基于作物蒸散量模型的新型滑盖温室智能灌溉系统设计

为了解决温室大棚的精准灌溉问题,设计一套基于修正后的Penman-Monteith方程计算作物灌溉量的智能灌溉系统。系统选用光照传感器、温湿度传感器,土壤水分传感器采集温室大棚环境参数,由数据采集器传送至上位机,利用灌溉模型计算出作物不同生长期的蒸散量,并将蒸散量换算成灌溉量,通过上位机发出灌溉命令,控制恒压变频控制器的运行和电磁阀的启闭。远程操作系统采用GPRS与基地控制系统连接,实现参数设置、实时数据显示和查询以及控制灌溉模式。试验结果表明,该系统能够实现精准灌溉自动控制,系统稳定可靠,操作方便,适用于温室大棚精准灌溉。     

大棚温室双上孔软管滴灌新技术

软管滴灌是专为大棚温室内的生产而开发的节水增产灌溉技术,属于局部灌溉,使地面局部湿润,无积水且水分蒸发较少。它利用双上孔滴灌带,直接铺设在作物畦面上灌水,能为棚内作物生长提供良好的环境。为了配合该项技术的发展,现将大棚温室双上孔软管滴灌新技术介绍如下:     

大棚温室软管滴灌法

软管滴灌是专为大棚温室生产而开发的节水增产灌溉技术,属于局部灌溉,使地面局部湿润。无积水且水气蒸发较少。它利用双上孔滴灌带,直接铺设在作物畦面上灌水,能为棚内作物生长提供良好的环境。     

大棚温室软管滴灌法

软管滴灌是专为大棚温室生产而开发的节水增产灌溉技术，属于局部灌溉，使地面局部湿润，无积水且水汽蒸发较少。它利用双上孔滴灌带，直接铺设在作物畦面上灌水，能为棚内作物生长提供良好的环境。下面将双上软管滴灌新技术介绍如下：     

温室大棚灌溉技术的探讨

分析了温室大棚蔬菜生产时对湿度的要求,提出了温室大棚内的空气湿度的调控方法,对比了温室大棚的几种灌溉方法.重点对温室大棚微灌技术作出分析,讨论了温室大棚膜下滴灌、重力滴灌、渗水灌溉技术,并且提出温室大棚利用雨水资源的方法以及灌水器堵塞的防治方法.     

物联网技术视角下温室蔬菜智能灌溉控制系统分析

本项目提出了一种基于物联网技术的温室蔬菜智能灌溉控制系统,此系统可以通过无线传感器智能采集温室内空气温湿度、土壤温湿度、二氧化碳浓度、光照强度的环境参数信息,并可以通过无线传输协议实现各类环境参数的自动化获取、传输以及执行控制。实践结果表明,温室蔬菜智能灌溉控制系统可以根据土壤温湿度情况,自动控制滴灌设备进行自动化滴灌,相对于常规滴灌设备来说,温室蔬菜智能灌溉控制系统可以达到15%～20%的节水效果。     

设施农业中de微灌机械化技术

山东省龙口市以温室大棚为主要形式的设施农业发展迅速,各种温室大棚达3万个。葡萄、蔬菜、草莓、花卉、果树等优质高值的设施农业种植面积达0.3万hm~2。近年,龙口市农机部门针对温室大棚发展快、灌溉用水量大、水资源贫乏的特点,引进以色列和韩国微灌机械化设备,开展了温室葡萄、蔬菜、草莓滴灌,花卉微喷灌,果树小管出流等微灌机械化技术试验示范。     

基于双作物系数法的新疆覆膜滴灌夏玉米蒸散量估算

为评估双作物系数法计算干旱区部分覆膜滴灌条件下夏玉米蒸散量的可靠性,于2016—2017年在新疆阿克苏地区开展了夏玉米蒸散量测坑试验研究,试验根据定灌水周期（W1、W2、W3）和变灌水周期（W4、W5）共设置5个处理,并分别采用稳定碳同位素法和水量平衡法,对双作物系数模型计算的夏玉米蒸腾量和蒸散量进行了验证。结果表明,双作物系数法计算的蒸散量与水量平衡法测定的蒸散量呈现出较好的相关性,全生育期蒸散量模拟值与实测值的均方根误差在10mm左右。双作物系数法计算的蒸腾量与稳定碳同位素法测得的耗水量亦呈现出较好相关性,模拟值与实测值的均方根误差在20mm左右。通过回归系数（b）、一致性指数（d）及均方根误差〖JP3〗（RMSE）的分析,认为双作物系数法可以估算并区分局部覆膜滴灌条件下干旱区夏玉米蒸散量,且2016年和2017年夏玉米全生育期内估算土壤蒸发量分别占蒸散量的21.33%和23.97%,作物蒸腾量分别占蒸散量的78.67%和76.03%。     

