with different pH values.
Activated carbon has a well-developed microporous structure and a high specific surface area, has a strong physical adsorption capacity, and can effectively adsorb Cr(VI) in wastewater. On the surface of activated carbon, there are a large number of oxygen-containing groups such as hydroxyl (-OH), carboxyl (-COOH), etc. They all have electrostatic adsorption function and produce chemical adsorption of Cr(VI). It can be completely used to treat Cr(VI) in electroplating wastewater. The wastewater after adsorption can meet the national emission standards.
The results showed that the Cr(VI) concentration in the solution was 50 mg/L, the pH was 3, and the adsorption time was 1.5 h. The adsorption performance of activated carbon and the removal rate of Cr(VI) all reached the best effect.
The
Therefore, the process of using activated carbon to treat chromium-containing wastewater is the result of comprehensive effects of physical adsorption, chemical adsorption and chemical reduction of activated carbon on Cr(VI) in solution. The activated carbon treatment of chromium-containing wastewater has stable adsorption performance, high treatment efficiency, low operating costs, and certain social and economic benefits.
Activated carbon
Activated carbon is a special treatment of carbon, with numerous small pores, a large surface area, per gram of activated carbon surface area of 500-1500 square meters. Activated carbon has a strong physical adsorption and chemical adsorption function, but also has detoxification. Detoxification is the use of its huge area, the poison adsorbed in the pores of activated carbon, thus preventing the absorption of poisons. At the same time, activated carbon can be combined with a variety of chemicals to prevent the absorption of these substances.
Classification of activated carbon
There are many types of activated carbon used in production. Generally made into powder or granules.
Powdered activated carbon has a strong adsorption capacity, is easy to prepare, and has a low price, but it is difficult to regenerate, and generally cannot be reused.
Granular activated carbon is more expensive, but it can be reused after being regenerated, and its working conditions are better when used, and its operation and management are convenient. Therefore, more granular activated carbon is used in water treatment [1].
Activated carbon adsorption
Activated carbon adsorption refers to the use of the solid surface of activated carbon to adsorb one or more substances in water to achieve the purpose of purifying water quality.
Factors Affecting Activated Carbon Adsorption
Adsorption capacity and adsorption rate are the main indicators to measure the adsorption process. The size of adsorption capacity is measured by the amount of adsorption. The adsorption rate refers to the amount of substance adsorbed per unit weight per unit time. In water treatment, the adsorption rate determines the contact time between the wastewater and the adsorbent.
The adsorption capacity of activated carbon is related to pore size and structure of activated carbon. In general, the smaller the particles, the faster the pore diffusion rate and the stronger the adsorption capacity of activated carbon.
The pH and temperature of the sewage also have an effect on the adsorption of activated carbon. Activated carbon generally has a higher adsorption capacity under acidic conditions than under alkaline conditions. The adsorption reaction is usually an exothermic reaction, so a low temperature favors the adsorption reaction.
Of course, the adsorption capacity of activated carbon is related to the concentration of sewage. At a certain temperature, the adsorption capacity of activated carbon increases with the increase of the equilibrium concentration of the adsorbed material.
Application of Activated Carbon in Sewage Treatment
Because activated carbon requires high pretreatment of water, and the price of activated carbon is expensive, activated carbon is mainly used to remove trace contaminants from wastewater in the treatment of wastewater for the purpose of deep purification.
Activated carbon treatment of chromium-containing wastewater
Chromium is a kind of metal raw material with a relatively large amount in electroplating. In the waste water, hexavalent chromium exists in different forms with different pH values.
Activated carbon has a well-developed microporous structure and a high specific surface area, has a strong physical adsorption capacity, and can effectively adsorb Cr(VI) in wastewater. On the surface of activated carbon, there are a large number of oxygen-containing groups such as hydroxyl (-OH), carboxyl (-COOH), etc. They all have electrostatic adsorption function and produce chemical adsorption of Cr(VI). It can be completely used to treat Cr(VI) in electroplating wastewater. The wastewater after adsorption can meet the national emission standards.
The results showed that the Cr(VI) concentration in the solution was 50 mg/L, the pH was 3, and the adsorption time was 1.5 h. The adsorption performance of activated carbon and the removal rate of Cr(VI) all reached the best effect.
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Therefore, the process of using activated carbon to treat chromium-containing wastewater is the result of comprehensive effects of physical adsorption, chemical adsorption and chemical reduction of activated carbon on Cr(VI) in solution. The activated carbon treatment of chromium-containing wastewater has stable adsorption performance, high treatment efficiency, low operating costs, and certain social and economic benefits.
Guidelines for the use of pesticides commonly used in vegetables
When pests and diseases are controlled by vegetable farmers, they always do not pay attention to the interval between the use of vegetables before they are put on the market, so that pesticide residues are excessive. Xiao Bian now introduces the reasonable use standards of pesticides commonly used in vegetables on the Ministry of Agriculture's pesticide inspections as follows:
Acaricides
1, 50% Bromoxime EC is separated by 14 days.
2, 50% Torc WP pesticide safety interval of 7 days.
Fungicides
1, 75% chlorothalonil wettable powder is used 7 days before marketing.
2,77% can kill WP for 3-5 days.
3, 50% acetaminophen wettable powder 4-7 days.
4, 70% thiophanate-methyl wettable powder 5-7 days.
5, 50% nareli wettable powder 4-5 days.
6, 50% Garrett 58% Rexroth Manganese Zinc Wettable Powder 2-3 days
7, 64% anti-virus WP can be 3 to 4 days.
Insecticide
1. 10% cypermethrin EC for 2-5 days.
2. 2.5% bifenthrin for 2 days.
3, 2.5% Kung Fu EC for 7 days.
4.5% linacin EC for 3 days.
5,5% anti-inflamy WP for 6 days
6. 1.8% of AIFU's EC.
7, 10% kill the enemy EC for 3 days.
8,40.7% Lost cream for 7 days.
9, 20% chlorhexidine EC for 3 days.
10, 20% fenvalerate EC safe interval of 5 days.
11, 35% of superior anti-virus phosphorus period of 7 days.
12. 20% of fenpropathrin EC has a safety interval of 3 days.
13, 10% Mapilico EC interval of 7 days.
14, quizulfuron 25% EC interval of 9 days.
15, 50% anti-inferiority WP safety interval of 6 days.
16, 5% Dolebo WP can be used for 7 days.
Acaricides
1, 50% Bromoxime EC is separated by 14 days.
2, 50% Torc WP pesticide safety interval of 7 days.
Fungicides
1, 75% chlorothalonil wettable powder is used 7 days before marketing.
2,77% can kill WP for 3-5 days.
3, 50% acetaminophen wettable powder 4-7 days.
4, 70% thiophanate-methyl wettable powder 5-7 days.
5, 50% nareli wettable powder 4-5 days.
6, 50% Garrett 58% Rexroth Manganese Zinc Wettable Powder 2-3 days
7, 64% anti-virus WP can be 3 to 4 days.
Insecticide
1. 10% cypermethrin EC for 2-5 days.
2. 2.5% bifenthrin for 2 days.
3, 2.5% Kung Fu EC for 7 days.
4.5% linacin EC for 3 days.
5,5% anti-inflamy WP for 6 days
6. 1.8% of AIFU's EC.
7, 10% kill the enemy EC for 3 days.
8,40.7% Lost cream for 7 days.
9, 20% chlorhexidine EC for 3 days.
10, 20% fenvalerate EC safe interval of 5 days.
11, 35% of superior anti-virus phosphorus period of 7 days.
12. 20% of fenpropathrin EC has a safety interval of 3 days.
13, 10% Mapilico EC interval of 7 days.
14, quizulfuron 25% EC interval of 9 days.
15, 50% anti-inferiority WP safety interval of 6 days.
16, 5% Dolebo WP can be used for 7 days.
Improper fertilization to aggravate diseases and greenhouse diseases
At present, many vegetable greenhouses cause burned seedlings and increased disease due to improper fertilization. According to the expert's typical experience of scientific fertilization of greenhouse vegetables, greenhouse vegetable cultivation should pay attention to five points in fertilization:
Greenhouse vegetable fertilization
First, the appropriate amount of fertilizer
Because greenhouses have protective facilities, the soil cannot be fully washed by rainwater, and fertilizers are not easily lost. Therefore, excessive application of chemical fertilizers can easily cause salt to accumulate on the surface of the soil, lightly affect the growth of vegetables, and cause soil salinization. Therefore, before fertilizing, soil nutrients must be diagnosed, a rational formula fertilization plan should be formulated, and the quick-effect fertilizer should be applied in excess to prevent blindness.
Second, pay attention to potassium fertilizer:
The application of potash fertilizer in melons and solanaceous vegetables has obvious effect on yield increase. This is due to the partial application of nitrogen and phosphorus fertilizers in greenhouses with greenhouse vegetables. As a result, the soil potassium supply decreases with the increase of planting years and the increase of vegetable yield. According to the experiment, cucumbers in the greenhouses and 7.5 kg of potassium oxide were applied to the sheds, showing that the stems are thick, the leaves are bright green and thick, and the melon strips are straight. In winter, the Chinese cabbage has an obvious increase in yield and quality. It should be noted that when using potash fertilizers, it is best not to use potassium chloride to avoid soil salinization.
Third, a small amount of fertilizer:
Vegetables need more fertilizer, in addition to the application of full-body fertilizer, but also need topdressing, top dressing, it should be a small number of times, so that can prevent the loss of nutrients, and can give full play to fertilizer efficiency, improve fertilizer utilization.
Fourth, the lack of nutrient supplements:
Although the demand for microelements in vegetables is small, micronutrients are indispensable nutrients involved in the physiological effects of vegetables. For example, if the trace elements in the soil are insufficient, the vegetables will have different symptoms of deficiency, and the yield will decrease and the quality will decline. If the content of trace elements in the soil is too much, it will cause vegetable poisoning, which also causes a decrease in production and quality. Therefore, the application of trace element fertilizer must be based on soil test results and the lack of vegetables, and must be based on the principle of lack of fill.
Fifth, the top-dressing fertilizer should be accurate:
Foliar spray fertilizer method is simple, save time and labor, can avoid excessive water caused by excessive soil moisture resulting in increased disease susceptibility of vegetables, but also quickly add nutrients, but to grasp the application concentration, otherwise easy to produce fertilizer damage, “ Burning leaves, generally foliar spraying fertilizer concentration: urea 1%, potassium dihydrogen phosphate 0.2~0.5%, diammonium phosphate 1%, zinc sulfate 0.1~0.2%, manganese sulfate 0.1~0.2%, borax 0.1~0.2% Ammonium molybdate 0.05 to 0.1%, copper sulfate 0.02 to 0.2%, and ferrous sulfate 0.2 to 1%.
Greenhouse vegetable fertilization
First, the appropriate amount of fertilizer
Because greenhouses have protective facilities, the soil cannot be fully washed by rainwater, and fertilizers are not easily lost. Therefore, excessive application of chemical fertilizers can easily cause salt to accumulate on the surface of the soil, lightly affect the growth of vegetables, and cause soil salinization. Therefore, before fertilizing, soil nutrients must be diagnosed, a rational formula fertilization plan should be formulated, and the quick-effect fertilizer should be applied in excess to prevent blindness.
Second, pay attention to potassium fertilizer:
The application of potash fertilizer in melons and solanaceous vegetables has obvious effect on yield increase. This is due to the partial application of nitrogen and phosphorus fertilizers in greenhouses with greenhouse vegetables. As a result, the soil potassium supply decreases with the increase of planting years and the increase of vegetable yield. According to the experiment, cucumbers in the greenhouses and 7.5 kg of potassium oxide were applied to the sheds, showing that the stems are thick, the leaves are bright green and thick, and the melon strips are straight. In winter, the Chinese cabbage has an obvious increase in yield and quality. It should be noted that when using potash fertilizers, it is best not to use potassium chloride to avoid soil salinization.
Third, a small amount of fertilizer:
Vegetables need more fertilizer, in addition to the application of full-body fertilizer, but also need topdressing, top dressing, it should be a small number of times, so that can prevent the loss of nutrients, and can give full play to fertilizer efficiency, improve fertilizer utilization.
Fourth, the lack of nutrient supplements:
Although the demand for microelements in vegetables is small, micronutrients are indispensable nutrients involved in the physiological effects of vegetables. For example, if the trace elements in the soil are insufficient, the vegetables will have different symptoms of deficiency, and the yield will decrease and the quality will decline. If the content of trace elements in the soil is too much, it will cause vegetable poisoning, which also causes a decrease in production and quality. Therefore, the application of trace element fertilizer must be based on soil test results and the lack of vegetables, and must be based on the principle of lack of fill.
Fifth, the top-dressing fertilizer should be accurate:
Foliar spray fertilizer method is simple, save time and labor, can avoid excessive water caused by excessive soil moisture resulting in increased disease susceptibility of vegetables, but also quickly add nutrients, but to grasp the application concentration, otherwise easy to produce fertilizer damage, “ Burning leaves, generally foliar spraying fertilizer concentration: urea 1%, potassium dihydrogen phosphate 0.2~0.5%, diammonium phosphate 1%, zinc sulfate 0.1~0.2%, manganese sulfate 0.1~0.2%, borax 0.1~0.2% Ammonium molybdate 0.05 to 0.1%, copper sulfate 0.02 to 0.2%, and ferrous sulfate 0.2 to 1%.
Eggplant temperature management skills! From heat preservation, increased light, moisture control
During the cultivation of the eggplant in the greenhouse, the management of temperature is an important step. The specific measures taken are as follows:
1. Strengthen the indoor temperature management.
Before flowering results, keep the temperature as high as possible at 15~20°C to promote flower buds to form more flower styles and increase seed setting rate. After the flowering results, it is necessary to pay attention to raising the temperature inside the shed, with particular attention to the ground temperature. It is best to keep it above 20°C and keep it at a minimum of 15°C. The management of the noon temperature can be increased by 2~3°C to ensure that the night temperature is appropriate. After watering, in order to maintain the ground temperature, it is necessary to raise the temperature of the greenhouse in a timely manner, and keep the air in the greenhouse dry to reduce the incidence of eggplant.
2. Strengthen the management of fertilizer and water in different growth periods of eggplant.
Because the eggplant needs less water in the early stage, watering is basically unnecessary. However, it is still necessary to use the fertilizer (organic humic acid liquid fertilizer) to root. In the result period, the amount of water needed was large, and the number of times of watering should be appropriately increased. The lack of water would cause small fruit, and the surface of solanaceous fruit on the base stem had no luster, affecting the yield and quality of eggplant.
3. The eggplant flowering period must take full advantage of light and temperature conditions.
Keep the temperature in the shed and the ground temperature stable, remove old leaves and side branches in time, and often clean the shed, keep it clean and light, promote fruit growth and coloration, and timely harvest and sell.
4. From the time of planting to easing seedlings and fruit set, scientific management of fertilizer and water should be done.
Grasp the principle of "small fertilizers to raise roots, fertilizers to promote seedlings, big fertilizers to raise fruit". In the growth stage of strong seedlings, the amount of fertilizer to be poured should not be too large. Therefore, biofungus fertilizer should be selected for flushing and the method of inter-irrigation should be adopted.
The management of temperature is crucial to increase the yield of eggplant. According to the characteristics of winter, we should strengthen management from the aspects of heat preservation, light increase, humidity control and disease prevention.
1. Strengthen the indoor temperature management.
Before flowering results, keep the temperature as high as possible at 15~20°C to promote flower buds to form more flower styles and increase seed setting rate. After the flowering results, it is necessary to pay attention to raising the temperature inside the shed, with particular attention to the ground temperature. It is best to keep it above 20°C and keep it at a minimum of 15°C. The management of the noon temperature can be increased by 2~3°C to ensure that the night temperature is appropriate. After watering, in order to maintain the ground temperature, it is necessary to raise the temperature of the greenhouse in a timely manner, and keep the air in the greenhouse dry to reduce the incidence of eggplant.
2. Strengthen the management of fertilizer and water in different growth periods of eggplant.
Because the eggplant needs less water in the early stage, watering is basically unnecessary. However, it is still necessary to use the fertilizer (organic humic acid liquid fertilizer) to root. In the result period, the amount of water needed was large, and the number of times of watering should be appropriately increased. The lack of water would cause small fruit, and the surface of solanaceous fruit on the base stem had no luster, affecting the yield and quality of eggplant.
