V. Todd Miller

Salting the soil was a medieval practice by conquerors to discourage the subjugated from rebuilding their sacked cities by purposefully harming their food sources.

Today, LSU AgCenter researchers at the Macon Ridge Research Station assist producers battling high salt content in a resource they can’t live without — irrigation water.

Occupying 815 acres near Winnsboro, the Macon Ridge Research Station came to fruition in the 1950s when farmers in northeast Louisiana required research on the drought-prone soil conditions west of the Mississippi River Delta. Since then, AgCenter researchers like plant pathologist Trey Price and soil fertility specialist Rasel Parvej have been finding solutions on many fronts for area farmers and home gardeners alike.

“The Macon Ridge is a unique production area in the state,” Price said. “A couple of things that make it a challenge are salty irrigation water along with drought-prone soils. Many producers have these issues on their farms.”

Price says it’s been a problem at the station for the entire 18 years he’s worked there. Certain areas within the Mississippi River Alluvial Aquifer sit over geological formations containing different dissolved solids commonly referred to as salts. The station, because of its location and some depletion of groundwater resources, has seen increased salt content in irrigation water over time. This is a concern, particularly in soybean and rice production as these crops can be sensitive to saline conditions.

“We are able to screen soybean and rice varieties for tolerance to the salty conditions in northeast Louisiana,” Price said. “It is important for producers to have their well water tested because some irrigation is salty enough to kill certain varieties.”

Price studies diseases in corn, cotton, grain sorghum, peanuts, soybeans, wheat, oats and rice and develops integrated management solutions for all eight crops. He also works closely with crop breeders and specialists in variety development. Row crop production is the biggest industry in northeast Louisiana, where farmers produce most of the corn, cotton and soybeans in the state along with 20% to 25% of the rice. The research at Macon Ridge is always geared toward improving the bottom line of Louisiana farmers, but without irrigation it would all be for naught.

“It’s a huge challenge for crops at the Macon Ridge station if you don’t get rain,” Price said. “Between droughts and saltwater irrigation, we fill a niche for growers on the Macon Ridge and throughout the state.”

Price and his team work extensively with breeders in variety development adapted to northeast Louisiana. The breeders along with Price evaluate material in the field, providing a unique location to address numerous concerns.

“For growers it’s always yield, yield, yield, but disease resistance also is important,” said Price. “We’re able to provide information for growers on an annual basis for specific diseases that are problems on their farms. We also have specialized variety trials in high-disease pressure fields as well as inoculated trials to screen for resistance to specific diseases.”

Price’s colleague, soil fertility specialist Rasel Parvej, moved to the U.S. from Bangladesh in 2012, attending the University of Arkansas for his doctorate, then Virginia Tech as a postdoctoral associate. He continued his postdoctoral research at Iowa State University before joining the AgCenter in October 2019.

“It really felt like coming back home because all of my Ph.D. research was beside the Mississippi Delta, working in a similar environment,” Parvej said. “My main focus is to offer and develop optimum fertilizer recommendations based on soil-test nutrient concentrations to row crop producers throughout Louisiana.”

Parvej also represents the AgCenter as part of national initiative of Fertilizer Recommendation Support Tool (FRST) with the goal of providing fertilizer recommendations by clear and consistent interpretation of soil-test nutrient concentrations.

“This removes the political and institutional bias,” Parvej said. “Within a few years through this FRST initiative, we will be able to develop fertilizer recommendations for a large geographical region similar in soil types, production systems and climate.”

As the resident coordinator of variety testing for corn, soybeans, cotton and grain sorghum at Macon Ridge, Parvej provides recommendations and soil test interpretations for the farming community as well as home gardeners, helping growers understand the next steps.

“Most row crop producers get their fertilizer recommendations from private labs and their recommended fertilizer rates often are much higher than AgCenter recommendations,” Parvej said. “I always encourage producers to consult with AgCenter extension agents or contact me directly for making decisions and choosing the best fertilizer rate for their farms. In most cases, producers can save a significant amount of fertilizer, cost and input, which helps increase profit and reduce off-site environmental impacts from over fertilization.”

Macon Ridge soil is silt loam, which is good for production overall, but it doesn’t hold that much water due mainly to less organic matter content. While the heavy rainfall Louisiana has encountered this year has caused issues for many growers, Parvej said that it has been more of a blessing than a curse at Macon Ridge.

“Soybeans are especially sensitive to the salty irrigation water here,” said Parvej. “Luckily, with the rain we’ve had this year, we haven’t had to irrigate as much, which has been good for local farmers and gardeners.”

V. Todd Miller is an assistant communication specialist and assistant editor of Louisiana Agriculture.

(This article appears in the fall 2021 issue of Louisiana Agriculture.)

Occupying 815 acres near Winnsboro, Louisiana, the Macon Ridge Research Station came to fruition in the 1950s when farmers in northeast Louisiana required research on the drought-prone soil conditions west of the Mississippi River Delta. Photo by Randy LaBauve

LSU AgCenter researchers at the Macon Ridge Research Station assist producers who are battling high salt content in a resource they can’t live without — irrigation water. Photo by Randy LaBauve

Ponds at the Macon Ridge Research Station near Winnsboro, Louisiana. Photo by Randy LaBauve