Corn is an indicator of many elements, such as nitrogen, potassium, calcium, magnesium, and zinc. How to apply scientific fertilization according to the growth characteristics of spring maize and the fertilizer requirement is very important to improve the yield of spring corn.
A physiological disease caused by malnutrition is called deficiency. There is a general difference between the lack of large amounts of elements and the lack of external morphological features of micronutrients. Nitrogen deficiency, seedling dwarf, thin, leaf cluster yellow-green; leaves turn yellow from the tip of the leaf, develop along the midrib of the leaf, forming a "V"-shaped yellowing part; causing the whole plant to yellow, the lower part of the blade is dead and edge Yellow-green; severe nitrogen deficiency or nitrogen deficiency in critical periods, small ear, no top grain, low protein content. Phosphorus deficiency, tender plant sensitivity, plant dwarfing; leaf tip, leaf margin chlorotic is purple-red, posterior leaf end dead or dark purple brown; roots are underdeveloped, female pollination is blocked, grain is not full, ear is small or distortion . In the absence of potassium, the tip and leaf margin of the lower leaves are yellow or red-hot, and the plants are easy to fall and the ears are small. Zinc deficiency is caused by excessive phosphorus in soil or fertilizer, and soils with high pH, ​​low temperature, high humidity or low organic fertilizer are prone to zinc deficiency.
Corn is a gramineous crop. According to its fertility characteristics, it can be divided into three important stages: seedling stage, ear stage and flower stage. Corn absorbs the most nitrogen in its lifetime, followed by potassium and phosphorus. Generally speaking, for every 100kg of corn kernels produced, it is necessary to absorb 2.5~4.0kg of nitrogen, 1.1~1.4kg of phosphorus and 3.2~5.5kg of potassium from the soil, the ratio of which is 1:0.4:1.3. The absorption of NPK is different in corn at different growth stages. Studies have shown that the nitrogen uptake of spring maize seedlings is less, accounting for only 2.14% of the total nitrogen; the most absorbed at booting stage, accounting for 32.20% of the total; the uptake during heading and flowering accounts for 18.95% of the total; During the grain formation stage, the absorption amounted to 46.7% of the total. The absorption of phosphorus by spring maize accounted for 1.12% of the total amount in the seedling stage, and 45.04% of the total amount absorbed during the jointing and booting stage. At the stage of heading fertilization and grain formation, the absorption amounted to 53.84% of the total. The absorption of potassium by corn is similar to that of summer maize. More than 70% of the corn is absorbed before heading, and 30% is absorbed during heading and fertilization. The dry matter accumulation of maize is closely related to the nutrient level. The absorption of the three elements of NPK is less than that of the seedling stage, the jointing period is significantly increased, and the fertilizer requirement is the highest peak from the booting stage to the heading stage. Therefore, according to this feature, corn fertilization should be fertilized as much as possible before the peak of fertilizer demand.
The principle of fertilization of spring corn: mainly based on base fertilizer and supplemented by topdressing; farmyard manure is mainly supplemented by chemical fertilizer; nitrogen fertilizer is the main, phosphate fertilizer is supplemented; panicle fertilizer is the main, and grain fertilizer is supplemented. Organic fertilizer, all phosphorus and potassium fertilizers and 1/3 nitrogen fertilizer were applied as base fertilizer.
When applying the base fertilizer, it should be evenly mixed with the soil. Generally, 37500~60000kg of farmyard manure can be applied per hectare. If nitrogen fertilizer is used as the base fertilizer, 200~300kg of bicarbonate or 50~75kg of urea can be applied per hectare. Must be applied in depth to prevent nitrogen loss. In the phosphorus-deficient soil, 450-600 kg of calcium phosphate per hectare is applied; in the potassium-deficient soil, 150 kg of potassium chloride per hectare is applied; in the zinc-deficient soil, 15 kg of zinc sulfate heptahydrate is applied per hectare. Before the spring sowing, use a small amount of farmyard manure to match the appropriate nitrogen and phosphorus fertilizers or apply as a corn seed fertilizer. Corn topdressing is an important measure for high-yield corn cultivation. It is mostly applied before and after heavy fertilization, that is, corn is applied to 1/3 of top dressing before jointing, and 75~150kg per hectare of urea. 2/3 of the topdressing fertilizer, 150~300kg of urea per hectare, which is 13.3% higher than that of the former heavy and light fertilization method.
