1、中文5100字，3000英文单词，1.7万英文字符外文翻译（原文） - 1 - WIRELESS NETWORK FOR IRRIGATION CONTROL AND SENSING Variations in plant water and nutrient demand and environmental regulations to protect water quality provide significant justification for site specific irrigation and fertigation systems. We have deve
2、loped wireless valve controllers that self assemble into a mesh network. Mesh networking means that controllers pass messages to extend the effective communication range without using high power radios. Solar energy is collected with a 200mW panel to operate each controller node without yearly batte
3、ry replacement. Nine nodes were tested in a mesh network, and each properly responded to commands. Measurements of battery voltage, solar panel voltage, enclosure temperature, and external sensors were transmitted every 10 min. Irrigation schedules were stored locally on each node and executed autom
4、atically. Schedules for each node were unique, based on the needs of the particular area being irrigated. Internal clock drift was an average 6.3s per day. Clock offset was removed using daily time stamps. One hop transmission range using 916MHz radios varied from 20.9 m with a whip antenna at groun
5、d level to 241.1m with a dipole antenna at 3 m. Node commands were acknowledged after an average of 2.7s per hop. Charge consumption was approximately 7.03mAh per day for the node circuit and 1 mAh per day for battery self discharge. The solar panel produced 26.0 to 81.3 mAh in direct sunlight and 6
6、.5 to 13.7mAh in shade. Node operation is expected to be continuous with occasional sunlight exposure. Soil moisture, pressure, temperature, and other environmental sensors will be used for feedback control and detection of problems. Such a network of intelligent valve controllers will allow growers
7、 in orchards, vineyards, nurseries, greenhouses, and landscapes to develop management practices that improve water and fertilizer use efficiency. Conventional irrigation management provides water and nutrients uniformly across an entire field and ignores the reality that demand varies due to d
8、ifferences in 外文翻译（原文） - 2 - soil, topology, and plant water and nutrient status. For site specific management, large plots are divided into several smaller management units based on variable site characteristics and each is provided individualized water and nutrient input to maximize profits
9、, crop yield, and water use efficiency, and lessen environmental impacts. The benefits of site specific management have been reported for many years. Matching nitrogen delivery with plant needs has increased fertilizer use efficiency and net returns in some field crops and reduced nitrate leac
10、hing in potato crop simulations . Variable rate application of granular fertilizer based on individual tree size in citrus reduced overall nitrogen application by 38% to 40% compared to conventional treatment. It seems logical that the benefits of variable rate granular fertilization would be seen f
11、or variable rate fertigation as well. Spatially variable management has also been shown to increase profits from corn and improve yield in potatoes and grain sorghum . Site specific irrigation has been most thoroughly tested in center pivot and linear move systems for field crops . Much
12、less development has occurred for fixed irrigation systems, which are used in high value permanent crops and commercial horticulture. Site specific technology for fixed irrigation would be applicable in orchards, vineyards, landscapes, nurseries, and greenhouses, each of which has unique management
13、challenges. The water and nutrient demand of trees, plants, and vines are impacted by variations in soil condition, elevation, or microclimate. When applied uniformly, water and fertilizer may leach in light textured soils and pool in heavy soils. Planting on steep slopes,as occurs with some vineyar
14、ds and orchards, creates difficulty in preventing runoff and maintaining irrigation uniformity due to pressure variations. Commercial nurseries and greenhouses contain many different varieties of ornamental plants in close proximity to one another and must deal with continually changing inventory an
15、d strict environmental regulations. A single valve typically controls water flow to many emitters, and if there are plants of differing size or water requirements, some will receive too much water, while others will receive too little.Irrigation control for landscapes in arid parts of the U.S. is al
16、so important 外文翻译（原文） - 3 - since a significant amount of water is used for public turf grass and ornamentals. Converting conventional fixed irrigation systems to allow site specific delivery of water and nutrients would create many small management units, each with a valve that must be indep
17、endently controlled. Additionally, each should have the capability to read in field sensors such as temperature and soil moisture, which are commonly used for closed loop irrigation control. Site specific control for fixed irrigation systems has been limited. Torre Neto et al. used latching solenoid
18、 valves to control two laterals per row in a citrus orchard. Each lateral uniformly irrigated half the trees in the row, which were grouped based on size . Miranda controlled water flow to individual laterals for potted plants based on soil moisture feedback. Coates et al. and Damas et al. designed
19、systems to control latching valves and read sensors for irrigation control. In each of these systems, wiring between valves, sensors, and controllers is expensive to install and is subject to damage by animals and machinery. Miranda et al. recognized this by developing solar powered, standalon
20、e irrigation controllers with soil moisture sensors. However, the system did not include any communication means for centralized aggregation of sensor data or remote monitoring and reprogramming. Wireless communication has been used to monitor in field sensors, although many use large batteries and
21、solar panels or still require hard wired valves for irrigation control. Recent low cost, low power wireless networking technology is well suited to replace wires as the communication medium in many agricultural applications . In this article, we describe the development of a solar powered, wir
22、eless network for site specific application of water, fertilizer, and agricultural chemicals using completely autonomous units with mesh networking capability for both sensing and valve control. Large or small valves can be used to allow management of multiple sprinklers or drip emitters, or individual plants or trees . Each valve was programmable with a unique schedule to match differing water and nutrient requirements and could be changed to accommodate replants, disease, growth, or seasonal changes. Data from electrical conductivity, pressure, soil moisture, or flow
