Cropping System Archives - Department of Soil and Crop Sciences

Regenerative agriculture evaluation gets underway in Texas and Oklahoma

3Dec

Written by: Kay Ledbetter

From carbon sequestration to greenhouse gas emissions to cover crops, this fall a team of Texas A&M AgriLife faculty and others will begin evaluating the impacts of regenerative agriculture in semi-arid ecoregions in Texas and Oklahoma.

A small white piece of equipment sits in a field - it will measure greenhouse gas. A cart on bicycle tires hauls the equipment

Soil carbon capture and greenhouse gas emissions will be measured in the field in the sustainable agriculture study. (Texas A&M AgriLife photo by Katie Lewis)

The Texas A&M AgriLife-led team aims to further understand and encourage the widespread adoption of regenerative practices that increase agricultural production and profitability while reducing agriculture’s environmental footprint.

Katie Lewis, Ph.D., Texas A&M AgriLife Research soil scientist, Lubbock, who will lead the project, said relationships between soil health and implementation of regenerative practices, agricultural production, climate change and regional economics are complex and poorly understood, particularly in the Southern Great Plains.

Without this understanding, the adoption of regenerative practices across the region and in similar ecoregions will remain limited. This will increase the vulnerability of agricultural production to climate change and continued depletion of water resources while passing up opportunities for carbon sequestration, enhanced agricultural production and greater agricultural resiliency.

The five-year “Sustainable Agricultural Intensification and Enhancement Through the Utilization of Regenerative Agricultural Management Practices” project has been funded by a $10 million grant from the U.S. Department of Agriculture National Institute of Food and Agriculture.

“What’s so exciting about this research is it will be the first regenerative agriculture project to cover this large of an area across both Texas and Oklahoma,” Lewis said. “With carbon being such a hot topic, we want to take a closer look at carbon sequestration – what is being captured and what is being lost through greenhouse gas emissions.”

Region-specific research to address semi-arid issues

Cattle graze is a field of corn growing in wheat stalks that were left to biodegrade

The study will look at implementing and grazing cover crops during fallow periods to evaluate environmental, economic and agronomic sustainability of regenerative agricultural systems.. (Texas A&M AgriLife photo by Paul DeLaune)

Many times, talk of cover crops or regenerative agriculture in the U.S. refers to areas with 40 to 50 inches of rain per year. This amount of rain is not what typically occurs in Texas and Oklahoma, one of the largest cotton and livestock production regions in the nation.

But little research has been conducted to better understand how regenerative agricultural practices, when incorporated into a larger production system, perform under the varying precipitation of these regions.

“We want this to be as real as possible,” Lewis said. “There’s just so much information that is not suited for our regions. This project is going to result in the optimization of practices for semi-arid regions that will result in profitable and sustainable practices.”

The team’s approach will look at not just one practice in isolation but the entire agricultural production system that includes cover crops, crop rotations, grazing and other management techniques that can work on a farm-by-farm situation.

“Long-term, region-specific research, especially in semi-arid regions, is needed to better understand regenerative practices and the effects on soil health and water use in cotton agroecosystems,” Lewis said.

Determining ways to alleviate the risk involved in raising crops as well as protecting the environment and natural resources are among the main goals of the project. The project encompasses short-term, medium-term and long-term goals, which will enable continued improvement even after the project ends.

Two men stand beside a flume and gearbox at the edge of a field

Texas A&M AgriLife researchers Paul DeLaune and Srini Ale look at an edge-of-field automatic water sampler near Vernon that will evaluate the effects of soil health promoting practices. (Texas A&M AgriLife photo by Kay Ledbetter)

“We plan to identify the immediate challenges on the ground and reduce the risk that is associated with change when it comes to farming practices,” Lewis said. “It’s nothing but change from one year to the next in farming, but helping to alleviate that risk is one of our main goals as well as to protect the environment and natural resources.”

More than just a research project
Equally important as determining the most efficient agricultural practices, Lewis said, is the need for further outreach and education for producers and landowners in these regions. Part of the project is a careful examination of how producers interpret information the team presents.

“This is not just a research-based project,” Lewis said. “It includes research, extension outreach, education – there’s so much misinformation that is published and available to the general public.”

Meeting the short-, medium- and long-term goals of the project involves working directly with producers, she said, but it also includes reaching out to students and consumers.

“We wanted to be able to start young with our college-age students and the general public and let them make more informed decisions when it comes to things that impact farmers and rural communities.”

field showing crop rotation wheat and fallow

The wheat, cotton, fallow rotation will be studied to determine the impacts of different management strategies on soil properties and crop performance. (Texas A&M AgriLife photo by Paul DeLaune)

The team’s approach to Extension outreach and education will go beyond that of many traditional projects, which rely on field days, workshops and farmers asking specific questions when they encounter a problem.

“We’re going to have a hands-on approach with the creation of a Master Soil Steward Program that will allow farmers to see results on their farm,” Lewis said. “It will be much more personal, and we’ll be able to talk with them on a farm-by-farm basis.”

Additionally, undergraduate and graduate courses will be established in regenerative agriculture at Oklahoma State University, Texas A&M University, Texas Tech University and West Texas A&M University utilizing data collected from this research.

Conducting the research, education and outreach
Within the Texas A&M College of Agriculture and Life Sciences, the project will include team members from the Department of Soil and Crop Sciences, Department of Agricultural Economics, Department of Animal Science and Department of Biological and Agricultural Engineering, as well as the Texas Water Resources Institute. In addition to the Texas A&M flagship campus, these individuals are located at Texas A&M AgriLife Research and Extension Centers in Lubbock, Amarillo, Vernon and Overton and represent AgriLife Research and Texas A&M AgriLife Extension Service.

