Soil health field day highlights AgCenter research

OLIVIA MCCLURE

ST. JOSEPH, LOUISIANA

An old adage says a picture is worth a thousand words. For Dennis Burns, the coordinator of the LSU AgCenter Northeast Research Station, a single photo sums up something he and several colleagues have been studying extensively: the benefits of conservation methods such as planting a cover crop in the offseason.

“I took a picture last year,” Burns recalled at a recent field day at the station. “We had some ground that was prepared for the winter and sprayed with a herbicide. The water coming out of the field, out of the culvert was brown. There was a cover crop field right down the road, and the water coming out of there was clear.”

Cover crops help stop erosion, and many farmers have already implemented them to protect their soil, add nutrients to it, break up compacted areas and ultimately grow a better cash crop.

From cereal rye to hairy vetch to crimson clover, many options are available. AgCenter researchers are gathering data to help farmers make more informed decisions about choosing and growing them as the practice gains popularity.

“Where we have conventional tillage and no covers, you can see the amount of sediment that’s being lost off of those fields after rainfall or an irrigation event,” said AgCenter soil scientist Lisa Fultz. “That’s been one of the big things we’ve taken home — that having that groundcover has a lot of benefits to the soil systems. It helps keep them in place and adds organic matter and nutrients to them as well.”

The biomass created by cover crops is what provides that organic matter and nutrient content to the soil. Fultz is working to determine whether farmers can scale back current recommended seeding rates and still achieve the same amount of biomass — something that would represent a significant cost savings. It seems to be a viable move with some cover crops, but not all, she said.

Her graduate student, Andres Carrillo, spoke about using digital technologies from satellite imagery, drones and handheld sensors, to estimate the amount of biomass produced by cover crops. The goal is to couple biomass data with nutrient content to estimate nutrient release and availability to later cash crops.

AgCenter soil scientist Brenda Tubaña is quantifying specific amounts of nitrogen, phosphorous, potassium and sulfur that various cover crops provide.

“This is very useful for cutting down on unnecessary fertilizer applications while maintaining yield,” she said.

Tubaña is evaluating other strategies for scaling back fertilizer applications while preserving yields — which benefits both the environment and farmers’ income.

“We are taking care of the soil, and we are taking care of the productivity of the field,” she said.

Cover crops also can help reduce herbicide use. Burns has been studying rolling and crimping covers when it’s time to plant a cash crop. Roller-crimper machines flatten the cover crop, creating a mat that naturally suppresses weed growth.

“It’s just like you using a mulch material,” said postdoctoral researcher Peters Egbedi, who also is examining the practice.

Many others from the AgCenter spoke at the field day, including economist Naveen Adusumilli, agent James Hendrix, weed scientist Donnie Miller, corn and cotton specialist Matt Foster and Louisiana Master Farmer Program coordinator Donna Gentry.

Matt Lee, LSU vice president for agriculture and dean of the College of Agriculture, praised the scientists’ work and said it is vital to the mission of the university.

The AgCenter and college have a critical role to play in LSU President William F. Tate IV’s Scholarship First Agenda, which names agriculture, biomedical, coast, defense and energy as priorities, Lee said. 

The research presented at the field day is an example of how improving agriculture can positively affect many other areas, Lee said.

“The work that we do at the AgCenter and the College of Agriculture actually ties across all of those areas in various ways,” he said, “so that makes us very well positioned to remain central to what it is that the LSU System does.”

Burns encouraged farmers to be active in helping shape AgCenter research efforts.

“We do all kinds of things here with a lot of different crops,” he said. “Anything you can think about that you might want us to look at, let us know. That’s how we get ideas a lot of times.”

Some of the work discussed at the event is part of a $1.7 million grant project funded by the Patrick F. Taylor Foundation that aims to identify ways to reduce agricultural runoff. The grant was awarded in 2019 and recently was renewed for another four years.

Others on the program are working on projects funded by the Louisiana Soybean and Grain Research and Promotion Board and a multistate grant from the U.S. Department of Agriculture National Institute of Food and Agriculture. ∆

OLIVIA MCCLURE: LSU AgCenter