Approach of water-salt regulation using micro-sprinkler irrigation in two coastal saline soils

This study aimed to investigate whether saline silt and sandy loam coastal soils could be reclaimed by micro-sprinkler irrigation.The experiments were run using moderately salt-tolerant tall fescue grass.Micro-sprinkler irrigation in three stages was used to regulate soil matric potential at a 20-cm soil depth.Continued regulation of soil water and salt through micro-sprinkler irrigation consistently resulted in an increasingly large low-salinity region.The application of the three stages of soil wateresalt regulation resulted in an absence of salt accumulation throughout the soil profile and the conversion of highly saline soils into moderately saline soils.There were increases in the plant height,leaf width,leaf length,and tiller numbers of tall fescue throughout the leaching process.The results showed that micro-sprinkler irrigation in three soil water and salt regulation stages can be used to successfully cultivate tall festuca in highly saline coastal soil.This approach achieved better effects in sandy loam soil than in silt soil.Tall fescue showed greater survival rates in sandy loam soil due to the rapid reclamation process,whereas plant growth was higher in silt soil because of effective water conservation.In sandy loam,soil moisture should be maintained during soil reclamation,and in silt soil,soil root-zone environments optimal for the emergence of plants should be quickly established.Micro-sprinkler irrigation can be successfully applied to the cultivation of tall fescue in coastal heavy saline soils under a three-stage soil wateresalt regulation regime.

Effects of water application intensity of micro-sprinkler irrigation and soil salinity on environment of coastal saline soils

To achieve the greatest leaching efficiency,water movement must occur under unsaturated flow conditions.Accordingly,the water application intensity of irrigation must be chosen carefully.The aim of this study was to evaluate the impact of the water application intensity of micro-sprinkler irrigation on coastal saline soil with different salt contents.To achieve this objective,a laboratory experiment was conducted with three soil salinity treatments(2.26,10.13,and 22.29 dS/m)and three water application intensity treatments(3.05,5.19,and 7.23 mm/h).The results showed that the effect of soil salinity on soil water content,electrical conductivity,and pH was significant,and the effect of the water application intensity was insignificant.High soil water content was present in the 40e60 cm profile in all soil salinity treatments,and the content was higher in the medium and high water application intensity treatments than in the low-intensity treatment.Significant salt leaching occurred in all treatments,and the effect was stronger in the high soil salinity treatment and medium water application intensity treatment.In the medium and high soil salinity treatments,pH exhibited a decreasing trend,with no trend change in the low soil salinity treatment,and the pH value was higher in the medium water application intensity treatment than in the other two treatments.These results indicated that the three intensities evaluated had no statistically different effect on the electrical conductivity of saturated soil-paste extracts(EC)in the upper 20 cm of the soil profile,and it would be better to maintain a lower value of the water application intensity.

A Spatial Analysis of Irrigation Technology

The nature of spatial spillovers in the adoption of irrigation technology is examined in this paper. Adopting a new technology is a decision that is based on economic and individual-specific factors. One of these individual factors might be communication with other users. It makes sense to expect that contact between users and non-users would follow a spatial pattern, and if knowledge spillovers are important to the adoption decision then resource managers need to be aware of their existence. Using counties in the Texas High Plains as the study area, the adoption of center pivot technology is examined using both Ordinary Least Squares and spatial regression models to determine if knowledge spillovers exist. Ultimately, no evidence was found that adoption practices in a county affects its neighbors;however, geographic location does matter to who adopts and when.

Dynamic Variation of Land-use Types of the Constructed Wetland before and after Oil-field Water Irrigation Based on 3S Technology

[Objective] The study aimed at analyzing the dynamic variation of land-use types of the constructed wetland before and after oil-field water irrigation based on 3S technology. [Method] At semi-arid and arid areas in the west of Jilin Province, water resource balance between the amount of oil-field water supply and ecological water requirement in the constructed wetland irrigated by oil-field water during 2001-2010 was investigated firstly. Afterwards, based on 3S technology, the partition and dynamic variation of land-use types of the constructed wetland before and after oil-field water irrigation in 2001, 2006, 2008 and 2010 were analyzed. [Result] The annual ecological water requirement of the constructed wetland from 2003 to 2010 varied from 1.62×106 to 2.24×106 m3, and the annual amount of oil-field water supply in the region changed from 2.12×106 to 2.84×106 m3, which showed that the supply amount of oil-field water could meet the basic ecological water requirement of the constructed wetland. Meanwhile, compared with 2001, the areas of water region and paddy field in 2010 increased by 2.3 and 10.0 times, and the areas of forest and marsh rose by 40.15% and 29.5.0% respectively. [Conclusion] Water shortage and ecological environment problem of arid and semi-arid areas had been improved by oil-field water irrigation.