Additionally, team members represent the Soil Health Institute, Morrisville, North Carolina; Texas Tech University, Lubbock; West Texas A&M University, Canyon; Oklahoma State University, Stillwater, and Oklahoma Panhandle Research and Extension Center, Goodwell; and the Office of Education, Innovation and Evaluation, Kansas State University, Manhattan, Kansas.

The Team
Project Director:
Katie Lewis, Ph.D., AgriLife Research soil scientist, Lubbock.
Co-Project Directors:
Allen Berthold, Ph.D., Texas Water Resources Institute assistant director, Bryan-College Station.
Kevin Wagner, Ph.D., Oklahoma Water Resources Center director, Oklahoma State.
Jourdan Bell, Ph.D., AgriLife Extension agronomist, Amarillo.
Paul DeLaune, Ph.D., AgriLife Research soil scientist, Vernon.
Donna McCallister, Ph.D., Texas Tech University assistant professor, Lubbock.
Co-Investigators:
Ali Mirchi, Ph.D., assistant professor of water, Oklahoma State.
Alexandre Caldeira Rocateli, Ph.D., Extension forage systems specialist, Oklahoma State.
Bruce McCarl, Ph.D., AgriLife Extension agricultural economist, Bryan-College Station.
Dianna Bagnall, Ph.D., Soil Health Institute research soil scientist, Morrisville, North Carolina.
Wayne Keeling, Ph.D., AgriLife Extension cropping systems and weed specialist, Lubbock.
Gerald Smith, Ph.D., AgriLife Research plant breeder, Overton.
Monte Rouquette, Ph.D., AgriLife Research forage physiologist, Overton.
Jason Smith, Ph.D., AgriLife Extension beef cattle specialist, Amarillo.
Terry Gentry, Ph.D., AgriLife Research soil and aquatic microbiologist, Bryan-College Station.
Sumit Sharma, Ph.D., Extension irrigation management specialist, Goodwell, Oklahoma.
Briana Wyatt, Ph.D., assistant professor in soil science, Bryan-College Station.
Lucas Gregory, Ph.D., Texas Water Resources Institute assistant director, Bryan-College Station.
Jason Warren, Ph.D., soil conservation Extension specialist, Oklahoma State.
Srinivasulu Ale, Ph.D., AgriLife Research geospatial hydrologist, Vernon.
Murilo Maeda, Ph.D., AgriLife Extension cotton specialist, Lubbock.
Andrea Jilling, Ph.D., assistant professor in environmental soil chemistry, Oklahoma State.
Seth Byrd, Ph.D., Extension cotton specialist, Oklahoma State.
Bill Pinchak, Ph.D., AgriLife Research animal nutritionist, Vernon.
Emi Kimura, Ph.D., AgriLife Extension agronomist, Vernon.
Bridget Guerrero, Ph.D., agricultural economics/business associate professor, West Texas A&M.
Will Keeling, AgriLife Extension risk management program specialist, Lubbock
Cindi Dunn, director, Office of Education, Innovation and Evaluation, Kansas State

More mature cover crops help retain moisture longer

25Oct

By: Kay Ledbetter

Often producers planting cover crops are worried about moisture use, but more important is the longevity of the crop residue and its beneficial results, said a Texas A&M AgriLife Research scientist.

Dr. Paul DeLaune, an AgriLife Research environmental soil scientist at Vernon, said when he talks about the residue management of cover crops, one question he always gets concerns termination timing and the use of soil moisture by the cover crop.

Early cover crop termination can result in residue that rapidly degrades or blows away.

Cover crops are designed to keep soil from blowing and improve soil quality. DeLaune has included Austrian winter field pea, hairy vetch, crimson clover, wheat, rye, turnips and radishes as cover crops in the various studies.

“We use neutron probes here to monitor soil moisture year-round, and yes, the cover crop does use soil moisture,” he said. “But one thing we’ve found is that soil moisture is quickly recharged and your crop is back to status quo if you get a rain between termination and the planting of your cotton.”

This information is based on eight different cover crop studies by AgriLife Research in the Rolling Plains where soil moisture is monitored throughout the year, some continuously since 2012, he said, discussing the studies at the recent Rolling Plains Summer Field Day in Chillicothe.

More important, he said, is the termination timing of that cover crop. In comparing two different termination timings utilizing a wheat cover crop, he said the duration of the residue is increased with the maturity of the wheat.

“I like to let it go ahead and mature out to about 50 percent heading or so, and then plant cotton four to six weeks after termination,” DeLaune said. “This year, we had to terminate a little earlier due to a drift issue – mid-March versus toward the end of April.

“What we determined is if you terminate too early, you’re not going to have lasting residue. The residue in a vegetative stage degrades very rapidly. If you can allow wheat to reach heading, you can see lasting residue for about 18 months.”

So for those producers who are working with a cover crop, his advice is to consider delaying termination timing to ensure it results in lasting residue.

“Your soil moisture will be replenished, especially if it is on irrigated cotton, and it will pay off in the long term to build up your soil organic matter in your system,” DeLaune said. “It will cover your soil and protect your soil much longer.

“Although soil organic matter is slow to build up in our environments, we have seen more immediate impacts off cover crops on soil physical properties such as soil strength and infiltration,” he said. “Within the Rolling Plains, we have not observed depleted soil moisture behind cover crops during wheat and cotton growing seasons in dryland cropping systems.”

