by Nick Ashcroft,
Extension Rangeland Management Specialist
There has been increased interest in seeding rangelands lately given reoccurring drought conditions. The biggest question is, ‘Will the benefits offset the costs?’ Benefits, other than monetary might include improved management opportunities, soil stability, improved wildlife habitat, increased water infiltration, ecological services, and aesthetics. Non-monetary costs or challenges might include managing seeded areas differently (may require fencing), loss of soil (if seeding fails), or attraction of excessive wildlife numbers. In some cases, seeding may be necessary in areas where all vegetation has been removed such as pipelines or abandoned croplands. However, where there is currently vegetation, this vegetation should be considered along with the risks and costs of seeding. Seeding should only be considered when desirable plants make up less than 10-15 percent of the vegetation.
Grass seeding is a costly and uncertain endeavor on rangelands, especially in semi-arid and arid environments. Valentine (1989) identified some causal factors of rangeland seeding failures.
Germination of seed:
- Poor-quality seed (low germination, hard seed);
- Unfavorable temperature;
- Insufficient soil moisture;
- Insufficient soil oxygen;
- High soil salinity;
- Depredation by birds and rodents; &
- Insufficient soil coverage.
Emergence of seedlings:
- Seeding too deep;
- Soil crusting;
- Wind and water erosion;
- Rodent and insect damage;
- Poor-quality seed (low vigor, shriveled, damaged);
- High soil salinity; and
- Frost heaving.
- Competition from weeds;
- Competition of companion crops;
- Soil infertility;
- Insect, disease, and rodent damage;
- Lack of inoculation of legumes;
- Winter-killing and frost heaving;
- Poor soil drainage and flooding;
- High temperatures;
- Grazed too soon(i.e., before establishment); and
- Wind and water erosion (including wind shear).
Careful consideration and planning should be employed before deciding to seed rangelands, some components to consider that may improve chances of success include:
Where to seed:
- Sites with enough potential to ensure reasonable chances of success;
- Enough soil depth for adequate root development and water storage;
- Litter on the surface to reduce extreme temperatures at the soil surface;
- Areas that may receive additional moisture (i.e., runoff);
- Soil texture and the amount of infiltration, probability of surface evaporation and crusting, and amount of usable soil moisture;
- Sites with reduced competition from other plants; and
The seedbed or ability to prepare the seedbed. The ideal seedbed is very firm below the seeding depth, well pulverized and mellow on top, not cloddy nor puddled, free from live, resident plant competition, free of seed of competitive species, and has moderate amounts of mulch or plant residue on the soil surface.
What to seed:
- Grasses (cool season/warm season), forbs, and shrubs;
- Single species or multiple species;
- Native or introduced species;
- Length of individual species seed dormancy;
- Local seed. It is generally suggested that native species originate from local sources or from within 300miles south and 200 miles east, west or north;
- Plant species that are native and adapted to the ecological site (the Web Soil Survey can help in determining the ecological site and species (websoilsurvey.sc.egov.usda.gov/App/HomePage.htm);
- Seeds of known quality- germination and purity of seed;
- Establish easily; and seed price.
When to seed:
- High probability of receiving effective precipitation;
- Will depend on the physiological type of plant; cool-season grasses optimum growth temperatures 70-75oF, growth halting at around 40ºF (mid to late summer). Warm-season grasses optimum growth temperatures 85-95oF, growth halting at around 55oF (spring or early fall).
How to seed:
- Most common methods – drill or broadcast;
- Seeding depth – typically related to seed size;
- Seed contact with soil particles; and
- Mulch application to maximize benefit from precipitation.
- Management after seeding:
- Grazing; and
- Weed control.
For More information see: Range Development and Improvements, John F. Vallentine, 1989. Academic Press, San Diego California.
Seeding Native Grasses in the Arid Southwest. David R. Dreesen. USDA-NRCS Plant Materials Center, Los Lunas, NM. www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/nmpmcmt8352.pdf
Seeding New Mexico Rangeland. Chris Allison. Cooperative Extension Service Circular 525.
Horse Expo & Sale
NMSU Horse Center – Las Cruces, NM
Joby Priest, Horse Mgr. – April 16, 2016
NMSU Bull Sale
NMSU Horse Center – Las Cruces, NM
Neil Burcham – April 30, 2016
New Mexico Indian Livestock Days
Rt. 66 Casino & Hotel – May 11 -13, 2016
US Dairy Education & Training Consortium
May 16 thru June 24, 2016 – Clovis, NM
Information at email@example.com
NM Youth Ranch Management Camp
Valles Caldera, NM – June 5 – 10, 2016
NMSU Names Superintendent of Farmington Ag Science Center
New Mexico State University’s Agricultural Science Center at Farmington is entering its 50th year of existence with new leadership.
Kevin Lombard became the superintendent of the science center in November 2015 after Rick Arnold retired from the position.
“Kevin has worked with the Navajo Agricultural Products Industry, small-acreage farmers on the Navajo Nation, and the general agricultural community in the San Juan River basin since 2007,” said Steven Loring, associate director of the Agricultural Experimental Station System, as he announced Lombard’s new assignment. “We appreciate his enthusiasm for agricultural research in the Four Corners region.”
“I’m excited about the challenge of this position,” Lombard said. “I’ve been reviewing the documents that established this center in 1966 and I want to ensure that we continue to serve the agriculture community of the whole San Juan Basin.
“Agriculture has been a vital part of the San Juan Basin for centuries,” he said. “With the oil and gas boom beginning in the 1950s, agriculture has taken a back seat to the energy industry. Now the region’s economy is really vulnerable to the oil and gas industry collapsing because of lower prices.”
Because of this economic impact, Lombard wants to pursue research at the science center that can help maintain stability in the region’s economic base.
“I want us to continue to evaluate specialty horticulture crops that could help improve the agriculture community’s contribution to the area’s economics,” he said.
NMSU has had a working relationship with NAPI since the center’s beginning. Current research, including crop variety tests and weed control research, will continue at the science center.
“NAPI and the Navajo Nation are always going to be our close partners,” Lombard said of the Navajo corporation and sovereign Navajo Nation that surrounds the experimental farm. “I imagine we will continue pivot irrigation agriculture projects with them. We are unique among all the experimental farms in the statewide system, and perhaps North America, with this relationship.”
Since Lombard’s arrival in Farmington, he has conducted research in alternative crops for the San Juan River basin, including grapes, hops and medicinal herbs, and also taught horticulture classes at San Juan College in Farmington.
“I’m expecting this work to continue, including our relationship with San Juan College,” he said.
He also introduced the Garden for Health project that is helping promote home gardening in the eastern region of the Navajo Nation.
“Diabetes is a major health concern for the Navajo Nation,” Lombard said. “The Garden of Health project began because we realized Native Americans living on the reservation do not have easy access to vegetables for a healthy diet.”
During the summer of 2015, Lombard was actively involved with monitoring heavy metal contamination of the soil along the Animas and San Juan rivers caused by the Gold King Mine sludge spill at Silverton, Colorado.
“For a horticulture researcher, the spill was a once-in-a-career opportunity to study the effects of a spill that contains heavy metals,” he said. “NMSU Extension and research faculty and staff were among the first emergency responders assisting agricultural producers. The collective NMSU response made me proud to be an NMSU employee. We are committed to the
long-term monitoring of the spill’s impact.” ▫