Have a data logger set up near a fence line which has been in grass for at least for 40 years or more, and  another one in what was soybeans last year( field has been no-tilled for 20 years). There has been snow cover on both treatments since the latter part of December of last year.( I think).
 When i checked on the 29th. there was 9.5 inches snow cover near the sensors in the soybean stubble and 18 inches deep over the grass sod.
 I couldn`t push the tile probe in the soil under the soybean stubble, but could in the sod. In the sod i pushed a soil sampling probe down 20" deep and the soil was saturated to that depth. About 20 feet south of there in a grass headland i got down to 34" and soil was saturated all the way there also.
 Then a little further south in some alfalfa stubble there was frost at the ground
 surface.

 I summerized the temperatures(24 samples daily) from 1/1 to 3/28 and came up this table.


 

The 1st picture shows the soybean stubble field and 2nd  the grass sod area. Then the charts of temperatures on a few selected dates.


 

(harlans not 3 29 2013 001.jpg)

(leslies east 3 29 2013 001.jpg)

(leslies east and harlans n o t air and soil temps 1 1 2013.jpg)

(leslies east and harlans n o t air and soil temps 1 10 2013.jpg)

(leslies east and harlans n o t air and soil temps 1 11 2013.jpg)

(leslies east and harlans n o t air and soil temps 1 21 2013.jpg)

(leslies east and harlans n o t air and soil temps 2 28 2013.jpg)

(leslies east and harlans n o t air and soil temps 3 7 2013.jpg)

(leslies east and harlans n o t air and soil temps 3 15 2013.jpg)

(leslies east and harlans n o t air and soil temps 3 23 2013.jpg)

(leslies east and harlans n o t air and soil temps 3 28 2013.jpg)

harlans not 3 29 2013 001.jpg (20KB - 74 downloads)

leslies east 3 29 2013 001.jpg (34KB - 69 downloads)

leslies east and harlans n o t air and soil temps 1 1 2013.jpg (27KB - 68 downloads)

leslies east and harlans n o t air and soil temps 1 10 2013.jpg (27KB - 72 downloads)

leslies east and harlans n o t air and soil temps 1 11 2013.jpg (25KB - 72 downloads)

leslies east and harlans n o t air and soil temps 1 21 2013.jpg (26KB - 70 downloads)

leslies east and harlans n o t air and soil temps 2 28 2013.jpg (26KB - 73 downloads)

leslies east and harlans n o t air and soil temps 3 7 2013.jpg (25KB - 79 downloads)

leslies east and harlans n o t air and soil temps 3 15 2013.jpg (26KB - 79 downloads)

leslies east and harlans n o t air and soil temps 3 23 2013.jpg (25KB - 73 downloads)

leslies east and harlans n o t air and soil temps 3 28 2013.jpg (25KB - 76 downloads)