Forage Aridity Index from Agroecological Resource Areas (ARA) Database

FORARID.DAT

This file contains the Forage Aridity Index (Shields and Sly, 1984) for four soil water holding capacities. It also contains the start and end of the growing season, and the Accumulated Growing Degree-days (AGDD) > 5 degrees C to selected dates. The file contains data for each year for the 1965- 1985 period. The soil textures and corresponding Available Water Holding Capacity (AWHC) are as follows:

Texture AWHC (mm)
SAND, SANDY LOAM 100
LOAM 150
CLAY LOAM 200
CLAY 250

If the soil is Solonized Solonetz or Organic, then the AWHC is not applicable. For the aridity index, water holding capacity of the soil = field capacity − permanent wilting point.

Reference: De Jong et al. (1991a).

One record per ARA per year.

Item Name Description Reporting Units

N.B. All AGDD are reported to the nearest whole number.

[1] Weighted mean for day n= (Tn-2 + 4Tn-1 + 4Tn + Tn+2) / 16
Where T is mean daily air temperature

ARANO ARA Number  
PROV Province  
YEAR Year  
ARID1 Aridity Index (AWHC 100 mm) mm
ARID2 Aridity Index (AWHC 150 mm) mm
ARID3 Aridity Index (AWHC 200 mm) mm
ARID4 Aridity Index (AWHC 250 mm) mm
GROWS Start of Growing Season
-Day when 5 day weighted [1] mean air temperature > 5.5 degrees C and stays above
Julian day #
GROWE End of Growing Season
-Day when 5 day weighted* mean air temperature goes below 5.5 degrees C
Julian day #
MAY1 AGDD from GROWS to May 10  
MAY15 AGDD from GROWS to May 15  
JUN1 AGDD from GROWS to June 1  
JUN15 AGDD from GROWS to June 15  
AUG1 AGDD from GROWS to August 1  
AUG15 AGDD from GROWS to August 15  
SEP1 AGDD from GROWS to September 1  
SEP15 AGDD from GROWS to September 15  
OCT1 AGDD from GROWS to October 1  
OCT15 AGDD from GROWS to October 15  
NOV1 AGDD from GROWS to November 1  
GROWSTTL AGDD from GROWS to GROWE