Consider Improving Irrigation Management And Scheduling Practices Before The Dry Season

DR. STACIA L. DAVIS

BOSSIER CITY, LA.
   Though it’s difficult to focus on irrigation with the considerable amount of rainfall occurring now, this is the perfect time to address improvements to your current irrigation management practices. Proper irrigation scheduling – knowing when to pull the trigger – is extremely important to maximize yield and profits. Irrigating too much will negatively impact the crop due to leached nutrients, erosion, and creating surface runoff that carry pesticides, herbicides, and fertilizers off the field. Limiting over-irrigation has the potential to address concerns over diminishing water resources, increasing environmental regulation, and rising costs of irrigating crops.
   Maintenance and installation recommendations are based on the type of irrigation delivery system. For furrow irrigation, consider running PHAUCET or Pipe Planner (Delta Plastics, Little Rock, AR) to select the hole sizes that should be punched into the lay-flat tubing. Selecting the proper hole sizes allows for adequate pressure through the system and uniform watering along the furrows. Information such as the discharge flow rate from the riser and the elevations along the lay-flat tubing pad is required for an accurate design. For center pivot systems, the nozzle package should be checked for adequate application this season and that the entire system is in proper working condition. It is extremely important to verify electrical grounding on these systems prior to performing maintenance. Pumps associated with all systems should be tested for efficiency since energy is the most significant cost to irrigating.
   Technologies have become a popular and more affordable method to assist producers in making irrigation decisions. Current available technologies for irrigation scheduling include weather-based scheduling systems and soil moisture sensors. Both technologies can provide valuable information concerning field conditions and, depending on the level of control given to the technology, can determine irrigation schedules such as when to start irrigating and how long it should run. In most situations, the use of smart technologies requires an integrated approach between the technology and the producer for overall efficient irrigation.
Selecting between weather and soil moisture technologies is primarily up to the preferences of the producer. Soil moisture sensors are generally small and can be cost effective, but measurements are typically taken from a single location and extrapolated to large areas. In situations of terrain restrictions or inconvenient sensor installation, a weather-based technology such as a full or partial weather station may be a better option since it can be installed away from the fields.
   Surge valves are another technology that can improve efficiency in furrow-irrigated applications. This device is installed so that an irrigation set is split into two smaller sets. Irrigation is applied in relatively short cycles that alternate between the two sides. This allows time for the water to soak into the soil before another cycle occurs. Surge valves are best applied on fields with unusually long furrows and on soils with poor infiltration characteristics.
   The Smart Technologies for Agricultural Management and Production (STAMP) program was established in 2014 to include research and extension activities concerning technologies in agriculture. For more information on irrigation technologies or STAMP, please contact Dr. Stacia Davis at sdavis@agcenter.lsu.edu or your local ANR extension agent. ∆
   DR. STACIA L. DAVIS: Assistant Professor/Irrigation Engineer, LSU AgCenter