Urea is too expensive to waste! Unfortunately, many farmers are not right! How exactly do you use it?
When it comes to urea, everyone is familiar with it. Urea is the most commonly used nitrogen fertilizer with nitrogen content ≥46%. It is an instant fertilizer with the highest nitrogen content and is widely used in a variety of crops.
However, the utilization rate of urea is low, generally only about 20%-30%, most of the urea applied to the soil is lost with water or volatilization loss. This is mainly because urea, when applied to the soil, can't be directly absorbed by crops, It is hydrolyzed into ammonium carbonate or ammonium bicarbonate under the action of urease. Ammonium ions can be absorbed by plants and absorbed by soil colloid, but under the condition of flooding or alkaline soil, it is easy to generate ammonia volatilization.
In addition, some of the unadsorbed ammonium ions are lost as water seeps into the ground. This is the main reason for the low utilization rate of urea. Therefore, how to improve the utilization rate of urea has become the key in the production process.
To improve the utilization rate of urea, we can advance deep application or foliar spraying form. Today, we mainly talk about how urea foliar spraying, and recommend a small formula, that is, potassium dihydrogen phosphate + urea, spraying together, has a significant effect of increasing production and improving quality.
1. Leaf spraying urea method
Urea is amide nitrogen fertilizer, small molecule, strong ability to cross cell membrane, urea can quickly enter the leaf, and then participate in a variety of metabolism, generally speaking, half an hour after leaf spraying can be absorbed, and transferred to each part of the plant, the utilization rate is greatly improved.
According to the test, through leaf spraying, urea utilization rate can reach 70%-100%, which is 2 times of soil topdressing. Therefore, in the middle and late stage of crop growth, urea can be sprayed at a certain proportion on the leaf surface, which can quickly supplement the nitrogen fertilizer needed by the crop and prevent the occurrence of defertilization or premature aging of the plant.
Generally speaking, crops in the seedling period, early flowering, late anti-premature senility of nitrogen demand is more, so we often spray urea in this time period!
For best absorption, apply before 10 a.m. or in the evening with a sprayer 45 degrees up at an Angle. The general interval of about 15 days spray can be! Of course, sometimes in order to improve the efficacy, we can also add 3 pinch washing powder or agricultural silicone additives!
The commonly used spraying concentration is 1%-1.5%. Specific preparation method: take 1-1.5 kg urea add 100 kg water, fully dissolved can be sprayed. The concentration can be adjusted appropriately according to crop species, such as dicotyledons, the concentration can be appropriately lower; If it is a monocotyledon plant, the concentration can be appropriately higher; In the seedling period of the crop, the concentration is appropriately low, and in the seedling period, the concentration can be appropriately high. Do not exceed the concentration range of 1%-1.5%.
However, urea is used as foliar fertilizer, the range of spraying concentration is not absolute, such as spraying on cereal crops, the concentration can be in 1%-2%; Spray on vegetables, melons and fruits, concentration in 0.5%-1%;
However, special care should be taken to spray urea at a concentration of no more than 0.2% on seedlings during the seedling period.
Also remind you that if you buy urea products, the content of biuret exceeds 1%, shall not be sprayed as foliar fertilizer, because it will cause "burning seedlings" fertilizer harm. Urea products are now required to indicate the content of biuret on the package, pay attention to check the packaging instructions when buying. Urea and potassium dihydrogen phosphate can be mixed, but you have to remember to mix them.
2. Use with potassium dihydrogen phosphate
Potassium dihydrogen phosphate phosphorus and potassium are the main ingredients, on the one hand, it can accelerate the formation of the crop sugar, carbohydrates and transportation, so as to promote crop metabolism and nutrient supply, on the one hand, it can increase the crop of the content of soluble sugar and phospholipids, thereby reducing the cytoplasm freezing point, enhance crop cold frost resistance.
On the one hand, potassium ions can improve the permeability of cells and promote the absorption of water by crops, so as to play the role of drought resistance; On the other hand, phosphorus can not only promote seed germination, root development and flower bud differentiation; On the other hand, it can promote the wood aging of the fiber bundles in the plant stem and the conversion of compounds in the plant from low to high, which not only enhances the toughness and robustness of the crop stem, but also greatly improves the lodging resistance and disease resistance of the crop.
Potassium dihydrogen phosphate can be used in the entire crop fertility period, almost in prophase (seedling stage) in general, according to the concentration of 0.05 to 0.1%, in order to speed up the crop plant growth, root development, make sprout even sprout strong, in the mid-late crop phosphorus potassium peak demand (and) use effect is better, can not only accelerate the flower bud differentiation, prevent premature aging, and promote early, At the same time, it has a very good effect on increasing output and improving quality. Generally, it is used in accordance with the concentration of 0.2-0.3%.
Potassium dihydrogen phosphate plus urea can supplement the three main elements of nitrogen, phosphorus and potassium at the same time, and supplement the nutrients consumed by crops such as flowering. At the same time, the combination of the two can be absorbed quickly. Potassium dihydrogen phosphate plus urea, especially when the absorption capacity of crop roots is limited, the effect is more obvious. Can also prevent excessive nitrogen fertilizer, resulting in plant nutrition growth too prosperous, the phenomenon of late ripening.
3. Application method of potassium dihydrogen phosphate + urea on different crops
(1) Grapes, kiwi fruit, dragon fruit, apple, pear, citrus and other fruit trees
Generally in the fruit tree after the flower set, the fruit tree spray drying potassium dihydrogen phosphate and urea, the fruit tree nutrition consumption can be timely supplemented, reduce the physiological fruit loss caused by nutritional deficiency, in the fruit expansion period and coloring period can be appropriately supplemented, the general concentration is 0.2-0.3%.
After xie hua, usable phosphate dihydrogen potassium 50 grams + urea 100 grams, add water 20 kilograms to undertake spray, can complement the nutrient that fruit development needs quickly, be helpful for protecting flower to protect fruit and fruit to expand.
(2) Tomatoes, peppers, loofah, eggplant, beans and other vegetables
In flowering and fruiting period, usable urea 50 ~ 100 grams + phosphoric acid 2 hydrogen potassium 50 grams, add water 20 kilograms spray, can supplement the nutrition that fruit development needs quickly, reduce falling flower falling fruit, promote fruit puffiness, prevent plantlet premature senescence, improve yield.
(3) Wheat, corn, rice and other crops
In the booting stage and filling stage of gramineous plants, due to vigorous reproductive growth, there are many nutrients needed, and at this time the root system of the plant is poor in the ability to absorb nutrients in the soil, making the leaves turn green and yellow, affecting the photosynthesis of the leaves, thus increasing the number of empty match grains, resulting in reduced production. Foliar spraying with 100 g urea + 100 g potassium dihydrogen phosphate + 20 kg water per mu could delay leaf senescence and significantly increase yield and improve quality.
(1) Do not spray in hot weather or rain before, so as not to burn seedlings or loss of fertilizer. Spraying time should be carried out in the morning or afternoon every day. After spraying, spray again every 7-10 days.
(2) When spraying cereal crops or crops with smooth leaves, 0.1% adhesive should be added (such as washing powder and cleaning). Otherwise, the effect is not ideal.
(3) Urea for spraying, the content of biuret should not be higher than 0.5%, high content is easy to damage the leaf.
(4) Different types of crops require different concentrations of urea solution spraying. General cereal crops require 0.5-1% spraying concentration, and the concentration is lower when spraying during flowering. Leaf vegetables and cucumbers were sprayed at a concentration of 0.5%. Fruit trees such as apples, pears and grapes should be 0.5%. 0.3% is appropriate for tomatoes.
(5) At present, there are more fake and shoddy potassium dihydrogen phosphate in the market. Farmers must pay attention to distinguish and buy pure products.
Tempu water soluble fertilizer, focus on doing good fertilizer!