John Branch, Chaney, John A., Daniels, Glen E. | 4/19/2005 10:29:19 PM
VIDALIA – Louisiana is blessed with abundant rainfall and large supplies of surface water, but the groundwater supplies have been declining in three major aquifers.
Now, farmers are looking for more efficient ways irrigate their crops.
"The need to irrigate crops is important to all farmers and essential for rice farmers," said LSU AgCenter irrigation specialist Dr. Bill Branch, adding, "We need to find more efficient and economical methods to manage the water resources."
The costs of irrigation on a farm depend on the source of water, the slope of the land, the quality of the water, the soil type and the cultural practices used on the farm.
Branch said the purpose of an irrigation workshop last week (May 26) was to provide an opportunity for farmers and water resource professionals to learn about irrigation research being conducted here and in other states such as Arizona, Arkansas and Mississippi.
The workshop also gave participants to tour precision-leveled fields that incorporate a technique known as level-basin irrigation at Angelina Plantation – a 26,000 acre rice, soybean, grain sorghum, wheat and oat farm near Monterey.
"We precision-leveled 9,000 acres of the rice and soybean land and built levies, roads, ditches and installed an irrigation system for each 80-acre field for a cost of $402 per acre," said Lee Bean, general manager of Angelina Plantation.
In turn, those improvements allow use of a system known as level-basin irrigation, which helps reduce the amount of irrigation water needed for the crops and the labor to maintain a flood on the rice, he said.
When flooding a rice field, "We pump water on the field to establish a flood and turn the pump off," Bean explained, continuing, "It is like putting water in a pond – the fields stay flooded until the water is drained from the field."
The fields have ditches on three sides, which help to quickly cover the field with irrigation water or drain excess water from the field following a rain.
"There is little need for a shovel in a level-basin field, and water levels can be checked at any location in the field," Bean said. "This saves a lot of time and labor."
Bean said their experience shows the total amount of water needed to produce rice in a season can be reduced using level-basin techniques rather than conventional rice irrigation methods.
"Successful farming is a game of pennies," Bean said. "And farmers must be efficient in all segments of their business."
LSU AgCenter county agent Glen Daniels of Concordia Parish, who helped to organize the workshop, said farmers want to know when to irrigate their cotton, corn and soybeans. He said it is important to irrigate clay soils like those found in the area before they crack too severely – especially early in the season.
In addition to touring Angelina and seeing level-basin irrigation in use there, professionals from other states were invited to share their knowledge about irrigation studies and technologies being used in other parts of the country.
Bert Clemmens, director of the U.S. Water Conservation Laboratory in Phoenix, Ariz., said level-basin irrigation in Arizona reduces water use up to 40 percent, cuts labor by $18 per acre and increases yield 15 percent over conventional irrigation systems.
Moving to another type of irrigation, Wayne Smith, an engineer for the University of Arkansas, said the use of multiple-inlet irrigation systems in rice is an effective system to use on land with a gradual slope.
In multiple-inlet systems, water is transported by a pump through polyethylene tubing and discharged through holes punched in the wall of the tubing.
A study of the multiple-inlet rice irrigation system by the University of Arkansas indicated it reduces water use by 26 percent, cuts labor by 30 percent and increases rice production by 3.8 percent over conventional irrigation systems, according to Smith.
"This system is especially good for growers with limited water supplies – but it helps any grower cut water use and input costs," Smith said.
On another topic, Jim Thomas, an engineer from Mississippi State University, explained how farmers can flood a field and then raise the levee gate and capture rainfall in a rice field to use in the irrigation process.
In an experiment last year, Smith said they were able to maintain yields but cut water use in one field by 10 inches through this type of intermittent irrigation.
"This is an excellent way to study and learn about irrigation technologies that have been tried in other states but are new to us," the LSU AgCenter’s Branch said of the workshop.
For more information on a variety of issues related to agriculture and natural resources, home lawns and gardening, food, nutrition, family life and more, go to www.lsuagcenter.com or visit your parish LSU AgCenter Extension office.