日光温室膜下滴灌番茄作物系数试验研究

作物系数是在没有实测需水量资料情况下,用参考作物蒸发蒸腾量来估算实际作物蒸发蒸腾量方法中重要的参数之一。根据实测气象数据计算出的参考作物蒸发蒸腾量和时域反射仪测得的番茄需水量,利用单作物系数法得到番茄作物系数Kc。通过对作物需水量和作物系数Kc的变化及影响因素进行分析,结果表明：温室膜下滴灌番茄作物需水量与温度、辐射呈正相关,而作物系数Kc与温度、辐射的线性关系不明显。对已求作物系数的可靠性进行验证,结果表明模型预测值和实测值的相对误差为8.2%,模型有效性指数达到89.3%,模型合理有效。研究成果对日光温室膜下滴灌作物需水量的计算及其灌溉制度的制定具有一定的参考价值。     

微润灌溉技术在大棚娃娃菜种植中的应用

微润灌水器是一种新型的微灌设备,为了更好的推广应用这一设备,本文将微润灌溉技术在大棚中进行应用。试验通过对比微润灌与滴灌两种灌水器、灌水器地表和地下两种应用形式对娃娃菜生长、耗水及产量等的影响,结果表明：在娃娃菜生长期内,各处理灌水量、株高和日耗水量均随着生育期的进行先增大后减小;不同处理之间,微润灌溉娃娃菜全生育期灌水量、株高、展开外叶片数、根面积、根长、日耗水量、全生育期总耗水量和产量高于滴灌灌溉,且同一种灌水器,除灌水量、日耗水量和全生育期总耗水量外,地下灌溉各指标均高于地表灌溉;水分利用效率从大到小依次为地下滴灌>地下微润灌>地表微润灌>地表滴灌。由此可见,微润灌溉尤其是地下微润灌溉适宜用于温室作物灌溉。     

西北干旱区滴灌棉田膜间土壤蒸发试验研究

膜间土壤蒸发是覆膜棉田水分消耗的主要组成部分,在干旱少雨的新疆石河子利用微型蒸渗仪观测了地下滴灌和膜下滴灌条件下,覆膜棉田膜间土壤水分蒸发,并对膜间不同位置处的土壤蒸发规律进行了试验研究,研究结果表明,滴灌条件下膜间土壤水分蒸发分别与气温、辐射、饱和水汽差以及相对湿度呈指数相关关系,与参考作物需水量呈线型相关关系,与表层土壤含水率呈指数关系;膜间土壤累积蒸发量在苗期最高、其次是花铃期、吐絮期最小;膜下滴灌条件下膜边土壤的蒸发量高于膜间（两条膜正中间的裸地）蒸发量;地下滴灌条件下,错位种植会导致灌溉水的无效蒸发,不利于灌溉水的高效利用。     

Crop coefficients for drip-irrigated processing tomato

Drip irrigation of processing tomato is increasing in the San Joaquin Valley of California (USA), a major tomato production area. Efficient management of these irrigation systems requires reasonable estimates of crop evapotranspiration (ET_c) between irrigations. A common approach for estimating ET_c is to multiply a reference crop evapotranspiration (ET_o) by a crop coefficient. However, a review of literature revealed mid-season crop coefficients for processing tomato to range from 1.05 to 1.25. Because of this variability, uncertainty exists in the crop coefficients appropriate for drip irrigation in the San Joaquin Valley. Thus, a study was initiated to determine the ET_c of processing tomato for drip irrigation in commercial fields and then calculate crop coefficients from the ET_c and ET_o data for the west side of the San Joaquin Valley. Crop ET_c was determined at five locations using the Bowen Ratio Energy Balance Method (BREB). Canopy coverage was also measured using a digital infrared camera. Average crop coefficients ranged from about 0.19 at 10% canopy coverage to 1.08 for canopy coverage exceeding about 90%. A second order regression equation reasonably described a relationship between crop coefficient and canopy coverage. Generic curves describing crop coefficient versus time of year were developed for various planting times.     

