1. When the crop is watered, the quantitative fertilizer is dissolved in the ditch and infiltrated into the soil around the root of the crop with the watering. This method wastes a lot of fertilizer, and is easy to leak and leak in the channel. In the deep layer that the roots of the crop cannot reach, it will also infiltrate part of the fertilizer and cause waste. The advantage is that it is simple to use, saves labor and time, and has a small amount of labor. This method can be used when the fertilizer source is sufficient, the area of ​​growing vegetables is large, and labor conflicts are prominent. It can be used as the preferred method of top dressing when large areas of vegetables have severe fat deficiency symptoms.
Second, after the crop is poured into water or after the rain, the soil is suitable for the soil, and when it is able to go to the field, the quantitative fertilizer is applied to the crop surface or the crop line. This method is also relatively simple, but there is still some fat loss in the fertilizer, especially ammonium bicarbonate is very volatile, can not be used; ammonium sulfate, urea and potassium sulfate can be applied, but only in the field is not convenient, crops need Use when the fertilizer is more urgent.
3. Buried in the crops, ditching and digging between the rows, applying the quantitative fertilizer, and then filling the soil. This method is less wasteful and economical, but it is labor-intensive, labor-intensive, and inconvenient to operate. Pay attention to safety when applying. The buried fertilizer ditch and pit should be more than 10 cm from the base of the crop stem. If it is too close to the root, It is easy to damage the root system. Due to the concentration of fertilizer and the high concentration, this method should not be used in the summer when crops are vigorously growing and water is needed, and it cannot be used in the critical period of crop water demand. Generally, in the winter idle season, when the labor force is sufficient and the amount of crop growth is small, this method can be used to gradually decompose the buried fertilizer and continuously supply the crop. However, in actual production, the peak of crop growth is often the peak of fertilizer demand. Therefore, the method of burying is often used at higher temperatures. In order to prevent negative effects, water must be watered after burying to reduce the concentration of fertilizer applied.
IV. Facility pursuit In recent years, with the development of vegetable production technology in protected areas, the matching drip irrigation technology has been widely used, and the fertilization method has been on the track of automation. The specific method of using the drip irrigation facility for topdressing is to install the fertilizer device at the water source into the drip irrigation main pipe, dissolve the chemical fertilizer in the fertilizer applicator, and insert the drip irrigation main pipe into the suction pipe filter of the fertilizer applicator, and the fertilizer can automatically enter the crop root system with the watering device. In the surrounding soil. Due to the mulching film, the fertilizer is almost non-volatile and has no loss. Although the fertilizer is concentrated, the concentration is small, so it is safe, labor-saving and labor-saving, and the effect is very good. This is a more scientific and highly promising method of topdressing, only to carry out strict film mulching, and must be equipped with matching drip irrigation and tap water equipment.
Fifth, the root dressing outside the top dressing is the foliar spray fertilizer. Facility Horticulture and cultivation of vegetables, because the environment created by man-made is more convenient to meet the requirements of crops on environmental conditions, vegetables show the characteristics of fast growth, high yield and many results. In addition to paying attention to timely topdressing in the management, it can also be combined with spraying, and the root dressing is repeated several times to supplement the nutrient deficiency of the crop. This method is a cost-effective fertilization method because it has less dosage and quick fertilizer efficiency, and can avoid the fixation of fertilizer by soil. It can be used in the case of obvious deficiency and root senescence in the late stage of crop growth, and it can show its effect. In addition to urea, potassium dihydrogen phosphate, potassium sulfate, potassium nitrate, compound fertilizer and other commonly used large amount of elemental fertilizers, in recent years, many manufacturers in various places have developed suitable for foliar application. A large number of elements plus trace elements or fertilizers containing a variety of amino acid ingredients, such as spray Shibao, plant protection, farm music and so on. However, it must be noted that the basic nutrients required for the growth and development of vegetables are mainly derived from the base fertilizer and other methods of topdressing fertilizers. The external top dressing can only be used as an auxiliary measure. Vegetable topdressing, careful grasp of vegetables, fattening, careful grasp of vegetables, fattening, careful grasp of vegetables, fattening, careful grasp
Graphite is an elemental element of elemental carbon. Each carbon atom is surrounded by three other carbon atoms (arranged in a honeycomb-like hexagon) to covalently bond to form a covalent molecule.
