Writer: Kay Ledbetter, 806-677-5608, skledbetter@ag.tamu.edu
Contact: Dr. Curtis Adams, 940-552-9941, Curtis.Adams@ag.tamu.edu
Dr. Calvin Trostle, 806-746-6101, ctrostle@ag.tamu.edu

VERNON – When a Texas Rolling Plains guar producer found himself to be potentially out of compliance with government guidelines, he turned to Texas A&M AgriLife to help get the guidelines updated.

Guar has been grown in Texas for more than a century and is becoming more attractive to producers because of its drought tolerance and relatively low water use, said Dr. Curtis Adams, Texas A&M AgriLife Research crop physiologist in Vernon.

guar plants
Guar is gaining in interest as a rotational crop. (Texas A&M AgriLife photo by Dr. Curtis Adams)

“Guar being a legume and adapted to the region’s semi-arid dryland agriculture is increasing producer interest,” said Dr. Calvin Trostle, a Texas A&M AgriLife Extension Service agronomist in Lubbock and long-time investigator of guar.

“There are few legumes that are adapted in this type of environment,” Trostle said. “That is why this latest decision is important; to give producers another rotational crop, one that can provide nitrogen to the soil in an area it doesn’t rain a lot.”

Together Adams and Trostle provided updated guar residue measurements and data demonstrating reduced soil erosion due to modern reduced-till soil management. This prompted the U.S. Department of Agriculture-Natural Resource Conservation Service, or NRCS, to revise their guidelines on using guar in a crop rotation.

Initially, NRCS classified guar as a low-residue crop, and therefore under USDA-Farm Service Agency guidelines, grower Guy Spears was not allowed to plant it in rotation with other crops considered low residue under his farm’s conservation plan.

The high-residue parameters are required at a certain frequency in NRCS conservation plans on “highly erodible land,” or HEL. Being out of compliance would make farmers ineligible for a variety of government benefits, including government-sponsored crop insurance, Adams said.

Spears began working with Trostle and Kelly Lindsey, the local NRCS county director, to push for a change. Then Adams was asked to provide on-the-ground data that, combined with Trostle’s ongoing research, determined guar residue was sufficient to meet NRCS criteria. This prompted a review and update of NRCS policy, which would regard guar as a residue equivalence, comparable to a “high residue” crop.

Fred Schrank, NRCS agronomist in Weatherford, said compliance isn’t automatic. To know if a producer’s plan will be in compliance will require a field-by-field determination. Each producer considering the inclusion of guar must check their original plan or revise the plan.

“The Vernon field office and I will be utilizing the Integrated Erosion Tool, or IET, templates developed to streamline assistance for planning HEL fields and farmers decisions,” Schrank said. “We will work with you and other farmers to keep compliance, production and conservation concerns achievable in these matters.”

“Thanks to AgriLife Research in Vernon and the measurements provided, which prompted the NRCS to re-examine their original documentation from 1985,” Spears said. “I have been notified that after reconsideration, NRCS has ruled a cotton/guar rotation or a continuous guar rotation will be in compliance if a grower is using minimum, no-till or strip till. Also, every grower will have to update their plan accordingly.”

Spears said he contacted NRCS officials not only for himself, but for owners of the thousands of acres of farmland designated as highly erodible land that could benefit from the wind erosion protection and soil–building properties guar provides as a rotational crop.

The NRCS was relying on guar residue data from 1985, post tillage, though management practices have changed since then, Adams said. Research showing reduction in erosion with no-till and minimum-till soil management, such as that done by Dr. Paul DeLaune, AgriLife Research environmental soil scientist at Vernon, and others was incorporated into the altered policy of NRCS. Management also includes row spacing of 20 inches or less, which is required to provide adequate crop residue coverage.

Adams said his lab took residue measurements on harvested guar fields and did visual scoring of percent ground cover on the Spears’ farm to establish the crop’s residue levels.

Adams said he measured a residue concentration at about 2.5 tons per acre.

“This level of cover is less than you would commonly see with grain crops, like corn and sorghum, but it is greater than many broadleaf crops, like cotton,” he said. “On the guar field, we noted that the soil was stable, with no evidence of erosion.”

Adams, Trostle and others are working on multiple federally funded projects aimed at providing more information for producers on guar in relation to agronomics, rotation and other issues.

“The fact is times change,” Spears said. “What is reassuring as a grower is having Texas A&M, the FSA and NRCS all working together to fix a problem for all of the farmers and leading us in the right direction.”

More information on guar can be found at https://lubbock.tamu.edu/programs/crops/other-field-crops/guar/.