Soil-Plant-Water Dynamics and Water Productivity Benefits of Subsurface Drip Irrigation

地下滴灌的土壤-植物-水动力学和水生产力效益

• 批准号: RGPIN-2014-04286
• 负责人: Madramootoo, Chandra
• 金额: $ 1.75万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610941
• 关键词: Soil; Plant; Water; Dynamics; Productivity

An innovative five year research program is to be undertaken, aimed at investigating the potential efficacy and benefits of subsurface drip irrigation (SDI) for intensive vegetable production in Eastern Canada. Our hypothesis is that SDI has a superior water use efficiency compared to surface drip and overhead sprinkler irrigation systems, and if properly designed could reduce nutrient leaching below the root zone. There are currently no design criteria on the optimum depth of placement of the drip lines below the soil surface, and the optimum amount of water to be applied, to achieve maximum crop yields, for both mineral and organic soils in Eastern Canada. The research combines field, greenhouse and computer modeling studies. Field studies will be conducted on a mineral soil at the McGill University Horticulture Research Station, and on an organic soil, 100 km south of Montreal, where vegetables are intensively cultivated. Using sweet bell pepper (Capsicum annuum. L) and tomato (S. lycopersicum) as test crops at both sites, drip irrigation lines will be installed at 20 and 30 cm below the soil surface, resulting in two SDI treatments. Drip lines installed on the soil surface will serve as a control. Three soil water replenishment levels (100%, 70% and 50% of field capacity – representing 3 levels of crop water stress) will be applied to the two SDI and the DI treatments, resulting in 9 treatment combinations, which will be statistically replicated. Several parameters including crop yield and marketable harvest, rainfall, evapotranspiration, irrigation applications, and soil moisture will be measured. Pore water samples will be collected from suction lysimeters in the 9 treatment combinations after each fertigation, and analyzed for nitrite, nitrate, and ammonia. This data will inform decisions about the appropriate depth of placement of the SDI lines below the soil surface, for optimum water savings and crop yields, and reduced nutrient leaching on mineral and organic soils. Additionally crop-microclimate parameters (canopy temperature, stomatal conductance, leaf chlorophyll content, and photosynthetically active radiation) will be measured, and used to develop a Crop Water Stress Index (CWSI) for each water stressed condition for both SDI and DI. This data will result in a new technique for irrigation scheduling based on crop indicators, rather than on traditional soil moisture measurements. Furthermore, the CWSI, water savings and crop yield data will enable the development of an innovative crop-water productivity model for Eastern Canada. A greenhouse study with the 2 test crops, coupled with a computer simulation study using HYDRUS-2D, will permit a detailed assessment of soil moisture distribution under the two SDI treatments for both mineral and organic soils. The computer modeling will enable the derivation of SDI design criteria (depth of installation and emitter spacing) for a range of soils and environmental conditions. The research brings new findings on SDI, irrigation of organic soils, CWSI and crop-water productivity modeling to Canada and the scientific and engineering communities. Crop producers, irrigators and water managers who are faced with water scarcity due to competing water demands and climate variability, and rising water costs will benefit from the research findings. The sustainability and competitiveness of the Canadian fruit and vegetable industry, worth $1.5 billion annually, will be further enhanced by adoption of the research results. Five graduate students and several undergraduate students at McGill University will be trained under the project, thereby contributing to the development of highly skilled personnel for the irrigation and agricultural sectors.

我们将开展一项为期五年的创新研究计划，旨在调查地下滴灌 (SDI) 对加拿大东部集约化蔬菜生产的潜在功效和效益。我们的假设是，与地表滴灌和地表滴灌相比，地下滴灌具有更高的用水效率。喷灌头顶灌溉系统，如果设计得当，可以减少根部区域以下的养分浸出。目前，对于滴灌线在土壤表面以下的最佳放置深度以及最佳施水量还没有设计标准。实现矿物和作物产量最大化该研究结合了实地、温室和计算机建模研究。 实地研究将在麦吉尔大学园艺研究站的矿质土壤和蒙特利尔以南 100 公里处的有机土壤上进行，那里使用甜椒 (Capsicum annuum. L) 和番茄 (S.番茄）作为两个地点的试验作物，滴灌线将安装在土壤表面以下 20 和 30 厘米处，从而在土壤表面安装两条 SDI 处理线。三个土壤水分补给水平（田间持水量的 100%、70% 和 50%——代表作物水分胁迫的 3 个水平）将应用于两个 SDI 和 DI 处理，产生 9 种处理组合，并将对其进行审查。包括作物产量和适销收成、降雨量、蒸散量、灌溉应用和土壤湿度在内的几个参数将在 9 个处理组合后通过抽吸式蒸渗仪进行测量。每次灌溉施肥，并分析亚硝酸盐、硝酸盐和氨，这些数据将为有关 SDI 线在土壤表面以下的适当放置深度的决策提供信息，以实现最佳节水和作物产量，并减少矿物质和有机土壤上的养分浸出。 。 将测量其他作物小气候参数（冠层温度、气孔导度、叶片叶绿素含量和光合有效辐射），并用于针对 SDI 和 DI 的每种水分胁迫条件制定作物水分胁迫指数 (CWSI)。将产生一种基于作物指标而不是传统土壤湿度测量的灌溉调度新技术。此外，CWSI、节水和作物产量数据将有助于开发创新的作物水生产率模型。对加拿大东部的两种测试作物进行的温室研究，加上使用 HYDRUS-2D 的计算机模拟研究，将能够对两种 SDI 处理下的矿物质和有机土壤的土壤湿度分布进行详细评估。针对一系列土壤和环境条件推导 SDI 设计标准（安装深度和发射器间距）。 该研究为加拿大以及由于竞争性用水需求和气候变化而面临水资源短缺的作物生产者、灌溉者和水管理者带来了关于 SDI、有机土壤灌溉、CWSI 和作物水生产力模型的新发现。麦吉尔大学的五名研究生和几名本科生将进一步提高每年价值 15 亿美元的加拿大水果和蔬菜产业的可持续性和竞争力。将接受培训在该项目下，从而促进灌溉和农业部门高技能人才的培养。