First, the symptoms of calcium deficiency in vegetables
Calcium deficiency is mainly caused by the physiological disorders of metabolism in crops. Generally, acidic soils are prone to calcium deficiency. In the absence of calcium, the apical buds, lateral buds, apical meristems and other meristems of plants first exhibit deficiency of nutrients, the growth of plants is blocked, the internodes are short, the plants are short and soft, and the young leaves are curlyly deformed, fragile, and often lacking in engraved leaves. The edge is yellow and gradually withered. The tips of the leaves are sticky, and they are not strong or rarely strong. Such as cabbage, cabbage and lettuce, calcium deficiency occurs leaf char, tomato, pepper, watermelon and other calcium deficiency will appear umbilical rot. The symptoms of calcium deficiency in several vegetables are as follows:
1. Cabbage leaf edge decomposed rot, leaves the edge of water immersion, to brown necrosis, dry skin like tofu, also known as dry heartburn, dry edge, internal superficial burning disease.
2. Tomatoes lack calcium and the tips of the young leaves are yellow, the plants are thin and wilting, the petiole is curled, the apical buds are dead, necrotic tissue appears around the terminal buds, the roots are undeveloped, the roots are short, and the branches are numerous and brown. The fruit is prone to heart rot or empty fruit.
3. The calcium-deficient leaves and veins of cucumber showed white transparent rotting spots. The veins were dark between severe veins, the plants were dwarfed, the young leaves were rolled up, the flowers were small yellowish-white, and the melons were small and tasteless.
4. The growth of lettuce was inhibited by calcium deficiency, and the young leaves were curled and deformed. The leaf margin was brown to gray. In severe cases, the young leaves die from the top to the inside, and the dead tissue is gray-green.
5. Cabbage leaves lacking calcium curl, colorless, with white streak, growth point of death.
6. Carotid defoliation leaves chlorosis, necrosis, eventual death, sparse leaves.
7. The celery calcium-deficient young leaves died early, the growth was weak, the leaves were gray-green, the growth points died, and the tips of the tips of the lobule were twisted and turned black.
Second, excessive calcium in vegetables symptoms
Excessive application of calcium fertilizer under field conditions can cause abnormal growth and metabolism of vegetable plants, and has no significant effect on the yield and quality of vegetables, but it can easily cause the decrease of trace elements such as zinc, iron and manganese.
Third, suitable for vegetable calcium fertilizer types and application methods
1. Limestone contains calcium carbonate 95%--98%. Limestone is ground into limestone powder after passing through a 1.5mm sieve. Large application will not cause the soil to be too alkaline.
2. Gypsum contains more than 80% of calcium sulphate, and agricultural gypsum is obtained by crushing gypsum ore over a pore size of 0.25 mm, and is a white or gray powder. In addition to providing calcium nutrition for crops, sulfur can also be provided.
3. Calcium nitrate contains 19% of water-soluble calcium, 15.5% of nitrogen, and is easily hygroscopic. It is sealed during storage. The aqueous solution is acidic.
4. Lime includes quicklime and hydrated lime, which is commonly used in the production of calcium fertilizer.
Quicklime, limestone is calcined to produce lime, also known as lime, containing 90% - 96% of calcium oxide, strong alkaline, very strong hygroscopicity, as a white powder or in the form of a block, the ability to neutralize the acidity of the soil is very strong. Excessive application of quicklime will lead to a decline in the effectiveness of nutrients such as iron, manganese, zinc, copper, and boron in cultivated soil, and even induce nutrient deficiency, which is not conducive to the growth of vegetables.
The hydrated lime and quicklime change the mature lime, and release a lot of heat when absorbing water. It is also called slaked lime, containing about 70% of calcium oxide, strong alkalinity, and the ability to neutralize the acidity of the soil is weaker than the quicklime.
Application of lime is beneficial to reduce disease, increase yield, improve quality, increase soil pH and improve soil structure. In acid-strong soils, lime can eliminate aluminum toxicity, increase the amount of calcium adsorbed on the surface of soil colloids, improve the stability, aeration and permeability of the soil structure, the normal growth and development of crops, and promote soil The activity of beneficial microorganisms accelerates the decomposition of organic matter and nutrient release, and increases the availability of phosphorus in soil. Lime is a strong alkaline substance that kills germs and eggs in the soil and eliminates weeds.
The application amount of lime is related to soil type, pH, crop type and application purpose. Generally, 40--80kg of quicklime or hydrated lime is appropriate for every 667 square meters of soil. The application of lime in acid soils such as upland red soil is better, and it should be applied more frequently. Little or no application of slightly acidic and neutral soils is possible. In contrast to sandy soil, the amount of lime should be appropriately reduced. Generally, 50--75 kg per 667 square meters is applied.
Can be used as basal fertilizer and top dressing, but not as a fertilizer. As a basal fertilizer, the lime is applied together with the farmyard fertilizer when the soil is prepared, and it can also be combined with green manure and greening. 50--70kg for every 667m2 of vegetable land, 150--250kg for 667m2 of land. When planting soybeans, roots and other hi-calcium vegetables in calcium-depleted soil, use 15-25 kg of lime per 667 square meters and apply them to a hole or a hole. Cruciferous vegetables such as radish and Chinese cabbage are mixed with lime and organic fertilizer during seedling transplanting, which can also effectively prevent clubroot disease. For topdressing, lime is not used as a base fertilizer for soil preparation. Lime can be applied during the growing period of vegetables.
Note that lime should not be used excessively, as lime is strongly alkaline and should be applied evenly. When using ditch and hole, contact with seeds or roots should be avoided. The application of lime must be combined with the application of organic fertilizers and nitrogen, phosphorus, and potassium fertilizers, but lime and human urine and ammonium nitrogen fertilizers must not be stored, mixed or stored together with superphosphate. Lime has a residual effect of 2- 3a. When the amount of lime is larger, the application amount in the second and third years can be gradually reduced, and then the application can be stopped after 2a.
Calcium deficiency is mainly caused by the physiological disorders of metabolism in crops. Generally, acidic soils are prone to calcium deficiency. In the absence of calcium, the apical buds, lateral buds, apical meristems and other meristems of plants first exhibit deficiency of nutrients, the growth of plants is blocked, the internodes are short, the plants are short and soft, and the young leaves are curlyly deformed, fragile, and often lacking in engraved leaves. The edge is yellow and gradually withered. The tips of the leaves are sticky, and they are not strong or rarely strong. Such as cabbage, cabbage and lettuce, calcium deficiency occurs leaf char, tomato, pepper, watermelon and other calcium deficiency will appear umbilical rot. The symptoms of calcium deficiency in several vegetables are as follows:
1. Cabbage leaf edge decomposed rot, leaves the edge of water immersion, to brown necrosis, dry skin like tofu, also known as dry heartburn, dry edge, internal superficial burning disease.
2. Tomatoes lack calcium and the tips of the young leaves are yellow, the plants are thin and wilting, the petiole is curled, the apical buds are dead, necrotic tissue appears around the terminal buds, the roots are undeveloped, the roots are short, and the branches are numerous and brown. The fruit is prone to heart rot or empty fruit.
3. The calcium-deficient leaves and veins of cucumber showed white transparent rotting spots. The veins were dark between severe veins, the plants were dwarfed, the young leaves were rolled up, the flowers were small yellowish-white, and the melons were small and tasteless.
4. The growth of lettuce was inhibited by calcium deficiency, and the young leaves were curled and deformed. The leaf margin was brown to gray. In severe cases, the young leaves die from the top to the inside, and the dead tissue is gray-green.
5. Cabbage leaves lacking calcium curl, colorless, with white streak, growth point of death.
6. Carotid defoliation leaves chlorosis, necrosis, eventual death, sparse leaves.
7. The celery calcium-deficient young leaves died early, the growth was weak, the leaves were gray-green, the growth points died, and the tips of the tips of the lobule were twisted and turned black.