3. The eggplant flowering period must take full advantage of light and temperature conditions.
Keep the temperature in the shed and the ground temperature stable, remove old leaves and side branches in time, and often clean the shed, keep it clean and light, promote fruit growth and coloration, and timely harvest and sell.
4. From the time of planting to easing seedlings and fruit set, scientific management of fertilizer and water should be done.
Grasp the principle of "small fertilizers to raise roots, fertilizers to promote seedlings, big fertilizers to raise fruit". In the growth stage of strong seedlings, the amount of fertilizer to be poured should not be too large. Therefore, biofungus fertilizer should be selected for flushing and the method of inter-irrigation should be adopted.
The management of temperature is crucial to increase the yield of eggplant. According to the characteristics of winter, we should strengthen management from the aspects of heat preservation, light increase, humidity control and disease prevention.
Healthy soil is the key to improving the quality of vegetables!
Soil is one of the main factors for the high yield of vegetables. However, in recent years, with the increase of soil-borne diseases, the death of dead trees, and the aggravation of the phenomenon, it has caused great losses to vegetable farmers. The quality of soil is also an important factor affecting the development of vegetable root systems. the reason. Therefore, the soil is the key to the high yield of vegetables!
What kind of soil do the vegetables need?
Vegetables generally grow faster and can be harvested many times during the planting process. Therefore, the roots have stronger absorption capacity and require more calcium and boron. Therefore, they have higher soil requirements.
1. Soil highly matured
The content of organic matter is required to reach 2% to 3%, preferably 3% to 4%. The total porosity is about 60%. The depth of groundwater is less than 2.5 meters and the best soil is loamy soil.
2. Good farming
The suitable soil bulk density for vegetables is 1.1-1.3 g/cm3, and the soil hardness after cultivating the vegetable garden is preferably 20-30 kg/cm2, and more than 30 kg/cm2 will have an adverse effect on the root system.
3 good temperature and humidity
The soil temperature stability is closely related to the specific heat and heat conductivity of the soil. The humified loam has the highest specific heat, and the clay soil and organic-rich soils have moderate heat capacity and good temperature stability.
4. Contains higher nutrient content
Requires total nitrogen content of 0.1% or more, alkaline hydrolysis nitrogen 75 mg/kg or more, available potassium 150 mg/kg or more, available phosphorus 30 mg/kg or more, magnesium oxide 150 to 240 mg/kg, calcium oxide 0.1% to 0.14%, At the same time contains a certain amount of boron, manganese, zinc, copper, iron, molybdenum and other trace elements. The soil salt content does not exceed 0.4%, with slightly acidic.
5. Strong water storage and oxygen supply capacity
When the maximum water holding capacity is reached in the field, it is required that the soil can maintain oxygen content of more than 15%.
The effect of soil problems on vegetables
1. Soil organic matter is lacking and yield is declining
Soil compaction, a serious lack of organic matter, mainly due to the large number of application of chemical fertilizers, the annual neglect of the application of organic fertilizer, resulting in poor soil permeability, microbial reduction, poor root development will be vulnerable to disease. For many years, continuous cropping leads to insufficient trace elements in soil and aggravated salinization seriously affects the growth of vegetables.
2. The plough layer becomes shallow, affecting the development of the root system
The soil plough layer is shallow, and the vegetable field is mostly digging by hand. The intercropping and interplanting of the cultivars is less. The soil layer is gradually shallow and the root extension is affected.
3. Increase in pests and other harmful substances
Deterioration of the soil will also lead to an increase in pests and diseases. In the process of growing vegetables, due to unreasonable fertilization and pesticide application, the problem of soil pollution will become increasingly serious and cause food safety incidents.
Improvement measures
1. Increase organic fertilizer
After organic manure is applied, the organic matter in the soil is replenished, water, fertilizer, and gas are coordinated and developed, and a good growth environment is created for the growth of the vegetables, ensuring the growth of roots, stems and leaves.
2. Deep plowing soil
In combination with organic fertilizers, the soil is deeply ploughed to increase the permeability of the soil and promote soil ripening. It can also increase the effectiveness of organic fertilizers. After the general vegetable is planted, it should be scratched once every 3-5 days, and the depth should be 3 cm.