DeLaune said he understands there is greater risk in dryland systems and drier environments moving further west. However, Dr. Katie Lewis, AgriLife Research soil scientist at Lubbock, has noted the same trends in irrigated cotton systems at Lamesa.

cotton field with heavy cover crop residue

Waiting to terminate a cover crop leaves lasting residue.

Both locations will continue to evaluate cover crops, he said.

Guar, wheat integration focus of new study

18Sep

Writer: Kay Ledbetter, 806-77-5608, skledbetter@ag.tamu.edu
Contacts: Dr. Curtis Adams, 940-552-9941, Curtis.adams@ag.tamu.edu
Dr. Calvin Trostle, 806-746-6101, ctrostle@ag.tamu.edu

A team of scientists from Texas A&M AgriLife and the University of Florida are working to increase and stabilize guar production in the U.S. by testing integration of guar into existing wheat production in the Southern Plains.

The team is funded for the next four years to conduct this work by the U.S. Department of Agriculture’s “Sustainable Agroecosystems: Functions, Processes and Management” grant program.

Guar produces a seed containing galactomannan gum, which is used in many food and industrial applications as a lubricant, binder, thickener and hardener, among other uses.
“Most people don’t know it, but guar affects our lives every day,” said Dr. Curtis Adams, Texas A&M AgriLife Research crop physiologist in Vernon. “Guar gum is in many of the foods we eat, it’s in products we use in our homes, it’s used to extract oil and gas from the ground.”

Guar is being studied in rotation with wheat in the Vernon and Lubbock areas as part of a new Texas A&M AgriLife research project. (Texas A&M AgriLife photo by Dr. Curtis Adams)

In recent years, Adams said, demand for guar gum has increased substantially, and the U.S. is the world’s largest consumer. In 2011, the U.S. Department of Agriculture reported the U.S. imported $1.1 billion in guar.

Guar is a legume, which means its roots can associate with Rhizobium bacteria in the soil to convert atmospheric nitrogen into fertilizer for the plant and soil, he said. It’s adapted to the semi-arid conditions of Texas and is among the most drought-tolerant crop plants, with relatively low water use.

“Introducing legumes, especially well-adapted legumes like guar, into our cropping systems provides a potential opportunity to improve soil nitrogen fertility and reduce input costs,” said Dr. Calvin Trostle, Texas A&M AgriLife Extension Service agronomist in Lubbock.

“Despite high guar consumption and benefits the plant can provide in cropping systems, U.S. guar production is unstable and only amounts to a small fraction of the world’s guar supply,” Adams said. “We believe this represents missed economic and environmental opportunities.”

U.S. guar production is centered in the Southern Great Plains region of Texas, though acreage has remained low relative to major crops in the region due to a variety of factors.

“One reason U.S. guar production is low is that guar has typically not had the income potential of cotton, the dominant summer crop in this area,” Adams said. “A lack of crop insurance for guar is another reason, which may be attributed to the lack of development in the industry.”

When guar is grown here, it is usually in cotton systems, and then only when cotton prices are particularly low or as an emergency crop following failed cotton, he said.
“We expect competition with cotton to be an ongoing barrier to guar production for producers,” Adams said. “But, wheat cropping systems, which are left fallow in the summer, may provide another venue for guar.

“Integration of guar into wheat cropping systems has not been rigorously tested. But data gathered by our team showed that wheat planted immediately following guar had far higher productivity than wheat following three other summer crops, including cotton, sesame and sorghum.”

Trostle said the results of published studies on guar and wheat planting dates, water use and other relevant factors also suggest that the crops would complement each other in a combined cropping system.

“We hope this new USDA project will provide useful information on how and why guar should be integrated into wheat cropping systems, helping to boost and stabilize U.S. production of the crop,” Adams said.

Joining Adams and Trostle on the research team are Dr. Srini Ale, geospatial hydrologist, Dr. Seong Park, economist, and Dr. Paul DeLaune, environmental soil scientist, all with AgriLife Research in Vernon, as well as Drs. Gerrit Hoogenboom and Ken Boote, plant modelers from the University of Florida.

In the new project they will test various system management scenarios for integration of guar into wheat systems in Vernon and Lubbock, measuring and simulating impacts of the integration on crop, soil, water and economic factors.

The researchers will identify optimal cropping intensities to enhance productivity and soil nitrogen fertility. In doing so, they said they expect soil organic carbon and rates of microbial activity will increase in wheat-guar systems, an indication of potential improvements in soil health. DeLaune will work on this aspect of the project.

Another core aspect of the project is development of an original Decision Support System for Agrotechnology Transfer, or DSSAT, model for guar to aid in data extrapolation and decision support. Hoogenboom and Boote will be working on development of the DSSAT model, while Ale will be making simulations with the new model.

“Our model will be the first of its kind for guar and will help improve our understanding of guar and how best to utilize the crop,” Ale said. “We expect the model to be used by researchers and policy makers in guar production areas around the world.”

Park will be assessing economic outcomes of the project. The team expects that integrated wheat-guar systems will bring higher proceeds than continuous wheat.

“Ultimately, we want to make producers aware of potential benefits and challenges associated with integrating guar into wheat production systems, benefitting producers and increasing domestic guar production,” Adams said.

Guar producer uses Texas A&M AgriLife support to prompt revisions in NRCS guidelines

12Jul

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 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/.

