Eighteen Years 90-07 Climatological Data NMSU Notes

• 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.