Ontario Grain Farmer March 2021

ONTARIO GRAIN FARMER 25 MARCH 2021 Grain crops in Ontario can be irrigated by drip irrigation (on the surface or buried) or by overhead irrigation (travelling guns or centre pivot). Water sources Conditions Ground water fed ponds far from sensitive features (such as wetlands, streams, other water takers etc.) Less than 4m deep and more than 100m from sensitive features Less than 7m deep and more than 250m from sensitive features Great Lakes or connecting rivers/channels Less than 1 Million L/day Small ponds fed by runoff Less than 15 acre-inches or 1500 m3 (e.g. 30m x 30m x 5m with 3:1 sloped sides) TABLE 2: HYDROLOGIC ASSESSMENTS ARE NOT REQUIRED FOR THE FOLLOWING PTTW APPLICATIONS. buried at 14 to 18 inches below surface. Drip line spacings range from 60, 44, and 30-inch spacings with slight yield benefits from narrower spacings. Buried systems must have both a header and footer manifold pipe to maintain water flow throughout the network and for periodic flushing. on the farm property that have been built by the landowner such as ponds collecting surface or tile drainage. Most PTTW applications will require that you complete a water taking impact assessment (hydrologic or hydrogeological study) by a qualified professional. The cost of this assessment is the irrigator’s responsibility and typically ranges from $10,000 to $50,000. Table2outlines the situationswhere a hydrologic assessment is not generally required. PTTW holders must keep records of the daily pumping volumes and report these back to the MECP at the end of each calendar year. PTTW must be renewed before they expire — typically every five or 10 years. Each PTTW is unique and may have other monitoring and reporting requirements. In addition to flow rate limits and daily volume limits, some PTTW have additional limits or cut-offs at certain stream flows or other water level conditions. For more information, visit Permits to Take Water at www.ontario.ca/page/permits-take- water. There are no fees required by MECP for PTTWs for agricultural irrigation. EQUIPMENT Grain crops in Ontario can be irrigated by drip irrigation (on the surface or buried) or by overhead irrigation (travelling guns or centre pivot). Drip irrigation is based on the concept of preventing rather than relieving moisture stress. The crop response to this approach is positive. Drip systems are the most water efficient option and are known to generate the most crop per drop of water. A drip irrigation system supplies a small amount of water to the root zone of the plants. The system components can be downsized because water is delivered more continuously (usually daily, when needed) and only the rooting areas are watered. As compared to an overhead irrigation system, the pumps required for drip irrigation are smaller, less power is required, less energy is used, and the water conveyance lines are smaller. The buried drip irrigation systems that have been successful in Ontario have drip lines Subsurface Drip Irrigation (SDI) Traveling gun Centre pivot Easily automated and low labour 3 3 Can be applied on windy days or during spraying operations 3 Does not wet the foliage, which reduces disease problems 3 Does not remove crop protection materials 3 Is well suited for fertigation (uniform water distribution) 3 possible Low pressure/energy requirements 3 3 Low flow rates 3 System can operate in uneven field shapes 3 3 System is portable, can be moved between farms 3 Well suited for electric power source 3 3 Purchasing cost is lower than drip irrigation 3 3 Per acre costs for 100-acre field (from Irrigation BMP book 2004) Power supply not included $2,325 $700 $750 TABLE 3: COMPARISON OF ADVANTAGES AND DISADVANTAGES OF GRAIN CROP IRRIGATION EQUIPMENT. continued on page 26