Interest in alternative crops remains steady

10May

By: Adam Russell
Contact: Dr. Calvin Trostle, 806-746-6101, ctrostle@ag.tamu.edu

Oilseed crops like sunflowers and canola are experiencing lower prices, but it appears overall interest in alternative crops remains steady, said a Texas A&M AgriLife Extension Service expert.

Dr. Calvin Trostle, AgriLife Extension agronomist, Lubbock, said alternative crop options such as sunflowers, sesame, canola and guar remain minor crops, but their viability due to drought and heat tolerance may increase their popularity as market demands rise.

Trostle said there is a large oversupply of confectionary sunflower seeds, which are the edible snack seeds, due to high and even record-breaking national yields per acre the past few years. Oversupply has hurt prices and demand for planted acres this year.

Sunflowers are one of several oilseed crops that have become popular alternatives for producers. This year, sunflower seed prices are lower due to an abundant supply following multiple years of record-breaking harvests. (Texas A&M AgriLife photo)

“One commodity broker in Lubbock typically contracts up to 40,000 acres in the Texas High Plains, but they contracted none this year,” Trostle said. “Regional prices are lower, so this means acres will go elsewhere. Growers don’t plant sunflowers unless they’re under contract, because otherwise there are no assurances there will be anyone to buy their crop.”

Prices are fair at best for oilseed sunflower, and the Texas oilseed acreage is expected to be down to about 35,000 acres from 50,000 acres or more. Planted acres include up to 9,000 acres in the Lower Rio Grande Valley for export to Mexico and about 20,000 acres for bird seed production.

With sesame, current contract acreage is limited to one company, Trostle said. He is uncertain about sesame acreage, but said it appears Texas production could be in the range of 50,000 acres to as much as 100,000 acres. Trostle said there could be some increased export demand from Japan, which recently reduced import regulations on the crop.

A second company is conducting test plantings with new non-shattering varieties to evaluate possible expansion of sesame in West Texas in the near future, he said.

The northern Texas Rolling Plains has some winter canola production. But one canola limitation in the region is the planting window, which closes early in October when some producers have not harvested summer crops like cotton.

Canola offers a rotational crop option to wheat in fields with grassy weeds that would be a potential problem, Trostle said. But canola also requires more management than wheat.
There is current interest in re-examining the spring canola potential on the lower Texas Gulf Coast, Trostle said. This area was a production region for spring canola through the 1980s.

Prices have fallen for another minor oilseed, guar, since the market ballooned in 2013, said Trostle.

Texas guar producers are expected to increase acreage by as much as 30 percent this season, he said. Guar prices continue to be low, but there is great interest in the heat and drought tolerant crop. The U.S. Department of Agriculture is providing $1.2 million across four research grants focused on the crop or in conjunction with other minor crops.

“Guar prices tend to follow petroleum production because it is used in the drilling process,” he said. “There is a huge market for it when drilling is active, and there is interest in it as a food-grade emulsifier. Guar is drought and heat tolerant, so there’s plenty of areas in Texas where it could be a successful crop.”

Study sheds light on nodulation in guar

8Feb

Writer: Kay Ledbetter, 806-677-5608, skledbetter@ag.tamu.edu

Contact: Dr. Curtis Adams, 940-552-9941, Curtis.Adams@ag.tamu.edu

VERNON – Texas A&M AgriLife scientists are conducting several research projects to improve producers’ understanding of guar and the legume’s value to their operations in the Rolling Plains and South Plains.

Guar has been grown in Texas for more than a century, but acreage of the crop in the state is relatively low, said Dr. Curtis Adams, Texas A&M AgriLife Research crop physiologist in Vernon,

Lack of nodulation on guar roots is one of the producer concerns addressed in a recent AgriLife Research study by Adams and Dr. Calvin Trostle, Texas A&M AgriLife Extension Service agronomist in Lubbock, along with Dr. Santanu Thapa, AgriLife Research postdoctoral research associate in Vernon.

Nodulation is the process of forming nodules on the roots of legume plants. Nodules are root structures that legumes make to house bacteria capable of using nitrogen gas from the air to form fertilizer that the plant can use to grow.

Dr. Curtis Adams, Texas A&M AgriLife Research crop physiologist, Vernon, tested the effects of contrasting soils, a sandy loam and a clay loam, and Rhizobium inoculants on nodulation and plant growth in two guar varieties in the greenhouse. (Texas A&M AgriLife photo by Dr. Curtis Adams)

The team conducted a controlled environment study to compare the impact of environmental and management factors on guar nodulation and crop nitrogen uptake, Adams said.

Guar is grown in semi-arid regions and produces a seed containing galactomannan gum, which is a product used in a variety of food and industrial applications as a lubricant, binder, thickener or hardener, he said.

“As a legume, Rhizobium bacteria in the soil will associate with guar roots and potentially develop nodules where the bacteria converts atmospheric nitrogen into fertilizer for the plant and soil,” he said, adding that “the plant is also drought tolerant and uses relatively little water.”

Thapa said guar is unfamiliar to most people, but it is a part of their lives nonetheless.

Guar has been grown in Texas for more than a century, but acreage of the crop in the state is relatively low. (Texas A&M AgriLife photo by Dr. Curtis Adams)

“Guar gum is a common ingredient in the food we eat every day,” he said. “It is used extensively in oil and gas exploration, and in so many other ways.”

The majority of the world’s guar is grown in India and Pakistan, and the U.S. has had variable and relatively low acreage over time, Trostle said. In the U.S., guar is mostly grown across the Southern Great Plains region where the climate is suitable.

