I. Selection of grass species Planting pastures should be based on the ecological conditions of the land, the length of time the pasture is growing, the type of species, yield, quality, and the variety of animals fed. It mainly considers the following three aspects: (1) Local natural conditions and land conditions The characteristics of pasture such as drought tolerance, cold-resistance, shade-resistance, and disease resistance are formed for many years under conditions of origin. Therefore, when selecting grass seed, it is necessary to consider whether the local natural conditions and land conditions are suitable for planting such pastures. If the differences are too large, they will often be dissatisfied with soil and water, have poor growth, have low yields, and even fail to plant. Under normal circumstances, lots of flat land, irrigation conditions and good soil quality are suitable for planting large-scale fertilizers and large-scale fertilizers, and they can obtain higher yields; hilly lands, mountainous lands, and infertile lands should have strong adaptability. Drought-tolerant and flood-tolerant varieties; saline-alkali lands should be selected for salt-tolerant varieties; between forests and fruit trees, plants with shorter plants and shade-tolerant varieties should be selected. (b) Variety Types There are many types of pastures. They include grasses, leguminosae, asteraceae, crucifers, coryllidae, cinerea, and sedges. The vast majority of pastures currently planted are legumes and grasses. Leguminous forage is a one-year or perennial herb, straight roots, stout roots, deep into the soil, roots often have nodules, can fix nitrogen in the air, both the role of land; legumes containing crude protein, calcium, carotene More, higher nutritional value, can replace some of the fine material, but some contain saponin, green feeding or grazing easily cause swelling disease; stems and leaves of legume grass are uneven drying, leaves easily fall off, modulation of hay more difficult, in addition Silage should not be used alone. It is best to mix silage with grasses. Grass forage is a one-year or perennial herb with fibrous roots. It has many growth points and strong grazing resistance. The dry speed of the stems and leaves of gramineous pastures is the same, and the leaves are not easy to fall off. It is suitable to modulate hay, contains more carbohydrates, and is suitable for silage. (3) Yield and quality of pasture In general, yield and quality are often not shared, which means that high-yield pastures are often palatability and have poor nutritional value, while high-nutrition and good-pacity grasses have low yields. This requires double consideration when selecting grass species. With the development of modern breeding techniques. There are more and more high-yield and high-quality varieties. It should be noted that the yield and nutrient content of various forage grasses are not fixed, and there are significant differences with different seed quality, climate, soil, fertilization, irrigation, and utilization patterns. Therefore, the use of the same type of pasture is not always the same. Second, the pre-planting field forage is the same as the crops, and intensive cultivation can achieve high yields. Most pasture seeds are very small, weak in the top soil, and grow slowly in the seedling stage. The soil preparation before planting is the key to good seedlings and seedlings. The main measures for land preparation before sowing are to turn and suppress. Under normal circumstances, the ripening can be used directly after sowing and splitting with a plough, and the uncultivated land or soil compacted plots must be deep-turned 20-25 cm deep with a tractor. If a mature farmyard manure is applied and phosphorus and potash are used, then better. After ploughing, pressure must be applied (using a disc harrow and a roller compactor) to chop large blocks of soil to make the topsoil compact. The soil layer is smooth and smooth, which will help preserve grasshoppers and create good soil conditions for sowing, seedlings, and growth. III. Seeding (I) Seeding Period The spring season with good water conditions or land with irrigation conditions can be sowed in spring. Otherwise, it is generally sown at the onset of summer rain, but it cannot be later than in early July to facilitate the safe wintering of seedlings. Generally speaking, it should be determined based on the comprehensive factors such as grass species, soil, and moisture. (2) Seed treatment The legume seed has a high hard seed rate. The seeds need to be treated before seeding so as to increase the germination rate. Rhizobium inoculation should also be carried out. Gramineous seeds need to be treated with awns. Hard seed treatment generally uses rice mill or stone grinding rub seeds, cut seed coat, conducive to water absorption; go awning can be used to mans mill or roller compactor. Rhizobium seed dressing refers to nodules in roots, for example legumes that have not been planted on legume plots. Legume seeding should be carried out before sowing, so that nodules can be formed early in seedlings and early formation of nitrogen fixation capacity. . The method is to purchase rhizobial seed dressing, but also to collect root nodules of the same type of grass, and crush and stir into the seeds after air-drying. It should be noted that the legumes of leguminous herbaceous rhizome can be divided into eight groups that can inoculate each other. Inoculation between different groups of pastures is ineffective. (3) Seed sowing methods can be used for seeding, sowing, sowing and transplanting. The seeding and broadcasting speed is faster, the seeding depth is even and the seedlings are neat, which facilitates field management such as cultivating, weeding and fertilizing. In the hill slopes where engineering measures are available, sowing methods can be used, such as bamboo shoots and fish scales, and grasses can also be used on steep slopes. Spreading is used when the grass is large, using a seed drill or an airplane. Transplanting seedlings generally applies to taller forage grasses and is available when the planting area is small or when there is sufficient manpower. (4) The sowing volume should be determined based on the biological characteristics of pasture, the use (grass or seed collection) of seed size, quality, soil fertility, land preparation quality, sowing time and climatic