Improving Strawberry Irrigation with Micro-Sprinklers and Their Impact on Pest Management

Overhead aluminum sprinklers, which are used during the early stages of strawberry crop development to establish transplants and to leach out salts from the root zone, deliver significant volumes of water. Micro-sprinklers, which are typically used in orchard crops, were evaluated in a commercial strawberry field in California as an alternative to conventional aluminum sprinklers to conserve water without any negative impact on yields. In addition to the water consumption, data were collected from multiple plots within each treatment to determine the impact on plant growth, disease incidence, and seasonal yield. Micro-sprinklers used 32% less water than aluminum sprinklers during a three-week period without affecting fruit yield. They also appeared to lessen the severity of powdery mildew and botrytis fruit rot. This is the first study reporting the use of micro-sprinkler system, which can be a good alternative to the aluminum sprinklers to conserve irrigation water.

Improving winter wheat grain yield and water-/nitrogen-use efficiency by optimizing the micro-sprinkling irrigation amount and nitrogen application rate

Available irrigation resources are becoming increasingly scarce in the North China Plain (NCP),and nitrogen-use efficiency of crop production is also relatively low.Thus,it is imperative to improve the water-use efficiency (WUE) and nitrogen fertilizer productivity on the NCP.Here,we conducted a two-year field experiment to explore the effects of different irrigation amounts (S60,60 mm;S90,90 mm;S120,120 mm;S150,150 mm) and nitrogen application rates (150,195 and 240 kg ha^(–1);denoted as N1,N2 and N3,respectively) under micro-sprinkling with water and nitrogen combined on the grain yield(GY),yield components,leaf area index (LAI),flag leaf chlorophyll content,dry matter accumulation (DM),WUE,and nitrogen partial factor productivity (NPFP).The results indicated that the GY and NPFP increased significantly with increasing irrigation amount,but there was no significant difference between S120 and S150;WUE significantly increased first but then decreased with increasing irrigation and S120 achieved the highest WUE.The increase in nitrogen was beneficial to improving the GY and WUE in S60 and S90,while the excessive nitrogen application (N3) significantly reduced the GY and WUE in S120 and S150 compared with those in the N2 treatment.The NPFP significantly decreased with increasing nitrogen rate under the same irrigation treatments.The synchronous increase in spike number (SN) and 1 000-grain weight (TWG)was the main reason for the large increase in GY by micro-sprinkling with increasing irrigation,and the differences in SN and TGW between S120 and S150 were small.Under S60 and S90,the TGW increased with increasing nitrogen application,which enhanced the GY,while N2 achieved the highest TWG in S120 and S150.At the filling stage,the LAI increased with increasing irrigation,and greater amounts of irrigation significantly increased the chlorophyll content in the flag leaf,which was instrumental in increasing DM after anthesis and increasing the TGW.Micro-sprinkling with increased amounts of irrigation or excessive nitrogen application decreased the WUE mainly due to the increase in total water consumption (ET)and the small increase or decrease in GY.Moreover,the increase in irrigation increased the total nitrogen accumulation or contents (TNC) of plants at maturity and reduced the residual nitrate-nitrogen in the soil (SNC),which was conducive to the increase in NPFP,but there was no significant difference in TNC between S120 and S150.Under the same irrigation treatments,an increase in nitrogen application significantly increased the residual SNC and decreased the NPFP.Overall,micro-sprinkling with 120 mm of irrigation and a total nitrogen application of 195 kg ha^(–1) can lead to increases in GY,WUE and NPFP on the NCP.

The water-saving potential of using micro-sprinkling irrigation for winter wheat production on the North China Plain

The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving potential of using micro-sprinkling irrigation(MSI)for winter wheat production,field experiments were conducted from 2012 to 2015.Compared to traditional flooding irrigation(TFI),micro-sprinkling thrice with 90 mm water(MSI1)and micro-sprinkling four times with 120 mm water(MSI2)increased the water use efficiency by 22.5 and 16.2%,respectively,while reducing evapotranspiration by 17.6 and 10.8%.Regardless of the rainfall pattern,MSI(i.e.,MSI1 or MSI2)either stabilized or significantly increased the grain yield,while reducing irrigation water volumes by 20–40%,compared to TFI.Applying the same volumes of irrigation water,MSI(i.e.,MSI3,micro-sprinkling five times with 150 mm water)increased the grain yield and water use efficiency of winter wheat by 4.6 and 11.7%,respectively,compared to TFI.Because MSI could supply irrigation water more frequently in smaller amounts each time,it reduced soil layer compaction,and may have also resulted in a soil water deficit that promoted the spread of roots into the deep soil layer,which is beneficial to photosynthetic production in the critical period.In conclusion,MSI1 or MSI2 either stabilized or significantly increased grain yield while reducing irrigation water volumes by 20–40%compared to TFI,and should provide water-saving technological support in winter wheat production for smallholders on the North China Plain.

