Optimizing water management for sustainable use of agricultural lands and water

优化水管理以可持续利用农田和水

• 批准号: RGPIN-2016-06041
• 负责人: SriRanjan, Ramanathan
• 金额: $ 1.75万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709879
• 关键词: Optimizing; water; management; sustainable; use

Irrigation is expanding in Southern Manitoba in areas where salinization from poor quality groundwater has been a major problem. Wherever irrigation water is applied to plants, the plants take up the water and leave behind the salts within the root zone leading to salinization. Drainage systems can be used to remove the excess water applied to wash the salts below the rootzone to mitigate salinization. However, conventional drainage systems may also over-drain the field, removing valuable nutrients and water. Controlled drainage can be used to overcome this shortcoming. Previous NSERC funded field-scale research showed that properly designed and managed irrigation and drainage systems can significantly improve yield by 30% in potatoes and 15% in corn. However, major nutrient outflows were observed in tile drainage during spring snowmelt period as well as during high intensity rainfall. Controlled drainage using Drainage Control Structures (DCS) that can hold back the water within the field was shown to lower the nutrient outflow by 90% compared to conventional drainage. The use of DCS was found to be a best management practice to minimize nutrient export from the field. However, this practice may negatively impact soil trafficability due to the high water table in the spring. The proposed research will optimize the operation of controlled drainage to hold back the water and nutrients within the field while allowing improved trafficability. The DCS can also facilitate subirrigation where the irrigation water is applied through the DCS into the subsurface drains. However, the upward flux of subirrigated water may be restricted if the soil beneath the root zone becomes too dry. The data from this research will be used in Hydrus 2D/3D model to simulate different soil types and weather conditions and identify soils suitable for subirrigation. In the short term, the main objectives will be to (1) monitor the water and nutrient movement within the root zone to assess the impact of subirrigation/drainage systems on crop yield and water quality; (2) determine the optimum depth of the water table that will still allow field operations while conserving the water and nutrients within the field; (3) determined the optimum depth of water table that will allow subirrigation during periods of high evapotranspiration. I will use the NSERC Discovery grant to partially support three PhD, five MSc, and twelve BSc students. Farmers will benefit from improved yields and better nutrient retention within the field. In the long term, the objective will be to optimize the integrated water management systems combining subirrigation/controlled drainage systems and develop a protocol for site selection for successful implementation. The long-term goal is to manage the water and nutrients within the field and attain agricultural sustainability at the farm-scale and minimize the nutrient outflow into the rivers and lakes.

马尼托巴省南部地区的灌溉正在扩大，这些地区因地下水质量差而盐碱化一直是一个主要问题。无论在何处向植物施用灌溉水，植物都会吸收水分并在根部区域留下盐分，从而导致盐化。排水系统可用于去除用于冲洗根区以下盐分的多余水，以减轻盐渍化。然而，传统的排水系统也可能会使田地过度排水，从而带走宝贵的养分和水分。 可以采用控制排水来克服这个缺点。 此前 NSERC 资助的田间规模研究表明，设计和管理得当的灌溉和排水系统可以显着提高马铃薯产量 30% 和玉米产量 15%。 然而，在春季融雪期间以及高强度降雨期间，在瓷砖排水中观察到主要的养分外流。 与传统排水相比，使用排水控制结构 (DCS) 进行控制排水可以将水阻挡在田间，可将养分流出减少 90%。研究发现，使用 DCS 是最大程度地减少田间养分输出的最佳管理实践。 然而，由于春季地下水位较高，这种做法可能会对土壤的交通能力产生负面影响。 拟议的研究将优化控制排水的运行，以保留田地内的水分和养分，同时提高通行性。 DCS 还可以促进地下灌溉，其中灌溉水通过 DCS 进入地下排水沟。 然而，如果根区下方的土壤变得过于干燥，地下灌溉水的向上流量可能会受到限制。 这项研究的数据将用于 Hydrus 2D/3D 模型来模拟不同的土壤类型和天气条件，并识别适合地下灌溉的土壤。 短期内，主要目标是（1）监测根区内的水和养分运动，以评估地下灌溉/排水系统对作物产量和水质的影响； (2) 确定在保留田间水和养分的同时仍允许田间作业的最佳地下水位深度； (3) 确定在高蒸散期允许进行地下灌溉的最佳地下水位深度。 我将使用 NSERC 发现补助金来部分支持三名博士生、五名硕士生和十二名理学士学生。农民将受益于田间产量的提高和养分的更好保留。 从长远来看，目标是优化结合地下灌溉/控制排水系统的综合水管理系统，并制定成功实施的选址协议。长期目标是管理田间的水和养分，实现农场规模的农业可持续发展，并最大限度地减少流入河流和湖泊的养分流失。