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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=658402
• 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.

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，与地表滴灌和高架喷灌系统相比，SDI 具有更高的用水效率，并且如果设计得当，可以减少根部区域以下的养分浸出。 对于加拿大东部的矿质和有机土壤，目前还没有关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的设计标准，以实现最大的作物产量。 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，那里集中种植蔬菜。两个地点均以甜椒 (Capsicum annuum. L) 和番茄 (S. lycopersicum) 作为试验作物，将滴灌线安装在土壤表面以下 20 和 30 厘米处，进行两次 SDI 处理。安装在土壤表面的滴水管将作为控制装置。两个SDI和DI处理将采用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），产生9个处理组合，并进行统计重复。将测量一些参数，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。每次灌溉施肥后，将从 9 个处理组合的吸渗仪收集孔隙水样品，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淋溶。**此外，作物小气候参数（冠层温度、气孔）将测量电导率、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)。 这些数据将催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为加拿大东部开发创新的作物用水生产力模型。对 2 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，将能够详细评估矿物土壤和有机土壤在两种 SDI 处理下的土壤湿度分布。计算机建模将能够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）。 * *该研究为加拿大和科学与工程界带来了有关 SDI、有机土壤灌溉、CWSI 和作物水分生产力模型的新发现。由于竞争性用水需求和气候变化以及不断上涨的水成本而面临水资源短缺的作物生产者、灌溉者和水管理者将从研究结果中受益。研究成果的采用将进一步提高每年价值15亿加元的加拿大水果和蔬菜产业的可持续性和竞争力。该项目将培训麦吉尔大学的五名研究生和几名本科生，从而为灌溉和农业部门培养高技能人才做出贡献。