Forage Aridity Index from Agroecological Resource Areas (ARA) Database
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:
|SAND, SANDY LOAM||100|
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.
 Weighted mean for day n= (Tn-2 + 4Tn-1 + 4Tn + Tn+2) / 16
|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  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|
- Date Modified: