Physiographic features

This site occurs on nearly level to moderately sloping narrow ridge tops or on the convex portion of the landscape at elevations from about 3,800 to 5,900 feet above sea level. Slopes are generally 0 to 9 percent but may range to 15 percent.

Table 2. Representative physiographic features

Climatic features

The climate of this area can be classified as “semi-arid continental”.

Precipitation averages from about 15 to 16 inches annually with approximately 75 percent of this yearly moisture falling during the period of May through October. Most summer rainfall is associated with usually brief afternoon and evening thundershowers, which occasionally produce heavy rain over a small area, and sometimes bring a little hail. Winters are generally dry, with only one or two days a month when as much as one-tenth inch of moisture falls. However, winter average 20 inches of snow, although most snowfalls are light with an occasional storm producing up to six inches. Following these storms, snow may lie on the ground for several days and occasionally moderate to strong winds accompanying these storms result in blizzard conditions and heavy drifting. Although the precipitation patterns favor the production of warm-season plants, sufficient moisture is received in the late winter and the spring to support cool-season plants. Approximately 25 percent of the annual precipitation is received during April and May. May is generally the wettest month followed by July and then August.

Temperatures show the seasonal changes and large annual and diurnal ranges characteristic of such a climate. Summers are generally mild. The high daily temperature reading exceed 90 degrees F about one-third of the time, and readings of 100 degrees F occur about once a year. Rapid cooling after sundown results in minimum temperatures below 60 degrees F on most nights, even in midsummer. Winter shade temperatures usually rise to the mid-40’s and an average of only 15 days fail to see temperatures rise above the freezing mark most of the time from early November through March; below zero readings occur on an average of only three times a year.

The freeze-free season ranges from 168 days to 171 days between April 28th to October 16th. Both temperatures and annual precipitation favor warm-season plants. About 40 percent of the annual precipitation is received during the season where temperatures will benefit cool-season plants and only 10 percent falls during the dormant season.

While open to winter invasions of arctic air over the Great Plains, this area is far enough south and west to miss many of these outbreaks. Mountains to the north and west intercept mush of the precipitation from the Pacific northwest storms coming through this area during the winter. An average hourly wind velocity for the year is 15 miles per hour. Somewhat higher winds prevail during the spring months, but velocities exceeding 24 mile per hour are experienced only 10 percent of the usual year. Stronger winds blow chiefly from a westerly or southwesterly direction during the spring. Relative humidity is moderately low.

Climate data was obtained from http://www.wrcc.sage.dri.edu/summary/climsmnm.html web site using 50% probability for freeze-free and frost-free seasons using 28.5 degrees F and 32.5 degrees F respectively.

Table 3. Representative climatic features

Climate stations used

• (1) CLAYTON 1 N [USC00291883], Clayton, NM

• (2) DALHART 6 SW [USC00412235], Hartley, TX

• (3) AMISTAD 5 SSW [USC00290377], Amistad, NM

• (4) ROSEBUD 7NW [USC00297585], Mosquero, NM

• (5) MCCARTY RCH [USC00295516], Nara Visa, NM

Influencing water features

This site is not influenced by water from a wetland or stream.

Wetland description

None.

Soil features

The significant soils that characterized this site are loams, fine sandy loams and clay loams that average less than 20 inches in depth and more than five inches in depth. The underlying materials are indurated caliche. Permeability of these soils is slow to moderate. The available water-holding capacity is low. Effective rooting depth is from 6 to 20 inches. The plant-soil-moisture-air relationship enables plants to respond to light rainfalls.

Soils correlated to this site: Plack loam

Table 4. Representative soil features

Animal community

No Data.

Hydrological functions

The runoff curve numbers are determined by field investigations using hydrologic cover conditions and hydrologic soil groups.

Hydrologic Interpretations
Soil Series----------Hydrologic Group
Dean-----------------C
Pastura--------------D
Plack----------------D

Recreational uses

This site has limited recreation potential, limited mainly by the lack of live water and shade. Hunting for small game and antelope is good. Photography of small animals, birds, antelope and flowering plants is fair to good. The natural beauty of the site is enhanced by the large variety of flowering plants that bloom from spring to fall.

Wood products

This site has no significant potential for wood products.

Other products

Grazing:
This site can be grazed any season of the year by all kinds of livestock, generally without regard to age. A portion of the total stocking rate favors sheep and antelope due to the site’s potential to produce forbs. The large variety of plants provides good nutrition during most seasons of the year. Supplemental protein is needed only during late winter. Emergency feed is required during heavy snow cover; however, this site is among the first that snow will melt off. This site is among the first to green up in the spring and will usually respond to light amounts of rainfall. Continuous yearlong grazing or grazing continually by cattle during the period from April through October will cause the site to deteriorate and become less productive. Species such as sideoats grama, little bluestem, New Mexico feathergrass, needleandthread and winterfat will decrease and blue grama, threeawn spp., wolftail, tridens, broom snakeweed and forbs will increase. A system of deferred grazing, which varies the season of grazing and rest in each pasture during successive years, is needed to maintain or improve the plant community. Different seasons of rest and grazing benefit different plants. Spring rest (April-June) will allow cool-season forbs and grasses such as New Mexico feathergrass and needleandthread to grow and reproduce. Summer rest will benefit warm-season grasses such as sideoats grama, little bluestem, and blue grama. Fall rest allows plants to complete their growth cycle. Winter rest will benefit the woody species such as winterfat and sagebrush. Grazing is beneficial after the seed sets and aids in trampling in the seed.
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Other information

Guide to Suggested Initial Stocking Rate Acres per Animal Unit Month

Similarity Index----------Ac/AUM
100 - 76------------------2.6 – 4.4
75 – 51-------------------3.2 – 6.8
50 – 26-------------------4.4 – 12.0
25 – 0--------------------12.0+

Type locality

Other references

Data collection for this site was done in conjunction with the progressive soil surveys within the Southern High Plains 77 Major Land Resource Area of New Mexico. This site has been mapped and correlated with soils in the following soil surveys: Union, Harding Colfax.

Characteristic Soils Are:
Plack

Other Soils included are:
Dean----------Pastura

Contributors

Don Sylvester
Elizabeth Wright
Wendy McCoy
Todd Carr

Approval

Bryan Christensen, 9/11/2023