Trench irrigation and border irrigation play a leading role, and seepage control reform becomes the key.
In California, more than 60% of agricultural irrigation adopts surface irrigation technology, which mainly refers to furrow irrigation and border irrigation improved and integrated by the latest modern scientific and technological achievements.
Ditch irrigation is the main part of local surface irrigation, accounting for more than 70% of surface irrigation, and is mainly used for fruit trees and intercropping crops such as cotton, peanuts and vegetables. Irrigation equipment supporting furrow irrigation mainly includes multi-port water supply plugs, multi-outlet water pipes and siphon pipes. The water plug is exposed to the ground for 30-40cm, and several small gate outlets, up to eight, are evenly arranged around it. Each outlet has a small water output, corresponding to one irrigation canal respectively, and eight irrigation canals can be irrigated at the same time. Multi-outlet water pipes are aluminum alloy earth moving pipes, and small gates are arranged at the same distance from the irrigation canal. During irrigation, one or more gates can be opened for irrigation or irrigation by turns according to the water supply or needs.
Border irrigation is mainly used for densely planted crops (such as wheat) in the field, mainly distributed on both sides of rivers with relatively rich water sources or in areas with rich groundwater. The width of the boundary is about10m, and the length is about 200m. Irrigation adopts large flow and rapid propulsion. Each border is equipped with a water supply plug, and one border is irrigated at a time. The border field has undergone strict laser leveling, and its specifications are determined according to the situation of farms, crops and water sources. Therefore, it also saves water.
Whether it is furrow irrigation or border irrigation, most of them use pipelines to deliver water. Water is directly sent to the ditch through the pipeline, and even in the gravity irrigation area, the water loss is quite small in the process of water delivery. Through laser leveling in the field, pulse irrigation, tail water recovery and other technologies, irrigation uniformity is very high, water flow infiltration is uniform, and irrigation efficiency is improved. Seepage prevention, field improvement and corresponding supporting equipment constitute the three core contents of surface irrigation water saving in the United States.
Various forms of sprinkler irrigation, drip irrigation and strict water quality filtration
There are many forms of sprinkler irrigation in California, USA, such as needle type, rolling type, translation type, coiled type and bracket type. For example, most lawn plantations in California are mainly translational, while most field crops are time needle, translational or coiled. Among them, stent sprinkler irrigation, that is, fixed or semi-fixed sprinkler irrigation, is the most serialized. As the name implies, fixed sprinkler irrigation refers to the form of sprinkler irrigation that is placed in the field all the year round from the support to the sprinkler and remains motionless, and is equipped with corresponding farming machinery. It is unique in the connection between the border irrigation support bar and the water pipeline, as well as the design of the pipe and pipe fittings of the sprinkler. The accurate title of semi-fixed sprinkler irrigation should be "seasonal fixed sprinkler irrigation", which means to put it away during farming and put it in the ground after farming until harvest.
In addition, small sprinkler irrigation can be seen everywhere in California. This is a form between micro-sprinkler irrigation and sprinkler irrigation, with less investment and strong applicability. It is mainly used for low-density crops, such as vegetables and strawberries. Micro-sprinkler irrigation is mainly used for fruit trees and environmental greening.