3. Rational rotation
To rotate vegetables properly, such as deep-rooted legumes, melons, and solanaceous fruit, with shallow-rooted Chinese cabbage, cabbage, cucumber, onion and garlic, etc. to make full use of different soil nutrients to improve soil fertility. Reduce bacterial accumulation.
4. Increase soil microbial content
After a long period of continuous cropping, vegetables have accumulated a large amount of harmful substances, and beneficial microorganisms have gradually decreased. It is possible to improve soil compaction, release nutrients, and promote crop root growth by applying microbial fertilizer.
What kind of soil do the vegetables need?
Vegetables generally grow faster and can be harvested many times during the planting process. Therefore, the roots have stronger absorption capacity and require more calcium and boron. Therefore, they have higher soil requirements.
1. Soil highly matured
The content of organic matter is required to reach 2% to 3%, preferably 3% to 4%. The total porosity is about 60%. The depth of groundwater is less than 2.5 meters and the best soil is loamy soil.
2. Good farming
The suitable soil bulk density for vegetables is 1.1-1.3 g/cm3, and the soil hardness after cultivating the vegetable garden is preferably 20-30 kg/cm2, and more than 30 kg/cm2 will have an adverse effect on the root system.
3 good temperature and humidity
The soil temperature stability is closely related to the specific heat and heat conductivity of the soil. The humified loam has the highest specific heat, and the clay soil and organic-rich soils have moderate heat capacity and good temperature stability.
4. Contains higher nutrient content
Requires total nitrogen content of 0.1% or more, alkaline hydrolysis nitrogen 75 mg/kg or more, available potassium 150 mg/kg or more, available phosphorus 30 mg/kg or more, magnesium oxide 150 to 240 mg/kg, calcium oxide 0.1% to 0.14%, At the same time contains a certain amount of boron, manganese, zinc, copper, iron, molybdenum and other trace elements. The soil salt content does not exceed 0.4%, with slightly acidic.
5. Strong water storage and oxygen supply capacity
When the maximum water holding capacity is reached in the field, it is required that the soil can maintain oxygen content of more than 15%.
The effect of soil problems on vegetables
1. Soil organic matter is lacking and yield is declining
Soil compaction, a serious lack of organic matter, mainly due to the large number of application of chemical fertilizers, the annual neglect of the application of organic fertilizer, resulting in poor soil permeability, microbial reduction, poor root development will be vulnerable to disease. For many years, continuous cropping leads to insufficient trace elements in soil and aggravated salinization seriously affects the growth of vegetables.
2. The plough layer becomes shallow, affecting the development of the root system
The soil plough layer is shallow, and the vegetable field is mostly digging by hand. The intercropping and interplanting of the cultivars is less. The soil layer is gradually shallow and the root extension is affected.
3. Increase in pests and other harmful substances
Deterioration of the soil will also lead to an increase in pests and diseases. In the process of growing vegetables, due to unreasonable fertilization and pesticide application, the problem of soil pollution will become increasingly serious and cause food safety incidents.
Improvement measures
1. Increase organic fertilizer
After organic manure is applied, the organic matter in the soil is replenished, water, fertilizer, and gas are coordinated and developed, and a good growth environment is created for the growth of the vegetables, ensuring the growth of roots, stems and leaves.
2. Deep plowing soil
In combination with organic fertilizers, the soil is deeply ploughed to increase the permeability of the soil and promote soil ripening. It can also increase the effectiveness of organic fertilizers. After the general vegetable is planted, it should be scratched once every 3-5 days, and the depth should be 3 cm.
3. Rational rotation
To rotate vegetables properly, such as deep-rooted legumes, melons, and solanaceous fruit, with shallow-rooted Chinese cabbage, cabbage, cucumber, onion and garlic, etc. to make full use of different soil nutrients to improve soil fertility. Reduce bacterial accumulation.
4. Increase soil microbial content
After a long period of continuous cropping, vegetables have accumulated a large amount of harmful substances, and beneficial microorganisms have gradually decreased. It is possible to improve soil compaction, release nutrients, and promote crop root growth by applying microbial fertilizer.
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