Adoption of small-scale irrigation technologies and its impact on land productivity:Evidence from Rwanda

In an attempt to identify solutions to the effects of erratic rainfall patterns and droughts that limit agricultural production growth,the Rwandan government has recently increased investments in irrigation development.In this study,we analyze the adoption of small-scale irrigation technologies(SSITs)and its impact on land productivity using cross-sectional data from a sample of 360 farmers in Rwanda.The study uses the propensity score matching technique to address potential self-selection bias.Our results reveal that adoption decisions are significantly influenced by factors such as education,farm size,group membership,gender,extension services,access to credit,access to weather forecast information,risk perceptions,access to a reliable source of water for irrigation,awareness of rainwater harvesting techniques,and awareness of subsidy programs.In addition,the results show that the adoption of SSITs has a significantly positive impact on land productivity.The study concludes with policy implications that highlight the need to promote the adoption of SSITs among farmers as a strategy to improve agricultural productivity and food security in Rwanda.

The Optimization of Irrigation Networks Using Genetic Algorithms

Mathematical-computational optimisation models of irrigation networks with a distributed flow that are capable of providing hydraulic data are important for understanding the behaviour of a system in relation to the distribution of the hydraulic head (energy) and the pressure in the pipes of the network. The objective of this study was to examine the distribution of the parameters of hydraulic irrigation pipes, which were optimised using genetic algorithms. The degree of the optimisation was evaluated with the help of the genetic algorithms based on the diameters of stretch of the network: two for the lateral lines, four for the derivation lines, four for the secondary lines and one for the main line. A MatLab code was developed that considered all of the losses of energy, both distributed losses and those at specific locations between the beginning of the network and the pump system. The sensitivity analysis was based on the variations in the slope of the ground (0%, 2.5% and 5%). The results show that for pipes with a distributed flow, the influence of the behaviour of the kinetic energy in the pipe contributed to the distance between the energy lines and the piezometric lines at the beginning of each stretch after the decrease in the diameter of the pipes. At the end of the pipes, the values of the energy lines and the piezometric lines were very similar, and they were essentially the same for the final emitter.

基于物联网农业灌溉系统精准控制模型的研究

为进一步提升我国农业灌溉系统的综合作业效率,体现灌溉的先进性与科学性,提出以精准控制模型为切入点,以物联网技术为主体支撑平台,针对其作业系统展开设计与优化。通过引入物联网强大的系统性架构,规范与强化各网络节点的部署与协作关系,科学搭建用于实现精准灌溉控制的数学模型,同时导入合理的系统软件设计程序与硬件功能组件配置,形成完整集成式的农业智能灌溉系统。结果表明:基于物联网平台技术的精准控制模型应用后,整体的作业效率得到显著提升,系统精准度、系统响应率分别相对提高了6.25%和7.68%,动作延迟率相对降低了2.72%,灌溉节水效率提升至91.50%。物联网平台下的精准控制模型应用效果良好,设计理念正确,可为灌溉领域实施节能降耗提供参考。

基于蓝牙Mesh技术的校园绿化浇灌系统设计

调研发现,很多高校对校园绿化管理手段有限,虽投入大量人力、物力,但经济效益差,水资源浪费现象比较突出。基于此,设计了一种以传感器+单片机为终端控制单元、利用蓝牙Mesh组网通信的校园绿化浇灌系统。系统具有组网便捷、覆盖面广、控制灵活、网络健壮性强等优点。实验结果表明:系统在不同的环境因素下,能自主判断植物需求,按照既定策略实施浇灌,系统运行正确率平均达91%。将该系统在高校推广使用,能有效降低后勤运营成本,节约水资源,提高校园绿化养护效率。

西南水稻主产区用水现状与绿色高效灌排技术

西南水稻主产区面临季节性干旱、工程性缺水等生产问题,绿色高效灌排技术是该区域实现节水稳产增效的关键举措,对保障国家粮食安全具有重要意义。本文系统梳理了包括云南省、贵州省、四川省、重庆市在内的西南地区水稻生产用水现状和灌排技术现状,阐述了西南水稻主产区绿色高效灌排体系的基本特征、绿色高效灌排的具体技术类型,提出了由稻田精准需水预报、灌区精量配水管理、田间高效用水管理、田间高效排水管理构成的绿色高效灌排技术模式。研究发现,西南水稻主产区水资源丰富但时空分布不均,节水灌溉和排水技术落后且对各地区气候条件、水资源量、地形的适用性有较大差异。建议研发稻田灌排高效协同调控新技术、推广绿色高效灌排技术体系、优化稻田水肥运筹模式、开发稻田智能灌排与信息化管理系统、构建水稻绿色高效灌排技术多维推广体系,据此推动西南水稻主产区节水提质增效与绿色减污降排多赢。

