To top dressing corn, 40 kilograms of urea per acre of land but 40 kilograms of urea are used, what

Corn topdressing uses 40 catties of urea for one acre, but you use 40 kilograms, that is, 80 catties, causing the leaves to turn yellow, and there are no dead seedlings, indicating that you are lucky, because at this time, through measures to save in time, but also to make the corn quickly return to normal growth, and the leaves turn green.

As a physiological neutral solid fertilizer with the highest nitrogen content, urea is better to use base fertilizer or top dressing and foliar spraying, but the amount should not be too much when used, otherwise it will have no adverse effect on growth, such as plant growth, or fertilizer root burning, leaf yellowing, and even dead seedlings, etc., especially when the root urea dosage is too much, it usually leads to root burning due to the following reasons, resulting in leaf yellowing and not long, and even dead seedlings.

First of all, the soil is arid, when a large amount of urea is applied near the root system, and urea has the habit of hygroscopic deliquescent, so that the water in the soil is easy to be adsorbed by urea, when the urea is dissolved, the concentration of water solution in the soil increases significantly, due to the different osmotic pressure inside and outside the root system, resulting in the penetration of water in the root system to the outside of the root, and then the plant lacks water, and the nutrients are insufficient and yellow. Secondly, the top dressing is too close to the root system, and when a large amount of urea is decomposed, it will cause too much ammonia ion concentration near the root system, causing root ammonia ion poisoning, and then causing leaves. Finally, urea is applied to the soil more shallowly, or covered with thin soil, so that the urea decomposes to form ammonia and the fumigation leaves turn yellow when volatilization.

Generally, the higher the temperature, the more powerful the ammonia volatilization and fumigation leaves.

After the amount of urea is too large, it will not cause dead seedlings in the short term, unless the soil is dry and water shortage is serious, so for the field with only yellow leaves after fertilization, it is necessary to first timely foliar spray with detoxification and detoxification, and can repair damaged and injured cells in time, and can significantly enhance the stress resistance of plants and regulate the growth of agents, such as Bihu, or brassinin or baitin and other active foliar fertilizers such as American star or alginic acid are better. Generally, it can be sprayed with 3-4 grams of Bihu plus 30-50 ml of American star foliar fertilizer per mu, for soil moisture is sufficient, usually sprayed once, and the drought is insufficient after the field is generally relieved and improved, it can be sprayed once in time.

Secondly, if there are conditions, it should be watered in time, especially in the vicinity of the root system, which can reduce the concentration of fertilizer near the root system, reduce the poisoning of ammonia ions in the root system, and also prevent the root system from losing water, repair and grow the root system, enhance the photosynthesis of the plant, and make the leaf growth green better. Corn grows best when it is robust.

In short, after the yellowing of corn fertilizer leaves, timely rescue measures can be quickly alleviated and improved, so as to restore normal growth. However, in corn topdressing should be based on the growth, weather, etc., grasp the dosage evenly for hole application or strip application, and pay attention to deep soil covering, avoid high temperature topdressing, and watering in time after fertilization with insufficient moisture in the field, which can effectively prevent fertilizer damage.

The yellowing of the leaves may be due to inadequate watering. So be sure to water the corn a lot at this time. Also provide light.

In this case, corn needs to be irrigated, especially the root system should be irrigated with enough water, dilute the concentration of urea, and prevent the root system from running out of water, or the corn leaves can be sprayed with anti-stress drugs in time, and then irrigation.

The reason for the yellowing of the leaves is that too much fertilizer is used, and the concentration in the soil is too high, which causes the seedlings to burn. You can spray some water properly to dilute off the fertilizer.

40 kg of urea or potassium phosphate (30-5-5) ratio close to about 50 kg of compound fertilizer, with deep application of about 5-10 cm is the best. Top dressing at the ear stage is generally applied from the corn plant 15 to 20 cm, in strips or holes. Note:

Sometimes three ingredients can be added. If the seedlings are weak at the jointing stage (5-6 leaf stage) after the first fertilization, nitrogen and water-soluble fertilizer should be applied in time, which is fast to dissolve and has a high absorption rate.

