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Eyes Opening
“This is a serious issue,” explained Dr. Chris Henry, Associate Professor and Water
Management Engineer for the University of Arkansas, as he addressed a group and
provided information for saving water while growing a healthy crop.
Photo by John LaRose, Jr.
Road To Solving Water Issues Begins With MIRI
BETTY VALLE GEGG-NAEGER
MidAmerica Farmer Grower
BATON ROUGE, LA.
Farmers attending the 20th Annual National Conservation Systems Cotton & Rice Conference here recently learned about the decline in ground water and its effects on crop irrigation now and in the future. Dr. Chris Henry, Associate Professor and Water Management Engineer for the University of Arkansas, addressed the group and provided information for saving water while growing a healthy crop.
“This is a serious issue,” he warned. According to the recent 2014 Arkansas Water Plan if no action is taken, over 80 percent of crop acres will be without groundwater by 2050. The need to reduce this decline is very obvious.
Rice requires 32 acre-inches of water annually, but by using Multiple Inlet Rice Irrigation (MIRI) a water savings can be obtained. MIRI also has been shown to increase yields by five to 10 bushels per acre over cascade fields.
“MIRI reduces the cold water effect on the first levee, reduces total water use by 25 percent, allows for the implementation of alternating wetting and drying, and a faster flood time than the traditional cascade system,” Henry said. “Being able to quickly flood a field is beneficial for being able to get the flood established for water management as well as weed control and ensuring fertilizer efficiency.”
Both the Division of Agriculture and Delta Plastics promote MIRI and offer support for the use of the system. To effectively implement Natural Resource Conservation Service (NRCS) Irrigation Water Management Plans, MIRI should be used. NRCS also often provides financial assistance to growers for participating in alternate wetting and drying or carbon credit programs.
“All in all, there’s more than $100 an acre available through incentive programs, yield advantages and pumping cost savings,” said Henry.
Two-and-a-half inch blue gates and a plan are required to use MIRI successfully. The blue gates allow for a wide range of flow and for the irrigator to adjust and balance the flow to each levee so the field floods evenly.
“Do not use the ‘piranha puncher’ in a flooded rice field,” Henry warns. “The commonly used hand tool may be eating through profits because if holes are punched with no way to adjust them, some levees will cascade over others negating the benefits of MIRI.”
Effective implementation of MIRI should have water going over levee gates only when more than an inch of rainfall has occurred, and levee gates need to be set higher than they would be for cascade irrigation since these are overflow devices when MIRI is used. Often, MIRI irrigators no longer put in levee gates, using instead a simple overflow to further reduce costs and labor. With proper use, MIRI eliminates the in-season chore of wading through rice fields to adjust levee spills.
Dr. Chris Henry, Dr. Dharmendra Saraswat, and Jace McPherson developed a mobile application, named Rice Irrigation, to promote the implementation of MIRI. The application can help users measure levee and field areas and determine gate settings needed to deliver the water efficiently to rice fields. The application operates on Android and iOS. Search for “Rice Irrigation” in the Apple App Store or in the Google play store on android devices. Data is stored on a server so users can access that from any device. It offers the ability to upload GPS levee files and swap between multiple years of aerial photography.
Further addressing the seriousness of the aquifer’s depletion in a telephone interview, Henry said: “We would have to cut our irrigation ground water use by about half to stop the depletion of the aquifer. While we do not have all of the answers, with easy to implement conservation and management, we are able to make a big move towards reducing the overdraft. Some farmers are really pushing it and have obtained as much as a 40 percent reduction in water usage while maintaining yields. The potential is there, but you have to manage water like other crop inputs. Your future profitability depends on it.” ∆
BETTY VALLE GEGG-NAEGER: Senior Staff Writer, MidAmerica Farmer Grower
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