(Author: Institute of Environmental Sciences and Natural Resources)
Source: Farmers Daily Author: Hou Yanlin
A physiological disease caused by malnutrition is called deficiency. There is a general difference between the lack of large amounts of elements and the lack of external morphological features of micronutrients. Nitrogen deficiency, seedling dwarf, thin, leaf cluster yellow-green; leaves turn yellow from the tip of the leaf, develop along the midrib of the leaf, forming a "V"-shaped yellowing part; causing the whole plant to yellow, the lower part of the blade is dead and edge Yellow-green; severe nitrogen deficiency or nitrogen deficiency in critical periods, small ear, no top grain, low protein content. Phosphorus deficiency, tender plant sensitivity, plant dwarfing; leaf tip, leaf margin chlorotic is purple-red, posterior leaf end dead or dark purple brown; roots are underdeveloped, female pollination is blocked, grain is not full, ear is small or distortion . In the absence of potassium, the tip and leaf margin of the lower leaves are yellow or red-hot, and the plants are easy to fall and the ears are small. Zinc deficiency is caused by excessive phosphorus in soil or fertilizer, and soils with high pH, ​​low temperature, high humidity or low organic fertilizer are prone to zinc deficiency.
Corn is a gramineous crop. According to its fertility characteristics, it can be divided into three important stages: seedling stage, ear stage and flower stage. Corn absorbs the most nitrogen in its lifetime, followed by potassium and phosphorus. Generally speaking, for every 100kg of corn kernels produced, it is necessary to absorb 2.5~4.0kg of nitrogen, 1.1~1.4kg of phosphorus and 3.2~5.5kg of potassium from the soil, the ratio of which is 1:0.4:1.3. The absorption of NPK is different in corn at different growth stages. Studies have shown that the nitrogen uptake of spring maize seedlings is less, accounting for only 2.14% of the total nitrogen; the most absorbed at booting stage, accounting for 32.20% of the total; the uptake during heading and flowering accounts for 18.95% of the total; During the grain formation stage, the absorption amounted to 46.7% of the total. The absorption of phosphorus by spring maize accounted for 1.12% of the total amount in the seedling stage, and 45.04% of the total amount absorbed during the jointing and booting stage. At the stage of heading fertilization and grain formation, the absorption amounted to 53.84% of the total. The absorption of potassium by corn is similar to that of summer maize. More than 70% of the corn is absorbed before heading, and 30% is absorbed during heading and fertilization. The dry matter accumulation of maize is closely related to the nutrient level. The absorption of the three elements of NPK is less than that of the seedling stage, the jointing period is significantly increased, and the fertilizer requirement is the highest peak from the booting stage to the heading stage. Therefore, according to this feature, corn fertilization should be fertilized as much as possible before the peak of fertilizer demand.
The principle of fertilization of spring corn: mainly based on base fertilizer and supplemented by topdressing; farmyard manure is mainly supplemented by chemical fertilizer; nitrogen fertilizer is the main, phosphate fertilizer is supplemented; panicle fertilizer is the main, and grain fertilizer is supplemented. Organic fertilizer, all phosphorus and potassium fertilizers and 1/3 nitrogen fertilizer were applied as base fertilizer.
When applying the base fertilizer, it should be evenly mixed with the soil. Generally, 37500~60000kg of farmyard manure can be applied per hectare. If nitrogen fertilizer is used as the base fertilizer, 200~300kg of bicarbonate or 50~75kg of urea can be applied per hectare. Must be applied in depth to prevent nitrogen loss. In the phosphorus-deficient soil, 450-600 kg of calcium phosphate per hectare is applied; in the potassium-deficient soil, 150 kg of potassium chloride per hectare is applied; in the zinc-deficient soil, 15 kg of zinc sulfate heptahydrate is applied per hectare. Before the spring sowing, use a small amount of farmyard manure to match the appropriate nitrogen and phosphorus fertilizers or apply as a corn seed fertilizer. Corn topdressing is an important measure for high-yield corn cultivation. It is mostly applied before and after heavy fertilization, that is, corn is applied to 1/3 of top dressing before jointing, and 75~150kg per hectare of urea. 2/3 of the topdressing fertilizer, 150~300kg of urea per hectare, which is 13.3% higher than that of the former heavy and light fertilization method.
(Author: Institute of Environmental Sciences and Natural Resources)
Source: Farmers Daily Author: Hou Yanlin
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