新型灌溉技术在果树中应用的研究进展

果树是我国农业中重要的支柱产业,而我国水资源匮乏是影响果树生产的瓶颈问题。近年,研究学者根据果树的需水特性、生长发育规律、栽培环境条件等因素,研制多种新型节水灌溉技术,并得到较好的试验印证效果,该文将国内外有关新型灌溉技术在果树中的研究进行综合阐述,并对今后新型灌溉技术进行展望,以期将新型灌溉技术更好地服务于果树生产、提高果园管理水平提供借鉴。

京郊山区果园高效灌溉技术研究与应用

北京地区有大量的山区果园,分布在京郊西南部、北部与东北部,与平原区果园相比,山区果园的地形一般较为复杂,地形存在落差,存在大量的坡地且坡度较大,果园灌溉的供水条件较差等特征。文章结合切身的技术服务工作,以房山区佛子庄乡东班各庄村北山坡苹果园为对象,通过采集果园地理信息数据,现场踏勘,工程测绘,结合果树生长状况及实际管理措施等,从果园高效节水灌溉技术适宜性选配出发,应对山坡地形变化引起压力不均匀变异进行压力补偿,面向复杂地形地质条件,开展水肥药一体化灌溉系统集成,是山坡高效灌溉技术推广的关键。

基于GPRS无线通讯技术的自动化灌溉系统设计

针对传统的大水漫灌等灌溉方式灌水不均、容易造成农作物病害或涝死、浪费水资源和人工成本较高的问题,基于GPRS无线通讯技术对自动化灌溉系统进行了设计。为了获取有效的灌溉数据,同时能够对数据进行统计、分析和预测,设计了自动灌溉数据信息的预处理方法,并采用多元线性回归预测模型对灌溉数据进行预测。为了验证该自动化灌溉系统的性能,对其进行了数据采集试验和灌溉预测试验,结果表明:系统对灌溉数据监测和预测的准确率均较高。

高含沙水滴灌灌水器堵塞机制及防堵技术研究进展

为解决黄河水中粒径小于0.10 mm细小泥沙颗粒引发的滴灌灌水器堵塞问题。通过文献调研,回顾了高含沙水滴灌条件下灌水器物理堵塞机制相关研究进展,并提出了进一步研究方向。细小泥沙颗粒含量较高的浑水滴灌时,滴头堵塞主要是含沙量、泥沙粒径与颗粒级配耦合作用的结果。滴灌系统工作条件如工作压力的动态变化有助于移除流道内黏、粉等细颗粒堵塞物质,促进较大泥沙颗粒排出流道;灌溉水温越高,滴头抗物理堵塞性能越强;对浑水加气和磁化处理可改变毛管内水流水力特性及悬浮泥沙运动规律,增强水流拖拽力,减小管道内泥沙淤积量。此外,施肥增强了水体中泥沙颗粒间的絮凝作用,对浑水水肥一体化滴灌滴头堵塞具有明显加速作用。浑水含沙量、粒径和颗粒级配是引发滴头物理堵塞的重要因素,确定易引发滴头堵塞的敏感含沙量、颗粒粒径段,选用适宜肥料种类和施肥浓度阈值,优化滴灌系统工作条件参数是改变毛管内泥沙颗粒运移和沉积规律、延缓滴头堵塞进程、提高水肥一体化滴灌水肥利用效率的有力措施;采用统一的灌水试验方法,充分利用现代测试手段,结合生产实际有针对性地改进工程技术处理措施是解决滴头堵塞问题的必要途径。

无线灌溉控制系统的设计与试验

南疆的温带大陆性气候为棉花生长提供了良好的自然条件,该地区棉花种植范围广,但干旱少雨。为解决传统灌溉方式自动化程度低、水资源浪费严重等问题,本文以LoRa无线通信、传感器、远程控制等技术,设计了一套基于LoRa通信技术的农业灌溉控制系统。该系统采用高精度土壤墒情传感器,远程在线采集土壤温湿度,远程控制电磁阀开关等控制方式,获得作物最佳灌溉时间、灌溉水量。试验结果表明:应用该系统进行灌溉后,灌溉效率有了显著提高,灌溉均匀度可达95%以上,效果良好,可为大田灌溉提供参考。