Since each carbon atom emits an electron, the electrons are free to move, so the graphite belongs to the conductor. Graphite is one of the softest minerals, and its use includes the manufacture of pencils and lubricants. Carbon is a non-metallic element that is located in the second periodic IVA family of the periodic table.
The specific use of graphite
1, for refractory materials, including refractory bricks, crucible, continuous casting powder, casting core, mold detergent and high temperature materials.
Magnesium carbon brick refractory material is the mid-60s, developed by the United States; in the world of magnesium carbon brick has been widely used in steel, and has become a traditional use of graphite. Aluminum carbon brick aluminum carbon refractories are mainly used for continuous casting, flat billet from the pipeline of the protective cover, underwater nozzle and oil well blasting tube.
Made of graphite and refractory crucible and its related products, such as crucible, curved neck bottles, plugs and nozzles, etc., with high fire resistance, low thermal expansion, melting metal process, by metal infiltration and erosion But also stable, good thermal shock stability at high temperatures and excellent thermal conductivity, so the artifacts and its related products are widely used in direct melting metal process.
2, steelmaking
Graphite and other impurity materials can be used as carbonizers in the steelmaking industry. Carburizing uses a wide range of carbonaceous materials, including artificial graphite, petroleum coke, metallurgical coke and Natural Graphite. In the world of steel-making carbon-based graphite is still one of the main uses of earth-like graphite.
3, for the conductive material
Graphite in the electrical industry is widely used as electrodes, brushes, carbon rods, carbon tubes, mercury rectifier cathode, graphite gaskets, telephone parts, TV picture tube coating and so on. Among them, Graphite Electrode is the most widely used, in the smelting of various alloy steel, ferroalloy, the extensive use of graphite electrodes. The graphite used in the electrical industry is very demanding on grain size and grade.
4, for wear and lubrication materials
Graphite is often used as a lubricant in the machinery industry. Lubricants are often not used in high-speed, high-temperature, high-pressure conditions, and graphite wear-resistant materials can be 200 ℃ a 2000 ℃ temperature and at a high sliding speed (loom / s) without lubricating oil work. Many of the equipment that transport corrosive media, widely used graphite materials made of piston rings, seals and bearings, they run, do not need to add lubricants, graphite milk is also a lot of metal processing (wire drawing, pull tube) when the good lubricant.
5, for corrosion-resistant materials
Graphite has good chemical stability. After special processing of graphite, with corrosion resistance, good thermal conductivity, low permeability and other characteristics, and widely used in the production of heat exchangers, reaction tank, condensate, combustion tower, absorption tower, cooler, heater, filter Pumps and other equipment. These equipment for the petrochemical, hydrometallurgical, acid and alkali production, synthetic fiber, paper and other industrial sectors, can save a lot of metal materials.
6, for the atomic energy industry and the defense industry
Graphite has a good neutron deceleration performance, the earliest as a slowdown agent for atomic reactors, "uranium-graphite" reactor is currently used more of an atomic reactor. As the power of the atomic energy reactor in the slowdown material should have a high melting point, stable, corrosion-resistant properties, graphite can meet the above requirements.
7, for anti-scaling anti-rust materials.
Graphite can prevent boiler fouling. Tests have shown that adding a certain amount of Graphite Powder to the water prevents the surface of the boiler from scaling. In addition, graphite coated with metal chimneys, roofs, bridges, pipes can be anti-corrosion and rust.
8, graphite new use
1) Flexible graphite products. Flexible graphite, also known as Expanded Graphite, is the 1970s developed a new graphite products. 1971 US research success of flexible graphite sealing material, to solve the problem of atomic valve leakage, followed by Germany, Japan, France also began to develop production. In addition to this product has the characteristics of natural graphite, but also has a special flexibility and flexibility. Therefore, it is an ideal sealing material, widely used in petrochemical, atomic and other industrial fields, the international market demand growth year after year.
2) the production of semi-metallic friction materials. Since the 1970s, clutches and automatic liners have been widely used semi-metallic friction materials. Semi-metallic friction material is the graphite and metal powder, steel fiber, clay powder made of synthetic resin. These automatic lining can be used for high-speed equipment such as aircraft, trucks and off-road vehicles, and clutch pads.
Graphite
Carbon Graphite,Graphite Mineral,Monolithic Graphene,Graphite Crystal
Fengcheng Ruixing Carbon Products Co., Ltd , http://www.lnfcrxts.com