外文翻譯--節(jié)水灌溉-全文預(yù)覽
【正文】 15% to 20%, they do not specifically facilities. Irrigation Sprinkler to spray through the air, due to the pressure of the monly used pressure aqueduct. In general, its obvious advantages irrigation uniformity, less of farmland, save manpower, strong adaptability to the terrain. The main disadvantage is influenced by wind, high investment in equipment. More in our country are the following: fixed pipe sprinkler, the semimobile pipeline sprinkler irrigation, a rolling shift sprinkler manifold, when the needle irrigation machine, a large pan spray irrigation machine, grain irrigation machine in microirrigators units and so on. drip irrigation Irrigation water with a small plastic tube directly sent to the the Meike crop roots near the water drip out slowly by drippers, a sophisticated irrigation methods, only need water to irrigation can truly only irrigation crop Instead of filling the land. And can be a long time in the crop root zone moisture in the optimal state, so to save water and increase production. But its biggest drawback is the Dripper out flow orifice is small, the flow rate is low, so serious congestion problems. 2 Irrigation water must be carefully filtering and processing. At present, China has only noticed to prevent physical clogging equally serious clogging the biological and chemical clogging problem has not been taken seriously enough. The main way of drip irrigation: fixedground drip irrigation, semifixedground drip irrigation. Membrane under irrigation, drip irrigation and other underground. irrigation Some places called mist irrigation, and drip irrigation similar too easy just to overe the Dripper disadvantage of clogging the drippers to micro sprinklers, microsprinkler flow orifice large, large number of traffic flow rate faster Unlike drippers so easy to plug, but the traffic has increased, capillary accordingly should bold some 1 to 2 micro sprinklers installed in every crop or tree usually can meet the needs of irrigation. Micro nozzle still clogged filtration problems, and therefore should be given adequate attention, the cost per hectare is similar to fixeddrip irrigation. Gradually replaced by drip irrigation micro sprinkler irrigation in a foreign country. Especially suitable for irrigated orchards. subsurface irrigation Similar to the subsurface irrigation and underground drip, just the Dripper all buried in the underground seepage head instead, the seepage head of water Unlike drippers as drop by drop outflow, but slowly seepage, such seepage head is not easy soil particles and root blockage. Recently introdu
畢業(yè)設(shè)計(jì)相關(guān)推薦
鄂ICP備17016276號(hào)-1