“Guar being a legume and adapted to a semi-arid region’s dryland agriculture is important,” Trostle said. “There are few legumes that would be adapted in this type of environment. That is why this work is especially important, to get potential nitrogen fixation in a legume rotational crop where it doesn’t rain a lot.”

Adams said despite the potential nitrogen benefits of the crop, there is a worldwide perception that guar does not nodulate effectively.

“So, we tested the effects of contrasting soils, a sandy loam and a clay loam, and Rhizobium inoculants on nodulation and plant growth in two guar varieties,” he said.

Although Rhizobia bacteria often occur naturally in soils, Rhizobium inoculants are crop-specific bacterial cultures prepared in the lab and applied to the seed or in-furrow at planting to increase the likelihood of root nodulation, Adams said.

He said because guar acreage is not large in the U.S., there is a lack of inoculant products specific to guar.

“In our study, we tested one commercially available inoculant and a custom inoculant prepared by a microbiologist colleague, both containing bacterial strains thought to create nodules on guar roots that fix nitrogen,” he said.

Guar has been grown in Texas for more than a century, but acreage of the crop in the state is relatively low. (Texas A&M AgriLife photo by Dr. Curtis Adams)

Thapa said two iterations of the 50-day study were run in 2017. Plant growth, plant nitrogen concentration, measures of yield potential, root nodule number, nodule weight and other parameters were determined.

“The results of this study clearly showed in different soils that guar is capable of producing plenty of nodules,” Adams said. “The soils we tested are representative of the semi-arid soils on which guar is produced around the world.

“We saw very different nodule characteristics in each soil, with a high number of nodules of low weight in the clay loam soil and low number of nodules with high weight in sandy loam. In the end, the amount of nitrogen supplied to the plants was similar between soils.”

The difference in nodule characteristics between the soils may have resulted from differences in Rhizobia population already in the soil, Adams said.

The study showed no effect of the inoculants on the number or size of nodules or plant nitrogen uptake, Thapa said.

“We are not sure why the inoculants had no effects, but it likely has to do with survival or competitiveness of the inoculant bacteria, or naturally occurring levels of Rhizobia in the soil,” he said.

“Based on the results of this study, we expect guar will nodulate and supply nitrogen in the field, as long as the conditions are right,” Adams said. “Factors like drought or low soil levels of Rhizobia bacteria could prevent nodulation.”

But little is known about the effects of external factors on guar nodulation, he said, so there are still many questions to answer.

Trostle said recent discussion with an inoculant manufacturer may provide AgriLife the opportunity to work with experimental products to expand biological nitrogen fixation in semi-arid dryland agriculture.

Trostle said four additional federally funded projects, three led by AgriLife Research, are aimed at providing more information for producers on guar in relation to guar agronomics, wheat rotation, plant breeding/adaptation and bioenergy.

And, he said, if the production builds up, Texas growers of guar seed have a market in Brownfield. The guar is processed into several different products, either for supplying specialty manufacturers who do their own refining or direct use in commercial products.

Viability of lentil, wheat rotation studied for Rolling Plains

24Jan

Writer: Kay Ledbetter, 806-677-5608, skledbetter@ag.tamu.edu
Contacts: Dr. Emi Kimura, 940-552-9941 ext. 233, emi.kimura@ag.tamu.edu

Winter lentils may be just what the doctor ordered to perk up the Rolling Plains wheat crop.

That doctor is Dr. Emi Kimura, a Texas A&M AgriLife Extension Service agronomist in Vernon.

Dr. Emi Kimura checks out early growth stages of lentils near Chillicothe at the Texas A&M AgriLife Research station. (Texas A&M AgriLife Research photo by Kay Ledbetter)

Lentils are legumes that grow in pods on a bushy plant, and as legumes, they are high in nitrogen, which would benefit the following wheat crop, Kimura said.

She has initiated a winter lentil-winter wheat crop rotation trial with funding provided by Texas Wheat Producers Board to see if this is valuable production option.

While lentil is typically planted in the spring in the Northern Plains, Kimura said concern they might not survive the Rolling Plains summer prompted her to use the fall-sown variety Morton.

Winter varieties of canola, lentil and wheat were planted on Sept. 30, 2016, in small dryland plots designed with four replications. All crops were planted using the same drill used for wheat at a rate of 60 pounds per acre on wheat, 5 pounds per acre on canola and 25 pounds per acre on lentil.

Lentils, canola and wheat growing in a field

From left to right, lentils, canola and wheat were growing in late 2016 as a part of a wheat/lentil rotation trial. (Texas A&M AgriLife photo by Dr. Emi Kimura)

Kimura said she applied insecticide March 30 as a growing aphid population was observed, especially in canola and a few in winter lentil. No fertilizer or extra water was applied to the plot.

“In our first year, we saw some positive attributes of winter lentil in the Rolling Plains, including excellent winter survival, grain production and forage potential,” she said.

Although the winter lentil was slow to fill in the rows in the fall as compared to the wheat and canola, Kimura said the lentil crop did not suffer from cold temperatures during the winter months.

The crops were harvested for grain June 6, and yields were 7.4 bushels per acre for canola, 8.3 bushels per acre for the winter lentil and 39 bushels per acre for winter wheat.

“Our winter lentil yield was lower than expected as compared to the winter lentil yield observed in the Northern Plains,” Kimura said. “We suspect the seeding rate of 25 pounds per acre used in the trial was not appropriate for our region.”