40 kg of fertilizer per mu, applied in ditches or holes, with an application depth of 5-7 cm. Conditionally, organic fertilizer can be added, organic fertilizer is about 10 cm deep, corn plants can be removed 15-20 cm in the ditch, apply organic fertilizer, chemical fertilizer, etc. once, and if conditions can be combined with 2 billion live bacteria of Yanwo microbial agent, it contains Trichoderma harzianum, so that crops can better absorb nutrients and improve the effect of fertilizer.

In addition, "shelling" is best to apply controlled-release fertilizer, and the ratio of nitrogen, phosphorus and potassium (28-5-9) is close to optimal, the number of acres of fertilizer is 80 catties, and fertilizer can be planted or 3 leaf stage joint time one-time application. It should be noted that in order to prevent the seedlings from burning during fertilization, holes or strips should be made at a depth of 6-8 cm from the plant at a depth of 7-10 cm. Most of the areas with general fertilizer retention can be divided into two and three applications.

In principle, phosphorus and potassium fertilizers are fully applied, and nitrogen fertilizers are generally not higher than 20% and 30% of the total nitrogen rate.

If the bottom fertilizer in the early stage is wet enough, 50 catties of one acre of land should be used for top dressing. Equivalent to 25 kg. If the bottom fertilizer is slightly less, about 70 catties per acre. Equivalent to 35 kg.

When corn urea is used as foliar fertilizer, the dosage should be moderate, otherwise it may adversely affect the crop. It is usually recommended to control the dosage per mu at about 500-600 grams. The specific dosage needs to be adjusted according to local soil fertility conditions, climatic conditions, corn varieties and other factors.

The following points should be paid attention to when using Heng Shu Pei:

Make sure the corn is in a healthy state: Foliar fertilizer is not recommended if the crop has grown with obvious pests, diseases or nutritional disorders, so as not to increase the burden on the crop.

Avoid using foliar fertilizers in high temperatures, bright light and high humidity conditions, which can increase the risk of crop damage.

It should be sprayed evenly when used to avoid burning the leaves due to excessive concentration.

In the early stage of corn growth or when the growth is slow, increasing the amount of foliar fertilizer can help to improve the growth rate and yield of corn.

In short, when using corn foliar fertilizer, attention should be paid to the appropriate amount and correct use method to avoid adverse effects on crops.

The amount of corn urea as foliar fertilizer should be mastered at the most appropriate, that is, in 100 kg of water, add 50 grams to 100 grams of urea.

Corn fertilization technology.

1. The principle of fertilization.

The combination of organic fertilizer and inorganic fertilizer, nitrogen, phosphorus, potassium and micro fertilizer, and balanced fertilization can achieve the purpose of improving sudden fertility and increasing yield.

2. Fertilization method.

1) Base fertilizer. Corn-based fertilizer is mainly organic fertilizer. The application methods of basal fertilizer include sprinkling, strip application and hole application, which vary depending on the quantity and quality of basal fertilizer.

In the high-yield field of spring maize, 30,000kg of organic fertilizer and mixed inorganic chemical fertilizer were applied to each project, combined with autumn ploughing. Organic fertilizer has complete nutrients and long fertilizer efficiency, which has the effect of soil modification and fertilization, reduces the fixation of nutrients in the soil, improves the fertilizer efficiency of chemical fertilizer and reduces the cost of leaseback production in the town. Therefore, many experts in China advocate that the pure nitrogen ratio of organic fertilizer and inorganic fertilizer should be maintained at 7:

3。2) Seed the world to search for fertilizer.

Combined with the seed fertilizer applied by sowing, it is mainly to meet the nutrient needs of seedlings and cultivate strong seedlings. In spring maize fields with low soil fertility, low amount of basal fertilizer or no basal fertilizer, the effect of applying seed fertilizer to increase yield was more significant. The seed fertilizer is applied in strips or holes, and is applied under or to the side of the seeds, so that they are isolated from the seeds or mixed with the soil to prevent the seedlings from burning.

