Range forage production on the Corona Range and Livestock Research Center (CRLRC) is tied closely to climate and weather conditions, especially seasonal rainfall amounts.
Recorded data include hourly measurements of precipitation, air tem-perature, soil temperature at 10 cm (4 inches) and 50 cm (20 inches), relative humidity, wind speed and direc-tion, and soil moisture at 10 cm (4 inches) and between 10 cm and 30 cm (4?12 inches). Approximately 88% of the elapsed hours over the July 1990 through 2007 period recorded a reading
Soil volumetric water content (volume of water per volume of soil)
The Natural Resources Conservation Service (NRCS) maintains a Soil Climate Analysis Network (SCAN) site on the Corona Ranch
Long-term average rainfall for the Corona, New Mexico, area recorded between 1914 and 2006 was 14.6 inches with a standard deviation of 4.7 inches , minimum annual rainfall over the 1914?2007 period occurred in 1917 (5.81 inches) and the maximum oc-curred in 1941 (36 inches)
Figure 2. Historical Corona area seasonal and annual rainfall amounts [pdf 3]
New Mexico is influenced by the North American monsoon and gets 40 to 50% of annual rainfall during the monsoon season (late June through early October)
At the 10 cm (4 inch) depth, the OW data logger consistently recorded about 20% higher than the SH data logger. At the 10?30 cm depth, soil moisture recorded at the SH site was about 6% higher than at the OW site. [about 3km apart on ranch]
Figure 5a. Soil moisture measured at 10 cm (line) and daily rainfall (bars, in mm), SH site, 2002?2003. [pdf 13][shows spikes in soil moisture with rain, no retention]
at least 5 mm (0.2 inches) of rainfall to substantially increase soil moisture levels over the day. When it did not rain on a given day, soil moisture decreased on aver-age by 0.2%. For the dry climate of the Corona Ranch, soil moisture is largely built rainfall events > 5 mm, by which were recorded on about 20 days of the year
Both soil moisture probe depths placed at the OW and SH sites recorded a similar pattern, but the deeper probe (data not shown) remained at a slightly higher level.
Over the 2001?2006 period during quarters 1 and 4, the 10?30 cm probe recorded soil moisture levels that averaged 3.5% more than the 10 cm probe. The differ-ence increased to 7.6% during quarter 2 and 5.6% during quarter 3
Average daily maximum air temperature at the OW and SH study sites was 50°F during December?January and 84°F in July. Average daily minimum air temperature was 25°F during December?January and 57°F in July.
The average frost-free period (consecutive days above 32°F) was about 164 days, from April 30 to October 11
Perhaps more important for range forage production, an approximate 50°F is considered a mini-mum temperature for growth of blue grama grass (Stub-bendieck & Burzlaff, 1970) [this happens early april to late oct, daytime temps stay over 50F]
Figure 7. Daily average minimum and maximum air temperature and average diurnal air temperature recorded at the OW and SH study sites (July 17, 1990?July 3, 2007).
Figure 8b. Daily average minimum and maximum soil temperature (10 cm and 50 cm) measured at the SH and OW sites (July 17, 1990?July 3, 2007). [pdf 16]
Figure 10. Percentage of hours with different maximum and average wind speeds, and the hourly average wind direction (July 17, 1990?July 3, 2007). [pdf 18]
average wind direction (in degrees) over the day. As shown, wind has a southerly component 90% of the time, and it blows nearly every day.
At 50 cm (20 inches) the daily range in soil temperature was only about 1°C, as compared to 9°C for the 10-cm (4-inch) probe.
Average relative humidity was 25% with monthly averages ranging from 19% during June to 30% during January. Average relative humidity varied from about 30% in the early morning and evening hours to less than 20% by mid-day.