She said seeding rate is an important factor on final yield. To help determine appropriate seeding rates in the Rolling Plains, she conducted a seeding rate trial – 20, 30, 40 and 50 pounds per acre – along with the crop rotation trial during the 2016-2017 growing season.

“We found that a seeding rate at 40 pounds per acre, among the four seeding rates examined, produced the highest yield of 20 bushels per acre,” Kimura said.

This yield is similar to average U.S. lentil yields for the past 10 years, she said. The current seeding cost is $26 per acre with the 40-pounds-per-acre seeding rate.

wheat, lentil and canola seeds beside a ruler to shows how much larger lentil seeds are than the others.

Winter lentil, wheat and canola seed comparison. (Texas A&M AgriLife photo)

“We do not have a lentil market yet in Texas,” Kimura said. “However, if we continue to work on winter lentil production and accumulate enough data, I believe the market will come.”

In the past two years, lentil production has gone from about 300,000 acres nationwide to almost 1 million acres in 2016, according to the U.S. Department of Agriculture National Agricultural Statistics Service.

During harvest in 2017, the market prices for these three crops were: lentil, $510-600 per ton or $13.8-16.2 per bushel; canola, $404-475 per ton or $9.16-10.77 per bushel; and wheat, $153-160 per ton or $4.16-4.90 per bushel.

She said the lentil crop also produced a harvestable amount of crop residue after combining grain. Crop residues observed for lentil, wheat and canola were 1,154 pounds per acre, 736 pounds per acre and 0 pounds per acre of dry matter, respectively. She said canola leaves hard, woody stubble not suitable for cattle.

“We are currently processing the winter lentil forage samples for nutritive values (e.g., crude protein, neutral detergent fiber, acid detergent fiber, digestibility and relative feed quality),” Kimura said. “These values are all important parameters to influence animal performance such as intake and gain.”

The next phase of this crop rotation study was planted Oct. 12 to assess the influence of winter lentil on winter wheat production, she said. The rotations include wheat following lentil, canola following lentil, wheat behind canola, lentil behind canola, wheat after wheat, lentil after wheat and canola after wheat.

large pile of forage available after harvesting seeds

Lentil forage on June 5 following harvest. (Texas A&M AgriLife photo by Dr. Emi Kimura)

“It has been a very dry fall/winter in the Rolling Plains, and the trial desperately needs moisture, as does all wheat in the Rolling Plains,” Kimura said.

Other production information and best management practices Kimura hopes to determine during these trials include disease and insect information, variety selection, nodulation, planting dates and fertility, she said.

Inclusion of lentil in winter wheat-winter canola rotation systems increased the yield of both wheat and canola and reduced nitrogen requirements for the wheat by about 38 pounds per acre in the Northern Plains, she said.

“We are examining to see whether similar effects will occur to our wheat here in the Rolling Plains,” Kimura said.

She said a 12-year study conducted in Saskatchewan, Canada also indicated the protein contents of wheat were greater in the winter wheat-winter lentil crop rotation systems than continuous wheat production.

Another expected benefit of this rotation, Kimura said, is the nitrogen fertilizer requirement can be gradually reduced compared to the fallow-winter wheat system as a result of increased rate of net nitrogen in the root zone of wheat due to the legume.

“We believe lentil will not only add a beneficial cash crop to the rotation, but it also will greatly contribute to reducing environmental footprints,” Kimura said.

Organic grain, soybean study establishes early production recommendations

14Dec

Writer: Kay Ledbetter, 806-677-5608, skledbetter@ag.tamu.edu
Contact: Dr. Nithya Rajan, 979-845-0360, nrajan@tamu.edu
Dr. Muthu Bagavathiannan, 979-845-5375, muthu@tamu.edu
Dr. Ronnie Schnell, 979-845-2935, ronschnell@tamu.edu

COLLEGE STATION – After one year of studying organic grain and soybean cropping systems, Texas A&M AgriLife scientists say they know more about what not to do moving forward.

Organic grain sorghum under conventional tillage planted in College Station. (Texas A&M AgriLife photo by Dr. Nithya Rajan)

Three Texas A&M researchers are using a $475,000 U.S. Department of Agriculture National Institute of Food and Agriculture grant to study organic grain and soybean cropping systems over a three-year period.

The project leaders are Dr. Nithya Rajan, a Texas A&M AgriLife Research crop physiologist; Dr. Muthu Bagavathiannan, AgriLife Research weed scientist; and Dr. Ronnie Schnell, Texas A&M AgriLife Extension Service cropping systems specialist – all in the Texas A&M department of soil and crop sciences in College Station.

Year one, they said, was a learning year, as there is very little information about organic farming in Texas both for researchers and producers.

“Producers in Texas interested in organic farming have limited information on best management practices, especially for large-scale grain production,” Rajan said. “Our goal is to identify organic cropping systems and management techniques for successful production of organic grain crops in Texas.”

Rajan said they will first identify species of cover crops and planting regimens. Other goals with this study include a greater understanding of the influence of organic management practices on nutrient cycling, greenhouse gas emissions, weed population dynamics, water-yield relations and soil health.

“We knew there would be challenges meeting the nutritional needs of the crop due to restrictions on nutrient sources in organic systems,” Schnell said. “We had a plan to use legume cover crops as a nitrogen source, but we struggled to get good production from these, and that snowballed into more problems.”

He said the timing of cover crop plantings was not optimum, and some of the cover crop species selected were not adapted to the production systems in the region.

“Cereal rye is not ideal for our systems here in Texas,” Schnell said. “When it began to grow and put on biomass, it was too late to plant grain crops and the ability to mechanically terminate the crop was reduced.

