The globe valve is used to cut off the flow of the medium. The globe valve is suitable for frequently opened occasions. The sealing parts of the globe valve are the disc and the valve seat. In order to make the globe valve close tightly, the mating surface of the disc and the valve seat should be grinding or using gaskets. The sealing surface can also be inset with bronze, stainless steel and other corrosion-resistant and wear-resistant materials. The disc and stem of the globe valve are connected with each other, so that the disc and stem are closely fitted. The lifting of the disc of the globe valve is generally controlled by the stem. The upper part of the stem of the globe valve is the handwheel, and the middle part is the thread and packing sealing section. The role of the packing is to prevent the internal medium of the valve body from leaking along the stem. Globe Valve,Globe Control Valve,Globe Valve Types,Flanged Globe Valve WUXI KVC-VALVE , https://www.kvgatevalve.com
Realize four major unifications: water saving, fertilizer saving, high yield, and simplification
Do a good job in eight technologies: soil, earthworms, earthworms, fertilizer, dense, quality, species, water
(1) Choosing the right soil - "soil"
The suitable soil for water-saving and high-yield cultivation is sand soil, light soil and medium soil, and the soil fertility is medium or medium. Sand soil has less water storage capacity, which is not suitable; although the clay water storage capacity is large, the effective water supply is small, and the evaporation water consumption is more, the effective water consumption is less. Therefore, in practice, an additional irrigation is required.
(2) Bottom water regulates soil water storage, and sufficient seeding - "墒"
By pouring the bottom water before sowing, the water content of the 2 m soil reaches more than 90% of the field water holding capacity. In the normal precipitation year, every 667 square meters (1 mu) needs to be filled with 50 cubic meters. In September, the rainfall should be more than 50 cubic meters when it is more than normal. In September, the rainfall is less than 50 cubic meters when it is less than normal. It is necessary to break the traditional concept of “only more irrigation can make more grainâ€, establish a new concept based on the use of soil water, and store enough soil water before sowing. Wheat can reduce irrigation water by 50-100 cubic meters in a lifetime, due to the use of soil. Water, after the wheat harvest, the soil has a large empty storage capacity, which can accommodate more summer precipitation and reduce rainwater loss during the flood season.
(3) After the broadcast, the soil conservation guarantee - "æš„"
After the wheat is sown in the ditch, the ridges are not repressed, and the surface bauxite is covered in the long winter, winter and early spring, which can play a good role in ensuring the mites.
(4) All fertilizer base application, no top dressing - "fat"
Master the principle of “limited nitrogen, stable phosphorus, potassium and zinc, organic and inorganic combinationâ€. All fertilizers are used as base fertilizer to promote root development and nutrient absorption in the early stage, which can compensate for the disadvantage of the early soil and the middle and upper middle soil water deficits. Influence, and create conditions for the use of lower soil moisture in the later period. At the same time, it can simplify field operations, reduce nitrogen fertilizer losses, and improve fertilizer utilization.
Generally speaking, under medium soil fertility conditions, the production target of 450-550 kg per 667 square meters (1 mu) is achieved, and 1.5~2.0 cubic meters of organic fertilizer, 15 kg of diammonium phosphate, 15 kg of urea, and potassium sulfate are required. 10 kg, 1 kg of zinc sulfate.
(5) Appropriate late sowing, increase density, and keep seedlings stable - "tight"
Early broadcast on October 5, high temperature, large evaporation, no more water consumption before winter, and summer corn can not be fully mature, there are disadvantages and disadvantages; late October after October 20, no water consumption before winter, but root system It is difficult to deepen, and the heading period is postponed, which is more harmful than good. Therefore, water-saving cultivation should be properly broadcasted at night, suitable for the broadcast period of October 10-20. Not only can it reduce the water consumption before winter, but also provide time for the full maturity of summer corn, so that summer corn can increase production. Late sowing should increase the amount of seeding, suitable for basic seedlings of 350,000 to 500,000 per 667 square meters (on October 10, the sowing date, 350,000 per 667 square meters; on October 20, the sowing period, 500,000 per 667 square meters). High density can compensate for the adverse effects of soil water deficit on the number of spikes before the jointing, and increase the number of seed roots, improve the distribution of roots, and improve the utilization of deep soil water.
(6) Ensuring the quality of land preparation and sowing - "quality"
Due to the basic seedlings, the uniformity of seedling distribution is particularly important, ensuring that the quality of land preparation and sowing is the key link for water-saving and high-yield cultivation. In order to reduce the shrinking seedlings, reduce the rate of weak plants, and improve the uniformity of the ear, it is required to: (1) select the seeds to make the grain size uniform and strictly eliminate the broken granules. (2) Deep ploughing and ploughing, leveling the soil surface: It is necessary to plow the soil, bury the root hoe and straw, and plow the depth of 15~20 cm. After ploughing, strictly smash the ground, crush and smash the ground, so that the plough layer can be realized. The soil is flat. Cultivate homework, time obeys quality. (3) Strictly control the sowing, so as to ensure that the sowing depth is consistent (deep 3~5 cm) and the seeds are evenly distributed. According to the basic seedling requirements and seed germination rate, the seeding amount is calculated, and the row spacing is 15~20 cm. Regardless of the machine broadcast and the sowing, the seed load should be strictly adjusted before the sowing. The broadcast can take the in-line replay hungry mode.
(7) Choosing the right variety - "species"
In order to achieve high yield under water-saving conditions, it is necessary to use medium-grained high-yield and drought-tolerant varieties with early maturity, large amount of ear-capacity, large number of grains per panicle, stable and fast filling. Such as: 95021, Lumai 21, 8871-3, Jinan 17, and so on.
The maturity period can shorten the post-growth time, reduce the water consumption, avoid or reduce the dry hot wind hazard; the large amount of the ear can be used to implement the late sowing and large-batch technology, and increase the yield by seedlings and spikes. It is difficult for large panicle varieties to exert the ear weight potential. The number of grains per panicle is stable and stable, so that it can adapt to the environment of soil water deficit in the upper layer before and after jointing, which delays the watering time in spring. The grain filling is fast and the seeding time is short, which can alleviate the high temperature and drought in the later stage. The adverse effects of the upper soil deficit on the grain weight enable the full potential of the variety.
(8) Spring water is called late, suitable for the right amount - "water"
In the spring one-water system, the optimum irrigation period is jointing (medicine interval) to booting stage (four-part period). In this stage, according to the seedlings and lyrics, it should be as late as possible. The non-dry hot wind type was the highest in the jointing stage, and the dry-hot wind type was the highest in the booting stage. In the spring two-water system, the optimum irrigation period is one-water jointing and watering. The amount of irrigation is 50 cubic meters per time.
China's North China region is in short supply of water, with little annual rainfall, and is mainly concentrated in the summer. The wheat growing season is windy and rainy, and the water consumption is large. 70%~80% of the high-yield wheat field water needs to be supplemented by irrigation, and the wheat is usually filled with water during the whole life. ~6 times, the total irrigation volume is 3000~3750 cubic meters/ha, and many areas are mainly maintained by over-exploitation of groundwater, which not only exacerbates water stress, but also under full irrigation, the soil vacated after wheat harvest is small and can not accommodate summer. Loss of soil nutrients and pollution of groundwater. In recent years, China Agricultural University and other units have studied and promoted the application of winter wheat water-saving, high-yield and high-yield cultivation techniques, and it is introduced to everyone:
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