Crop evapotranspiration of processing tomato in the San Joaquin Valley of California, USA

Yield of processing tomato has increased by 53% over the past 35 years. Thus, concerns exist about the current seasonal crop evapotranspiration requirements of processing tomato compared to the past published requirements, which were about 645 mm. Also, the mid-season crop coefficient for processing tomato developed 35 years ago with sprinkler irrigation was 1.25, while a mid-season coefficient developed 20 years ago with subsurface drip irrigation was 1.05. Because of the age and variability of crop coefficients and the long-term yield increase, a study was conducted to determine the seasonal crop evapotranspiration and crop coefficients of processing tomatoes using the Bowen ratio energy balance method in eight commercial fields from 2001 to 2004. Measurements were made in both furrow- and drip-irrigated fields. Results showed seasonal crop evapotranspiration to range from 528 to 752 mm with an average of 648 mm. No statistical differences were found between furrow and drip irrigation. Mid-season crop coefficients varied between 0.96 and 1.09 with statistically similar values between furrow- and drip-irrigation for a given year. Current evapotranspiration rates were similar to those of the early 1970s, indicating that the water use efficiency of processing tomato increased substantially with time during the past 35 years.     

Peach orchard evapotranspiration in a sandy soil: Comparison between eddy covariance measurements and estimates by the FAO 56 approach

The evapotranspiration from a 3 to 4 years old drip irrigated peach orchard, located in central Portugal, was measured using the eddy covariance technique during two irrigation seasons, allowing the determination of crop coefficients. These crop coefficient values differed from those tabled in FAO Irrigation and Drainage Paper 56. In order to improve evapotranspiration estimates obtained from FAO tabled crop coefficients, a dual crop coefficient methodology was adopted, following the same guidelines. This approach includes a separation between the plant and soil components of the crop coefficient as well as an adjustment for the sparse nature of the vegetation. Soil evaporation was measured with microlysimeters and compared with soil evaporation estimates obtained by the FAO 56 approach. The FAO 56 method, using the dual crop coefficient methodology, was also found to overestimate crop evapotranspiration. During 2 consecutive years, measured and estimated crop coefficients were around 0.5 and 0.7, respectively. The estimated and measured soil evaporation components of the crop coefficient were similar. Therefore, the overestimation in evapotranspiration seems to result from an incorrect estimate of the plant transpiration component of the crop coefficient. A modified parameter to estimate plant transpiration for young, yet attaining full production, drip irrigated orchards is proposed based on field measurements. The method decreases the value of basal crop coefficient for fully developed vegetation. As a result, estimates of evapotranspiration were greatly improved. Therefore, the new approach seems adequate to estimate basal crop coefficients for orchards attaining maturity established on sandy soils and possibly for other sparse crops under drip irrigation conditions.     

通辽玉米滴灌灌溉制度

为更加合理制定玉米滴灌灌溉制度,以我国“节水增粮行动”为背景, 于2016年在内蒙古通辽开展玉米滴灌灌溉制度试验研究.根据试验区34 a的降雨资料进行降雨频率分析,选取不同水文年型的代表年,结合玉米滴灌试验得到实际耗水规律,对比6种灌溉处理在各生育阶段的变化情况,测定了株高、叶面积指数、玉米产量等指标.结果表明:中水处理作物性状及产量较高,且水分利用效率最高,为最佳灌水处理;以中水处理作为滴灌灌溉制度的参考依据,通过气象数据计算参考蒸发蒸腾量ET₀.利用实际耗水量获取各生育阶段作物系数,结合代表年型的ET₀计算需水量.根据降雨量,得到不同水文年型滴灌灌溉制度:枯水年覆膜滴灌灌溉定额1 575 m³/hm²,无膜滴灌灌溉定额1 785 m³/hm²;平水年覆膜滴灌灌溉定额1 125 m³/hm²,无膜滴灌灌溉定额1 425 m³/hm²;丰水年覆膜滴灌灌溉定额600 m³/hm²,无膜滴灌灌溉定额900 m³/hm².     

Economic feasibility of growing capsicum crop under drip irrigation in West Bengal, India