“We typically plant corn near the first of March, and sorghum and soybeans in late March. The rye didn’t mature until April, which ended up being competitive with the grain crops and became more like a weed.”

Diana Zapata kneeling in field looking at plants

Diana Zapata, doctoral student, checks plant growth in rye-vetch plots. (Texas A&M AgriLife photo by Dr. Nithya Rajan)

Hairy vetch also didn’t produce a lot of biomass on a timely basis, he said.

“Weed management was a big challenge,” Bagavathiannan said. “The cover crops provided some help in this respect, but because of a lack of good biomass production, they didn’t provide enough weed suppression.

“Inter-row cultivation was very effective for corn and grain sorghum,” he said. “No-till systems were the ones suffering the most with weed pressure. Johnsongrass is our No. 1 weed problem in the plots. Because they (Johnsongrass) are perennial, inclusion of more strategic tillage in the summer and fall is important for effective management of this species.”

Schnell said the second year of their NIFA grant study will shift cover crops, including alternative cereal crops and legumes, with the same goal of supplying nitrogen and providing weed control for the spring grain crops.

“We are going to try a spring wheat instead of cereal rye,” he said. “We are fall planting it in hopes that it will be nearing maturity when we need it, late winter, so we can successfully terminate it.

“We need a dense, mature biomass from cover crops to plant into during the spring,” Schnell said. “The cover crop biomass should compete with early season weeds, but not be actively growing at that point so that it doesn’t compete with the corn, sorghum and soybeans.”

Rajan said the trio of scientists recently has also been awarded a USDA Sustainable Agriculture and Research Education grant on organic systems to specifically look at cover crops better adapted to Texas’ planting schedule.

“The other big learning experience of the first year of study is that since weed control is a problem, particularly in the no-till systems, it is important to consider some kind of minimal tillage as needed,” Bagavathiannan said.

Rajan said this study is designed to answer questions about organic practices and provide growers more information about what is normal and help them be more successful as they transition from traditional farming to organic systems.

She said there are organic feed mills that will provide good demand and a market for the crops once they are raised, so that is not the primary concern. Raising the crops successfully and understanding the best management practices are the limiting factors at this time.

“We hope with strategic management, we can bring yields up and make these crops profitable for them,” Schnell said.

He said the field research is currently ongoing on the research farm near College Station, but in the final year of the three-year project, they plan to conduct demonstrations with producers around the state.

Soil Health – Cover Crop field day held in Williamson County

23Oct

Writer: Beth Ann Luedeker

Contact: Dr. Jake Mowrer – Jake.mowrer@tamu.edu
Dr. Clark Neely – cbneely@tamu.edu
Dr. Haly Neely – hneely@tamu.edu

AgriLife Extension and the USDA Natural Resource Conservation Service recently teamed up to discuss cover crops and conservation tillage practices with producers in the Blackland region of the state. The group met at the Stiles Foundation Farm, near Thrall, and Unnasch Farms, near Hart, Texas.

Nathan Haile, NRCS, opens the Soil Health and Cover Crop field day at the Unnasch Farms. (photo by Beth Ann Luedeker)

Robert Unnasch has been practicing conservation tillage for many years. This made the field trip to his farm an excellent way to begin the day, according to the field day organizers.

“When a farmer talks, people listen,” said Nathan Haile of the NRCS. “Robert Unnasch has been doing this successfully for some time, so he has experience worth talking about.”

Haile pointed out that, according to the NRCS, there are 5 key elements for ‘soil health’ which are met by conservation tillage/cover crop practices: maintaining ground coverage; minimizing disturbances; maximizing diversity; maintaining growth year-round; and integrating livestock to redistribute nutrients.

“Cover crops should be planted as closely together as possible to aid in weed constriction, and to provide canopy to protect the soil,” said Dr. Haly Neely, Texas A&M University Soil and Crop Sciences faculty.

Dr. Haly Neely demonstrated her rainfall simulator at the workshop. (Photo by Beth Ann Luedeker)

“If you close the canopy you reduce sunlight on the ground and air across the soil, keeping the soil cooler and drastically reducing evaporation,” she said.

Minimizing disturbances means leaving the soil alone as much as possible. Under conservation tillage practices, equipment enters the field much less frequently.

“Every time you till the soil you set it back in terms of organic matter and soil bio-ecology. Not all the way to zero, but back to the minimum that soil will support,” said Dr. Jake Mowrer, Assistant professor in the Department of Soil and Crop Sciences and Texas A&M AgriLife Extension Specialist for soil nutrient and water resource management. “Any time you disrupt the continuity of the soil it takes time to recover.”

Crop diversity provides many benefits, Haile said, and can improve pest and weed management in the field.
“Having different rooting systems keep root channels open,” said Mowrer. “The plants take up different nutrients and may redistribute them to different zones in the soil where they are more accessible to the successive crops.”

But think carefully about the benefit desired from a cover crop before selecting a species, says Mowrer. For example, to add nitrogen to the soil, plant legumes; to redistribute nutrients, plant cereals; to restore soil organic matter, plant something with a high biomass, he said. In addition, a farmer must select a crop which will work well in his soil.

“Keep something growing for as much of the year as you can,” Mowrer said. “If you don’t have a living root in the system you are missing something.”
Mowrer explained that most of what is known about cover crops comes from the corn/soybean rotations in the Midwest. It is important to gain information about what works in Texas to best aid the farmers here, so AgriLife researchers have several projects underway out at the Stiles Farm Foundation.