conditions during sowing. (e) The seeding depth should be such that the seeds come into contact with moist soil, and the soil will not evaporate after covering the soil. Since most grass seeds are small and the top soil is weak, the coverage should not be too deep, generally 2-3 cm is appropriate, and the following principles can be followed: the large seeds should be deep and the small seeds should be shallow; the loose soil should be deep, and the heavy soil should be shallow; The dry season should be deep and the water should be shallow; it should be deep in spring drought, and the summer rain season should be shallow. When the conditions are appropriate, shallow sowing is better, and the seedlings can be kept neat and tidy. IV. Field management After the sowing of grasses, they will enter the field management work, mainly including weeding, weeding, irrigation, fertilization, pest control, and cold protection. (1) Weeding: Forage grasses grow slowly and are often immersed in weeds. Weeding, shoveling, and hoeing can be used for weed control. Ning does not need to be late. Generally, weeds lose their competitiveness after mulching. (II) Irrigation: For grasses from tillering to flowering, leguminous plants need a large amount of water from flower buds to flowering, and this is the main irrigation period. Pastures that are cut many times a year should be irrigated promptly after each cutting; when the weather is heavy and the drought is severe, irrigation should be conducted. Before freezing, filling the frozen water once in winter is beneficial to the safe wintering of forage grass and to the green growth in the early spring of the second year. (3) Fertilization: In addition to the application of base fertilizer at the time of sowing, pasture should be fertilized after each cutting, and it can also be carried out in combination with cultivator and irrigation. Grass-based pastures are dominated by nitrogen fertilizers. Legume forages have nitrogen-fixing functions. In addition to applying a small amount of nitrogenous fertilizers during the seedling stage, phosphorus and potassium fertilizers should be used for the rest of the period. (IV) Pest control: Pastures are more resistant to pests and diseases, and fewer pests and diseases occur than field crops. The prevention and control methods follow the principle of â€œprevention as the mainstay and comprehensive prevention and controlâ€ and strengthen seed quarantine and agricultural control. (5) Protection against the cold: In some cold regions, some pasture varieties are difficult to winter, and they are protected from cold before entering winter. The main method is to plow with a ply stick before winter, so that the soil covers the roots of pasture, generally can achieve the effect of preventing frostbite. V. Timely cutting and storage of pasture Grass can be fed on a timely basis with green pasture, or dried hay and silage can be used in case of lack of winter and spring feed. Different grasses produce at different growth stages and their quality varies greatly. Taking alfalfa as an example, the content of crude protein and crude fiber in dry matter, the vegetative growth period was 26.1% and 17.2%, the budding period was 22.1% and 3.6%, and the flowering period was 18.2% and 18.5% of the end of the period were 12.3% and 40.6%. It can be seen that with the extension of the growth stage, the crude protein content gradually decreased, while the domestic animals did not absorb the digested crude fiber significantly. However, if the castration is too early, the yield is low. Therefore, it is necessary to determine the most appropriate period of castration. To determine the optimum cutting period, that is, not simply based on the yield, but also on the quality, but the two should be combined, must be based on the amount of nutrients within the unit area to determine. In general, leguminous pastures can obtain the highest nutrient content per unit area from flower buds to early flowering stages. At the same time, in terms of perennial forage, cutting is not only a product harvest but also a field management measure. Due to the appropriate cut time. Whether it is suitable or not has a great influence on the growth of pasture. The number of cuttings should be based on the biological characteristics of pasture, climate conditions in different regions, and the level of cultivation and management techniques. The last time before the winter can not be castrated too late, there must be sufficient regeneration time to allow plants to accumulate enough nutrients to improve the ability of the roots to resist cold and safely winter. Should generally be carried out 3-4 weeks before winter. The height of stubble must also vary according to pasture. If è‹œè“¿ èŒ¬ 4-5 cm is appropriate. In addition to the use of cultivated pastures, they are mainly used to prepare hay or silage for use in winter and spring. High-quality hay has high nutritional value, good palatability, and all kinds of livestock prefer eating. Storage of large amounts of hay can guarantee the nutritional needs of livestock in winter and spring. The dry speeds of stems and leaves of grasses are relatively uniform and relatively easy to make. The stems and leaves of leguminous pasture have different drying time. The leaves are drying fast and the stems are drying slowly. The leaves are often lost during the drying process, which reduces the nutritional value of hay. Drying hay should first consider the local climatic conditions, to select the sunny dry season. After the castration, it is leveled on the ground. After a sunny day, the leaves are withered and the water content is about 45-50%. The haystack is about 1 meter high. After 2-3 days, when the hay can be twisted into a straw rope, it is not When it is not cracked, it will drop to about 20% moisture content, and it can be transported back to the storage near the shed. However, at this time, the moisture content of the forage grass is unsafe, and it should be promptly ventilated and cooled in the wet weather. The drying process must avoid rain, mildew, to ensure the quality of hay. After stacking, special attention should be paid to the grasshopper not being infiltrated by water so that the hay rots and molds.
Slit Lamp Microscope
Ophthalmic Equipment Slit Lamp,Slit Lamp Microscope,Optical Slit Lamp
Medsinglong Medical Equipment Co., Ltd. , http://www.gzultrasound.com