Water Wisdom: Best Practices for Efficient Water Management in Agriculture
By Tim Huggins, Program Manager
Water is a critical resource, and managing it efficiently is essential to ensure sustainability and productivity in agriculture. With increasing pressures on water resources from droughts, changing weather patterns that often bring heavier but less frequent rainfall, adopting best practices for water management is more important than ever. Gain more confidence in managing this vital resource as we review the key principles of efficient irrigation practices, as well as the role conservation measures and soil health play in water management.
The 4R's of Irrigation Management
The 4R nutrient management strategy has been used for decades and is widely known. However, as outlined by Utah State University, applying this framework to irrigation management is also a great method for efficient water use in agriculture.
1. Right Source: The main sources of irrigation water are groundwater and surface water (either from natural water bodies or constructed tail-water reservoirs). Choosing the right source for irrigation is crucial but challenging. Here are a few items to research in your area:
Know your legal extent, reliability, and duration of your water rights. Consult with your state agency in charge of overseeing agriculture withdrawals to ensure proper procedures are followed.
Consider the salinity and quality of your water source, and how these factors might change during droughts or external influences.
If feasible, research purchasing or leasing water shares to mitigate drought impacts. Ensure all aspects, including costs and limitations, are thoroughly evaluated to avoid purchasing invalid or inadequate water rights.
2. Right Rate: Modifying irrigation rates is a simple and cost-effective way to improve water management. Key steps include:
Water Measurement and Monitoring: Accurate water measurement is crucial. Inaccurate measurements can undermine all efforts to refine irrigation management.
Adjusting Irrigation Rates: Modify flow rates, set lengths, nozzle sizes, and other methods to ensure the irrigation rate matches soil intake rates, prevents soil water depletion, and meets ET demand, reducing runoff and water losses.
Determining the Right Rate: Use various methods to determine the appropriate irrigation rate:
Soil Moisture Monitoring: Use the feel method or soil moisture sensors.
Irrigation Scheduler Systems: Utilize weather data to estimate ET, calculate water balances, and recommend irrigation rates.
Commercial Programs: Employ crop growth models, soil characteristics, and ET estimated from satellite or aerial imagery, with options for autonomous irrigation.
Variable-Rate Irrigation Technology: Consider using variable-rate irrigation technology for pivots and linears, which allows for speed control and full zone control options. Develop correct and evolving prescriptions based on soil data, yield maps, weather data, and farmer experience. Ensure investments in this technology are feasible and economical.
3. Right Time: While this is closely linked to the right rate component, refine irrigation schedules as best as possible to maximize water uptake by crops and minimize evaporation losses.
Use water when it most benefits crops, such as during corn tasseling, or R3-R6 for soybeans.
Monitor weather events, while considering the system’s capacity to catch up later.
Soil moisture sensors, ET models, and variable irrigation programs can be used to further refine schedules.
Understand your moisture sensors, whether they are capacitance (% water volume), or tensiometers (centibars), and how the numbers differ for triggering an irrigation.
4. Right Place: Ensure water is distributed uniformly across the field and close to the soil surface to prevent dry spots and waterlogging. This minimizes evaporation, wind drift, and runoff and helps maximize the water stored in the root zone. Keep pressurized systems properly maintained to ensure even water applications. Allocate limited water supplies to the most productive and/or water-efficient areas first. Finally, check with your University Extension Service for irrigation calculators and planners to assist with complex decisions.
The Role of Soil Health and Conservation Practices in Water Management
Water management doesn’t end there though. Many other aspects of your operation can not only save water but also protect water quality by reducing runoff and preventing pollutants from entering water bodies. Healthy soils with good structure and organic matter content have better water-holding capacity and infiltration rates are crucial for sustaining crops during dry periods.
Effective conservation practices that improve soil health and water management include:
Reducing Tillage: Minimizing soil disturbance prevents erosion and leaving the roots of last year’s residue intact helps maintain soil structure, improving water infiltration and root penetration.
Cover Crops: Planting cover crops during off-season periods helps reduce soil erosion, nourish soil microbes, and increase water infiltration by protecting the soil from compaction.
Rotating Crops: Crop rotation promotes a diverse root system, which can improve soil structure, organic matter content, and nutrient cycling.
Buffer Strips: Establishing buffer strips of vegetation along waterways can trap sediments and nutrients before they enter water bodies, improving water quality.
Contour Farming: Plowing along the contour lines of a field can reduce runoff and soil erosion, enhancing water retention.
Healthy soils not only support efficient water use but also enhance the resilience of agricultural systems to drought and other climate challenges. And according to the University of Illinois Extension, implementing these practices can significantly reduce nitrogen loads from drained cropland, thereby improving water quality in agricultural regions.
Conclusion
Efficient water management is essential to promote irrigation sustainability, water quality, healthy growth, and higher yields. By adopting efficient irrigation practices, implementing conservation measures to improve soil health, and utilizing modern tools, farmers can reduce the amount of water and energy needed for irrigation, lowering operational costs and increasing ROI. As we face increasing water challenges, these best practices offer a pathway to a more sustainable and productive agricultural future, significantly contributing to the preservation of this vital resource.
If you’ve been thinking about trying or expanding a conservation practice, such as reduced tillage, implementing a cover crop, or adding a crop rotation, enrollment in the Soil and Water Outcomes Fund is open for 2024. By enrolling your acres with SWOF, you’ll receive agronomic support and earn financial incentives for the environmental outcomes of your on-farm conservation efforts. Get started today by signing up for a free estimate!
Tim Huggins
Program Manager
In his role as Program Manager, Tim Huggins leads field work in SWOF’s southern territories and oversees farmer contracting for the U.S. Climate Smart Cotton Program, a collaboration between the U.S. Cotton Trust Protocol (USCTP) and SWOF to advance the adoption of climate-smart practices amongst cotton farmers. He graduated from Delta State University where he studied environmental science with a concentration in wildlife management. Tim has held previous roles with Trust for Tomorrow, Delta Farmers Advocating Resource Management (Delta F.A.R.M.), and Delta Wildlife.
Sources:
Christianson, Laura E., Jane Frankenberger, Chris Hay, Matt Helmers, and Gary Sands. "Ten Ways to Reduce Nitrogen Loads from Drained Cropland in the Midwest." Pub. C1400, University of Illinois Extension, 2016.
Little, Jane Braxton. "Saving a Vital U.S. Water Source: The Ogallala Aquifer." Scientific American.
Sharma, Vasudha. "Soil Moisture Sensors for Irrigation Scheduling." University of Minnesota Extension.
Yost, Matt, Niel Allen, Grant Cardon, and Earl Creech. "4R's of Irrigation Management." Utah State University.