Dr. Jake Mowrer discussed soil health at the workshop. (Photo by Beth Ann Luedeker)

One ongoing project was discussed by Dr. Clark Neely, Assistant Professor in Soil and Crop Sciences and AgriLife Extension Small Grains/Oilseeds Specialist. His research is studying the feasibility of double cropping/cover cropping and reduced tillage on wheat cropping systems. In addition to the fields at Stiles Farm, the study is replicated in Lubbock and Beeville.

“We are looking at several double cropping options including grain sorghum, sesame, and cowpea. We also have a nine-species cover crop mixture. The thought behind double cropping is to see if we can get the same soil benefits as a multi-species crop mixture and also generate some additional farm revenue at the same time,” Neely said.

Dr. Clark Neely explained his on-going conservation tillage research at the Stiles Farm. (Photo by Beth Ann Luedeker)

“The tillage component of the study compares conventional, strip-till and no-till systems,” he explained. “In addition to the soil health aspect of reduced tillage, we wanted to evaluate these double crops and cover crop mixture under each tillage system to see if strip or no-till made double cropping more feasible or reliable by conserving more soil moisture. We’ve found that strip or no-tilling double crops following wheat harvest does improve stands and ultimately yields due to greater soil moisture in the topsoil at planting.”

Based on preliminary results, sesame appears to have the best potential for generating a viable income followed by grain sorghum, Neely said. Another important finding so far is that these double crops are not having a negative impact on wheat yields, despite using more soil moisture during the summer months. The Blacklands region generally receives enough rainfall to recharge soil moisture by the time wheat is planted later in the fall.

“We are taking soil measurements on wet aggregate stability, soil infiltration rate and soil respiration, which can serve as indicators of overall soil health, but observable differences will likely take more time,” Neely said.

He and his colleagues will determine the profitability of the system through economic analysis after more years of data are collected.

Cotton, Corn and Soil discussed at 54th Annual Stiles Farm Field Day

14Jul

More than 100 producers from the Blackland region of Texas gathered at the Stiles Farm in Thrall, Texas, in mid-June for the 54th annual field day. Each year the field day highlights research being done at Stiles Farm as well as innovations in crop and livestock management.
Dr. Gaylon Morgan, Texas A&M AgriLife Extension State Cotton Specialist, discussed cotton production and new technologies for weed and nutrient management in cotton.

Dr. Gaylon Morgan presents at the Stiles Farm Field Day.

Dr. Gaylon Morgan discusses new cotton technologies at the 2017 Stiles Farm Field day.

“New herbicide technologies are not a silver bullet for weed control,” Morgan stated. “In order to get good control, producers must treat the weeds when they are four to six inches tall or smaller. Application time is critically important.”
Morgan also reminded producers to be vigilant in their application of herbicides to avoid drift to unintended areas. He stressed that Dicamba-based products have two year registration terms – after which time the products will be evaluated by the EPA and can possibly be removed from the market if too many problems have been reported.

“Keeping technologies on target will help keep those tools available to you,” Morgan said. “It also makes for better relationships with your neighbors!”

Morgan reported that, at the time of this field day, about 85% of the cotton production statewide was in fairly good condition. Dry land cotton in the high plains has taken a hit from the weather and is struggling from drught and hail events.

Dr. Jake Mowrer, AgriLife Extension Specialist in soil nutrient and water resource management, discussed fertilization rates and nitrogen stabilizer management.

“For best results with your fertilizer you want to be driving out of the field as the rains starts,” Mowrer stated, recognizing that more often than not the weather fails to cooperate.

Dr. Mowere explains importance of soil nutrient management.

Dr. Jake Mowrer explains the importance of soil nutrient management to producers at the Stiles Farm Field Day.

Mowrer told producers that Urea, a common form of nitrogen, becomes ammonium when it comes in contact with water in the soil, then undergoes another change to become nitrate. Too much water will negatively affect how much of that nitrate becomes available to the plant. Excessive rain will wash the nitrates away, or cause them to pass through the soil too quickly to be available for the plants. Ponded (standing) water prevents necessary oxygen from penetrating the soil where it will be accessible to the plants’ roots.

“If you want to manage your soil nutrients, you must first measure what is present,” Mowrer stated. “It is very important that you get a soil test.”
Dr. Ronnie Schnell, AgriLife Extension Specialist for cropping systems, explained a corn performance test he is

Dr. Ronnie Schnell explains a corn performance test he is conducting at the Stiles Farm.

conducting in which fixed ear and flex ear corn is planted at different seeding rates. Fixed ear corn varieties produce a consistent ear size regardless of plant numbers. With a flex variety, the ears will vary in size based on plant populations.
In his trial, Schnell noted that at seeding rates of 32,000 seeds per acre there was a fourteen percent drop in the number of kernels per ear in the flex varieties and a 6% drop in the fixed hybrid corn. However, there will be a balance between ear size and number of ears per acre that results in better yields.
“Try different planting rates,” Schnell suggested, “and use the planting rate which gives you the best yield for the cost of seed put into the field.”
In the sorghum trials, Schnell told producers that good yields have been realized in fields using more intensive management.
“We are only looking at a difference of $30 per acre between the high- and low-input trials,” Schnell explained. “We will see what yield differences are at harvest.”
Stiles Farm Foundation is a 2,800 acre operation in Thrall, Texas which was given to Texas A&M in memory of James E. Stiles. The farm includes 1,800 acres of crop land and a full scale commercial cattle operation.