文丘里差压式喷灌施肥装置的性能研究

本文主要介绍100PS－1型文丘里差压式施肥装置的工作原理、水力学性能、施肥罐内肥料浓度的变化规律及施肥均匀度的试验数据。通过对试验结果的研究分析,我们认为采用这种形式施肥装置是完全符合喷灌系统对施肥的要求的。     

From on-farm solid-set sprinkler irrigation design to collective irrigation network design in windy areas

In this paper, a contribution to the design of collective pressurised irrigation networks in solid-set sprinkler-irrigated windy areas is presented. The methodology is based on guaranteeing minimum on-farm performance, using a historical hourly wind speed database and a ballistic solid-set irrigation simulation model. The proposed method was applied to the Montesnegros Irrigation District (central Ebro basin, Spain). The district irrigates an area of 3493 ha using an on-demand schedule. The average wind speed in the area is 2.8 m s⁻¹. An analysis of district water records showed that farmers often reduce water demand when the wind speed is high, but their irrigation decision making is limited by the capacity of the irrigation network and by the unpredictable character of local winds. Simulations were performed for 11 irrigation seasons, 2 triangular sprinkler spacings (18 m × 18 m and 18 m × 15 m), and 2 sprinkler models. The percentage of monthly suitable time for irrigation was determined for four management strategies. The first one was based on a wind speed threshold (3 m s⁻¹), while the other three were based on three levels (standard, relaxed and restrictive) of two irrigation performance parameters: the Christiansen Uniformity Coefficient (CU) and the Wind Drift and Evaporation Losses (WDEL). The standard strategy classified the time as suitable for irrigation when CU ≥ 84% and WDEL ≤ 20%. The thresholds limits of the irrigation parameters for the relaxed strategy were CU ≥ 80% and WDEL ≤ 25%. Finally, the restrictive strategy used thresholds of CU ≥ 90% and WDEL ≤ 15%. The suitable time for the first strategy (56%) was always lower than for the standard and the relaxed strategies (with respective average values of 75 and 86%), and higher than for the restrictive strategy (30%). In order to design the collective network, the hydrant operating time was equalled to the suitable time for irrigation. The differences in the cost of the collective network plus the on-farm equipment were particularly relevant between the restrictive strategy and the other three. Differences in suitable operating time were clear between sprinkler spacings, and less evident between sprinkler models. The application of the proposed methodology may be limited by the availability of historical wind speed records and CU estimates for different combinations of sprinkler models, sprinkler spacings and wind speed.     

PG99S智能型喷灌机的调试及维护

在蔬菜、花卉的工厂化育苗生产中,准确控制肥水的浓度和喷洒的均匀性显得尤为重要,而喷灌设备作为智能型连栋育苗温室的主要浇灌设备,被广泛应用于现代化育苗温室中。该设备自动作业,水量控制精准。本文就PG99S型智能喷灌机介绍其调试方法和故障维修。     

基于2DVD的非旋转折射式喷头水滴直径分布规律

采用基于三维视频粒子测量原理的视频雨滴谱仪(Two-dimensional video disdrometer,2DVD)对喷灌机中常用的Nelson D3000型喷头在多个工作压力下水滴直径沿射程的分布进行了测量,分析了水滴直径沿射程的变化趋势及水滴速度、水滴角度与水滴直径之间的关系。结果表明:水滴直径与射程符合指数函数关系,在距离喷头相同测点处,水滴直径随工作压力的升高而减小,而射程末端的水滴直径随着压力的升高而增大;水滴速度随水滴直径增加而增大,两者呈对数关系;水滴落地时与地面夹角(简称水滴角度)随水滴直径增加呈减小趋势,水滴直径小于1.0 mm时,50、100、150和200 kPa工作压力下,与地面夹角为90°的水滴个数占总水滴数的比值分别为90.46%、84.46%、89.91%和89.15%,其余水滴与地面夹角在30°~89°之间,水滴直径在1.0~2.25 mm范围内,水滴角度随水滴直径的增加迅速减小,水滴直径大于2.25 mm时减小趋势变缓,4个工作压力下最大直径水滴落地时与地面夹角平均值为45°;工作压力对于水滴直径与速度、水滴直径与角度之间的关系影响较小。     