Drip irrigation system has been one of the technical means to improve water use efficiency. In India, this system is gaining popularity among fruit growers and in water scarced area but a substantial area is being covered annually under vegetables crops. One of the major concerns raised by farmers about this system is its economic viability. In present study, the economic viability of drip irrigation system for growing capsicum crop based on discounted cash flow technique (Net present worth and Benefit cost ratio) was explored. Eight irrigation treatments were laid under drip with and without plastic mulch. The irrigation levels were taken as 1, 0.8 and 0.6 of the crop evapotranspiration. The pan evaporation method was used for estimation of reference evapotranspiration and Water Balance Approach was used for irrigation scheduling. The average amount of water supplied under treatment VD (100% irrigation requirement supplied with drip) was found to be 415 mm for whole growing season of the crop. Similarly the amount of water was found to be 332 mm and 249 mm for the treatment 0.8VD (80% irrigation requirement supplied with drip) and 0.6VD (60% irrigation requirement supplied with drip) respectively. Highest yield was recorded in case of treatment VD + PM (100% irrigation requirement supplied with drip plus plastic mulch) followed by VD. Yield under treatments 0.8VD, 0.6VD, 0.8VD + PM and 0.6VD + PM were significant while treatments VD, VF and VF + PM were at par with the treatment VD + PM. Net Present Worth (NPW) was found to be positive for all the treatments. The highest NPW was obtained under treatment VD as Rs. 309,734.90 and lowest was in case of 0.6VD + PM as Rs. 144,172.24. The yield per mm of water used was reported to be at higher side as 35 in both the treatments VD and VD + PM. But the yield per mm of water used was found to be lowest as 18.07 and 19 in case of VF and VF + PM respectively.     

Effect of modern irrigation methods on growth and energy production of sweet sorghum (var. Keller) on a dry year in Central Greece

The subject of this project is to estimate the growth and productivity of sweet sorghum [Sorghum bicolor (L.)] var. Keller, under two different irrigation methods – the conventional surface drip method (two treatments) and the subsurface drip method – in a dry year in Central Greece, as an energy crop for the production of bio-ethanol. A field experiment was carried out on the experimental farm of the University of Thessaly during 2005, comprising of a completely randomized block design with four treatments in four blocks, including control (non-irrigated). In the treatments of surface drip method the evapotranspiration needs were satisfied by using full (100% ETm) and supplement (80% ETm) irrigation doses, while in the treatments of subsurface drip method only supplement irrigation water was used (80% ETm) with the aim of more efficient water conservation. Irrigation was fully automated, and application depths were determined, using a class A open evaporation pan for matching the evapotranspiration needs. The growth of the crop was measured by means of plant height and leaf area index, which were determined periodically throughout the growing period. Fresh and dry biomass productions were measured over six harvests covering the entire growth and production process of cultivation. The results of the first year demonstrated a clear superiority of the subsurface drip method on plant heights, leaf area index and total fresh and dry biomass production compared with the surface drip method for equal values of irrigation water. Maximum yield was attained by mid-September, before crop maturation, something which should be taken into consideration when choosing the best harvesting time of the crop. After late September, large negative growth rates were recorded, resulting in an appreciable drop in the final fresh and dry matter yield.     

淮北平原冬小麦作物系数的变化规律研究

【目的】研究淮北平原冬小麦作物系数的时空变化规律。【方法】采用水量平衡法、涡度相关法和Bouchet互补关系理论,结合Penman-Montieth方程,计算得到1991—2018年淮北平原冬小麦的作物系数;采用线性拟合法、Mann-Kendall趋势检验法和突变检验法滑动t检验法,结合ArcGIS,研究了作物系数在淮北平原的时空变化规律,并对影响因素进行分析。【结果】①淮北平原冬小麦全生育期的实际蒸散量的多年平均值为429.3 mm,参考作物蒸散量为541.3 mm,作物系数为0.79;②作物系数在不同生育阶段的变化为先减小后增大再减小;③作物系数在淮北平原全生育期由西北角向周围逐渐增大,高值中心呈现北移趋势;④作物系数与气候因子紧密相关,其中气温的影响最为显著,相对湿度和降水次之,风速最不显著。【结论】作物系数存在显著上升趋势,与气候因子关系紧密,需要关注作物需水量的变化。     

南方低山丘陵区滴灌葡萄蒸发蒸腾量实时预报

以浙江低山丘陵区永康灌溉试验站为背景,运用Penman-Monteith公式计算分析了永康长系列参考作物腾发量ET0及其变化规律,建立了ET0实时预报模型,并分析了参数A0取值方法对预报精度的影响。采用双作物系数法确定了滴灌葡萄逐日作物系数,建立了滴灌葡萄蒸发蒸腾量实时预报模型。运用实测的土壤含水率资料,根据水量平衡原理分析计算葡萄实际蒸发蒸腾量,与模型的预报值比较表明所建立的模型及其参数合理。     

基于ZigBee无线传感网络的自动滴灌系统设计

针对国内目前多数滴灌作业人工操作,费时费力效果不佳,部分自动滴灌系统实用性不强的情况,提出了基于ZigBee无线传感器网络的自动控制滴灌系统,介绍了系统的硬件构成,软件设计和工作过程。该系统能够监测植物土壤湿度、环境温度和光照的变化,通过无线网络将传感器信号反馈,结合传感器融合技术可对滴灌动作做出精确判断,实施高效的节水灌溉措施。