3) Top dressing. The period, frequency and quantity of top dressing should be determined according to the law of corn fertilizer demand, soil fertility base, fertilizer quantity, basal fertilizer and seed fertilizer application and corn growth status. Spring corn topdressing can be divided into three applications: tapping stalks, tapping ears and tapping grains.

For the first time, after 7-8 leaves, around June 15, the leaves applied to the spring corn at the jointing stage are called tapping fertilizer. The main purpose of this topdressing is to promote the healthy growth of spring maize plants and facilitate the differentiation of male and female panicles. The second time in the spring corn 11-12 leaves, around July 10, is the spring corn big flare period, this top dressing is also called ear fertilizer.

This topdressing promotes the enlargement of the middle and upper leaves of spring maize, prolongs its functional period, and promotes the good differentiation and development of male and female ears, which is extremely important to ensure large ears and many grains, and is an efficient period for spring maize top dressing. The third is the fertilizer that is topdressed after the spring corn is pumped and spit out the royal simula, also known as grain fertilizer. Grain fertilizer plays an important role in reducing floret abortion, increasing the number of grains, preventing and controlling off-target and premature leaf senescence in the later stage, improving the photosynthetic efficiency of leaves, ensuring grain filling, and increasing grain weight.

In addition, the spraying of potassium dihydrogen phosphate and micro-fertilizer at the flowering stage had the effect of promoting grain formation, early maturity and increasing yield.

Whether to use urea or foliar fertilizer for corn topdressing needs to be selected according to the specific situation.

Under normal circumstances, urea can be used for corn topdressing, which is also the fertilizer used by most farmers. Corn is a nitrogen-loving crop, so during the whole growth period, the nitrogen fertilizer can not be broken. Under normal circumstances, the bottom fertilizer is normal, and when it reaches the big bell stage, 20-25 kg of urine laughing hormone can be applied to one acre of land.

However, the corn in different plots has different growth, and there are also cases of choosing compound fertilizer, such as the plots that have not applied base fertilizer, a single topdressing urea will not work, phosphate fertilizer and potassium fertilizer should also be supplemented, so it is necessary to topcoat compound fertilizer, and the amount of compound fertilizer can not be too little, about 30-40 kg, according to the growth of corn, the state imitation of 50 kg per mu is also available.

In addition to corn fields without base fertilizer, plots with relatively poor soil, or low-lying plots, it is also recommended to choose compound fertilizer when topdressing corn. For the phenomenon that corn has turned purple and red, it is also necessary to apply compound fertilizer in time and supplement phosphate fertilizer and potassium fertilizer.

Therefore, corn topdressing is urea or foliar fertilizer, need to be selected according to the specific situation, urea can be used to save some costs, foliar fertilizer can be used to save some costs, foliar fertilizer can be used, and the yield can not be reduced in order to save costs.

Hello friends, if you use too much urea when planting corn, it may lead to the following problems:1Burnt seedlings:

Excessive urea content of bottom fertilizer will increase the pH of soil, affect the germination and growth of corn seeds, and lead to seedling burning. 2.Dwarf:

Excess nitrogen may lead to dwarfing of maize, affecting the growth and yield of maize. 3.Renders green:

Excessive nitrogen levels can cause the plants to overgrow and appear green, and the leaves will become thicker, affecting the yield of corn. If the bottom fertilizer urea is used too much, the following countermeasures can be carried out:1

Patient observation: Observe the growth status of corn in the early stage, and take countermeasures in time if it is found that it is not normal. Wild which 2

Improve ventilation: Increased ventilation can help volatilize nitrogen and reduce nitrogen levels in the soil. 3.

Add phosphate fertilizer: Adding an appropriate amount of phosphorus fertilizer to the base fertilizer can neutralize the excess nitrogen and potassium in the soil and accelerate the absorption of phosphorus by plants. 4.

Timely irrigation: Ensure soil moisture and minimize the impact of residual nitrogen on maize. 5.

Reduce the amount of fertilizer: Minimize fertilizer and supplement root and foliar fertilizer at the right time.