Second, excessive calcium in vegetables symptoms
Excessive application of calcium fertilizer under field conditions can cause abnormal growth and metabolism of vegetable plants, and has no significant effect on the yield and quality of vegetables, but it can easily cause the decrease of trace elements such as zinc, iron and manganese.
Third, suitable for vegetable calcium fertilizer types and application methods
1. Limestone contains calcium carbonate 95%--98%. Limestone is ground into limestone powder after passing through a 1.5mm sieve. Large application will not cause the soil to be too alkaline.
2. Gypsum contains more than 80% of calcium sulphate, and agricultural gypsum is obtained by crushing gypsum ore over a pore size of 0.25 mm, and is a white or gray powder. In addition to providing calcium nutrition for crops, sulfur can also be provided.
3. Calcium nitrate contains 19% of water-soluble calcium, 15.5% of nitrogen, and is easily hygroscopic. It is sealed during storage. The aqueous solution is acidic.
4. Lime includes quicklime and hydrated lime, which is commonly used in the production of calcium fertilizer.
Quicklime, limestone is calcined to produce lime, also known as lime, containing 90% - 96% of calcium oxide, strong alkaline, very strong hygroscopicity, as a white powder or in the form of a block, the ability to neutralize the acidity of the soil is very strong. Excessive application of quicklime will lead to a decline in the effectiveness of nutrients such as iron, manganese, zinc, copper, and boron in cultivated soil, and even induce nutrient deficiency, which is not conducive to the growth of vegetables.
The hydrated lime and quicklime change the mature lime, and release a lot of heat when absorbing water. It is also called slaked lime, containing about 70% of calcium oxide, strong alkalinity, and the ability to neutralize the acidity of the soil is weaker than the quicklime.
Application of lime is beneficial to reduce disease, increase yield, improve quality, increase soil pH and improve soil structure. In acid-strong soils, lime can eliminate aluminum toxicity, increase the amount of calcium adsorbed on the surface of soil colloids, improve the stability, aeration and permeability of the soil structure, the normal growth and development of crops, and promote soil The activity of beneficial microorganisms accelerates the decomposition of organic matter and nutrient release, and increases the availability of phosphorus in soil. Lime is a strong alkaline substance that kills germs and eggs in the soil and eliminates weeds.
The application amount of lime is related to soil type, pH, crop type and application purpose. Generally, 40--80kg of quicklime or hydrated lime is appropriate for every 667 square meters of soil. The application of lime in acid soils such as upland red soil is better, and it should be applied more frequently. Little or no application of slightly acidic and neutral soils is possible. In contrast to sandy soil, the amount of lime should be appropriately reduced. Generally, 50--75 kg per 667 square meters is applied.
Can be used as basal fertilizer and top dressing, but not as a fertilizer. As a basal fertilizer, the lime is applied together with the farmyard fertilizer when the soil is prepared, and it can also be combined with green manure and greening. 50--70kg for every 667m2 of vegetable land, 150--250kg for 667m2 of land. When planting soybeans, roots and other hi-calcium vegetables in calcium-depleted soil, use 15-25 kg of lime per 667 square meters and apply them to a hole or a hole. Cruciferous vegetables such as radish and Chinese cabbage are mixed with lime and organic fertilizer during seedling transplanting, which can also effectively prevent clubroot disease. For topdressing, lime is not used as a base fertilizer for soil preparation. Lime can be applied during the growing period of vegetables.
Note that lime should not be used excessively, as lime is strongly alkaline and should be applied evenly. When using ditch and hole, contact with seeds or roots should be avoided. The application of lime must be combined with the application of organic fertilizers and nitrogen, phosphorus, and potassium fertilizers, but lime and human urine and ammonium nitrogen fertilizers must not be stored, mixed or stored together with superphosphate. Lime has a residual effect of 2- 3a. When the amount of lime is larger, the application amount in the second and third years can be gradually reduced, and then the application can be stopped after 2a.