CROP YIELDS ( BU./AC.) FOR 2009 BASED ON SOIL MOISTURE AND RAIN.
2 4 4
INCHES OF WATER IN THE SOIL CROP/SOIL ZONE RAIN, MAY 1 TO JULY 31
4” 11 32
12” 30 89
This is the commentary to go with my Stubble Soil Moisture map (on page 14), which is based on soil moisture content as of November 1, 2008. Soil moisture at freeze up is the moisture that will be there in spring when the ground thaws.
Let me first thank Andy Nadler, meteorologist with Manitoba Agriculture, Ken Panchuk with Saskatchewan Agriculture, and Alberta Agriculture for its website map. I used provincial maps from these three sources to build my Prairie-wide map. Also thanks to Richard Warren of PFRA who supplied a rainfall map for August 15 to November 1, 2008 — which is the main period that can “fill” the soil profile with water, if there is enough rain. modern herbicide tolerant hybrid varieties.
Once again much of western Saskatchewan and Alberta will have to rely on timely rains during the big water use period of about June 10 to July 20.
If readers want more details on the equations used to determine crop yield potentials in the table, it is all laid out in Chapter 7 of “Henry’s Handbook of Soil and Water.” If you send a cheque for $40 to Henry Perspectives, 143 Tucker Cres, Saskatoon, Sask., S7H 3H7 we will quickly dispatch a copy of the book to your mailbox.
J. L. (Les) Henry is a former professor and extension specialist at the University of Saskatchewan. He farms near Dundurn, Sask.
Here are sample yield scenarios for three crops, based on soil moisture, soil zone and rainfall during the growing season. To see more of these, or to learn how Les Henry came up with these numbers, read Chapter 7 of his book, “Henry’s Handbook of Soil and Water.” To order it, see the last paragraph of the article.