Seedling nutrition characteristics of spring crops
The nutrient requirements of spring crops at seedling stage are not large, but the nutrient concentration in the seedling stage is high, which requires strong soil fertility. Not only nitrogen, phosphorus, potassium, but also medium and trace elements, especially boron, zinc, calcium, sulfur, etc. are needed. However, the root development of crops is weak, and the ability to absorb fertilizer and water is poor. In the north, especially in the northeast, the spring temperature is low. When sowing corn or soybeans, the soil temperature is low, and the soil's own nutrient release is slow and may not be available. While the demand for nutrients for spring crops such as corn and soybeans is small, it is sensitive and strict, so it is necessary to supply less and better nutrition.
The seedling stage is the critical period of phosphorus nutrition, and the requirement for phosphate fertilizer is particularly high. At this time, if the phosphorus supply is slightly insufficient, the symptoms of phosphorus deficiency are likely to occur and affect the later yield. For example, purple leaf symptoms appear in the 3 leaf stage of corn. If the phosphate fertilizer is applied after the seedling period, it is difficult to make up for the loss caused by the deficiency at that time. In addition to phosphorus, seedlings are also sensitive to trace elements such as boron, zinc, sulfur, calcium, etc., to ensure the timely supply of these nutrients, can improve the ability of seedlings to resist drought and cold, and achieve the purpose of cultivating strong seedlings. Therefore, when planting corn and soybeans on soils that are not too fertile or do not apply organic fertilizers all the year round, in addition to deep application of base fertilizers, it is also necessary to combine the seeding and skillful application of fine fertilizers, which is already a cultivation of strong seedlings and an increase in yield. The proven technology is effective.
Fertilizer application technique
Fertilizer is a fertilization method in which a small amount of fertilizer is applied to the vicinity of the seed at the time of sowing. The role of seed fertilizer is to ensure that the spring crops are seedlings and seedlings, the amount of seed fertilizers can not be more, the proportion of nutrients is mainly phosphorus, and a small amount of nitrogen is used. The commonly used seed fertilizer is diammonium phosphate. The number of kinds of fertilizer, while small, can play a role in skillfully deflected the question.
The key to the application of seed fertilizer is to pay attention to the fertilization position in addition to the appropriate amount. A small amount of fertilizer should be applied 3 to 5 cm below the seed. Avoid placing the fertilizer close to the seed. Otherwise, even if the quantity is appropriate, the problem of burning seedling may occur. . Under the conditions of mechanical sowing, the seeds and fertilizers should be sown separately from the two reserve tanks and the two lower tube so that the fertilizer and the seeds are not on the same plane to ensure safe emergence.
Not all nitrogen fertilizer varieties are suitable for seed fertilizers. It is necessary to strictly control the nitrogen application rate of seed fertilizers and to select nitrogen fertilizer varieties. Elemental nitrogen fertilizer and ammonium sulfate are suitable for seed fertilizer, while ammonium bicarbonate, ammonium chloride, ammonium nitrate and urea are not suitable. In recent years, the lessons of burning seedlings caused by improper application of fertilizers in various places are worth learning. For example, the use of high-tower high-nitrogen compound fertilizer as a seed fertilizer, where the amount is large (more than 10 kg / acre) and the fertilizer is not deep into the soil, there are different degrees of inhibition of seedling growth. The compound fertilizer is better to use the diammonium phosphate as the seed fertilizer, and the seedling is safe and strong in the seedling stage.
Fertilizer application route
A large number of elemental fertilizers use soil as the main route, while trace elements can be soaked or seeded. For example, in the prevention and correction of the formation of zinc deficiency in rice deficiency, the South generally passes the soil through calcium phosphate or calcium magnesium phosphate fertilizer. However, in the rice seedling stage, the prevention and correction of the dead seedling caused by zinc deficiency is followed by seed dressing or soaking with 0.1% zinc sulphate solution. For example, soybean is sensitive to molybdenum deficiency, less molybdenum nodules, less activity, and no nitrogen fixation. The seedlings are not strong. The application of molybdenum in fertilizers is as follows: 2 g of ammonium molybdate per kg of seed, first dissolved with a small amount of water, and formulated into 2% to 3% solution of water, sprayed on the seeds with a sprayer, and stirred while spraying. Not too much, so as to avoid wrinkling of the seed coat and causing rotten seeds. After mixing, the seeds can be dried to be sown.
In short, the principle of application of seed fertilizer in spring-sown crops is the combination of a large number of elemental fertilizers and trace element fertilizers to achieve precise application and accurate position.
Author: Cao Yiping (The author is a senior consultant Sinochem fertilizer, China Agricultural University)
Source: Farmers Daily
Butt Weld fittings are also called Welded Pipe fittings. These welded fittings in carbon steel and stainless steel offer many advantages compared to threaded and socketweld fittings. The later are only available up to 4-inch nominal size whereas butt weld fittings are available in sizes from ½" to 102".
Stainless elbows are curved connecting pieces that join straight lengths of pipe, commonly at a 90° or 45° angle, allowing obstructions to be avoided in plumbing, ventilation, welding, and automotive applications.
We are manufacturer of Stainless steel Tees and supply high quality Stainless steel Tees in SUS304, SS316 grade offer you the best prices in the market.
Stainless steel reducer manufactured using superior grade raw materials.
Stainless steel reducers are used for connecting pipes of different diameters and find wide applications in various chemicals, construction industries, paper, cement & ship builders
Grades:
ï‚·Stainless Steel: ASTM, A403, WP304 / 304L / 304H / 316 / 316L / 317 / 317L / 321 / 310 / 347 / 904L
ï‚·Carbon Steel: ASTM, A234, WPB / A420, WPL3 / A420, WPL6 / MSS-SP-75, WPHY 42 / 46 / 52 / 56 / 60 / 65 / 70
ï‚·Alloy Steel: ASTM A234 WP1 / WP5 / WP9 / WP11 / WP22 / WP91
ï‚·Other Metals offered for making butt weld pipe fittings: Monel, Nickle, Inconel, Hastelloy, Copper, Brass, Titanium
ASTM A312, ASTM A351, A234 WPB, ASTM A197, A403 316L Pipe Fitting, A403 304/304L Elbow, 316/316L Pipe Fitting
Shijiazhuang Bang dong Pipeline Technology Co,Ltd. , https://www.bd-pipefitting.com