北京地区冬小麦田渗灌高产节水技术研究初报

研究了不同灌溉方式下冬小麦田间土壤水分变化特点及对小麦产量形成的影响。结果表明,渗灌浇根不浇地,冬小麦全生育期渗灌田0～20cm土壤表层含水量较低,比喷灌0～20cm土层土壤水分消耗小,比20～120cm土层土壤水分消耗多;2种灌溉方式120cm以下土层土壤含水量为冬小麦利用较少。渗灌比喷灌增产11.6%,比少灌增产17.6%,比喷灌节水57.1%,其水分利用效率为喷灌的1.35倍。     

地埋式自动伸缩喷灌系统施工技术研究

地埋式自动伸缩喷灌设备作为一种达到国际领先水平的新型高效节水灌溉设备具有较为显著地优势,笔者以宁夏旱作节水高效农业科技园区内建设的地埋式自动伸缩喷灌苜蓿种植示范区为例,从现场勘测、施工方案设计、现场放线与土方开挖、管道铺设安装与压力测试、喷头安装与管沟回填、检查井与泄水井建设、首部过滤系统安装、水源动力系统建设等10个方面总结归纳了该系统的施工技术及其注意事项,为现有喷灌系统新建与改建及田间高效节水灌溉工程的建设提供给指导.     

潜水电泵在坡地喷灌工程中的应用前景

本文在分析南方坡地灌溉工程特点的基础上，阐述了坡地喷灌工程选用潜水电泵的优势，并通过一个典型喷灌工程不同泵型及泵站设计方案的对比，探讨了潜水电 泵在坡地喷灌工程应用的可行性及其有待解决的技术问题。     

Over-canopy saline sprinkler irrigation of grapevines during different growth stages

Wetting plant foliage with saline irrigation increases the uptake of toxic ions Na⁺ and Cl⁻. Over three consecutive seasons, Colombard vines grafted on Ramsey rootstock were irrigated with saline water (EC 3.5 dS/m) by over-canopy sprinklers during any one of the first three of the four annual growth stages: bud burst to full bloom (treatment BB-FB), full bloom to veraison (treatment FB-V), and veraison to harvest (treatment V-H). At other times, vines received non-saline water (EC 0.5 dS/m) as did the control. Seasonal average soil salinities remained relatively constant over the trial. In contrast, the concentrations of Na⁺ and Cl⁻ in one-year old wood and grape juice more than doubled. In treatments FB-V and V-H the average yield over the three seasons was reduced by up to 15%. Results were compared with those obtained in an earlier study which was undertaken in the same vineyard with the same treatments applied via dripper. With drippers, the maximum reduction in the average yield over three seasons was 2%. Saline sprinkling caused rises in Na⁺ and Cl⁻ concentrations of fruit, leaf lamina and one-year-old wood that were at least 7-fold, 5-fold and 2-fold greater, respectively, than the rises caused by application of the same treatments with drip. Progressive seasonal rises in the concentrations of Na⁺ and Cl⁻ in these tissues were due in part to carryover of salt added in previous seasons; with saline sprinkling the magnitude of these carryovers was 4-fold greater than those with saline drip irrigation. With saline water, vignerons can reduce losses by using irrigation systems which do not wet the foliage.     

低压条件下PY115型摇臂式喷头水力性能试验

针对喷头在低压条件下工作时水力性能较差的问题,提出采用异形喷嘴降低水滴打击强度并改善喷洒均匀性的方法.选取PY115型摇臂式喷头为研究对象,设计了3套改进喷嘴的方案,在出口喷嘴上增加了1、2、3个凹槽,凹槽的尺寸均为宽0.5 mm,高0.3 mm,位置分别在出口喷嘴下方和左右两侧.在工作压力为200 kPa下进行了试验测量,同时在正方形组合间距为13～18 m时,采用Matlab语言编制程序对其进行了仿真计算.试验和计算结果表明:在低压条件工作时,随着凹槽数量的增多,流量增大,射程缩短8.1％ ～9.4％,末端水滴直径降低系数为2.9％ ～ 6.8％,平均喷灌强度增大并均符合规范要求.增加凹槽有利于提高组合均匀系数,出口喷嘴增加3个凹槽时效果最佳,组合均匀系数最高超过90％,证明了所设计异形喷嘴方案的可行性.     

野云沟万亩自压喷灌工程供水成本及水费标准的分析

本文利用工程实际资料,对万亩自压喷灌工程供水成本及水费标准进行了分析讨论。并提出现阶段水费计收标准以及加强工程经营管理、降低供水成本、提高喷灌效益的初步意见。