I found a chart in the following link http://precisiontillage.com/archive/assets/uploads/Root%20growth_temp_important2007.pdf  that compares the growth rate of roots at different soil temperatures. So i had to check it out on soil temperatures i collected, one in bare soil and the other in soybean residue covered soil. The temperatures were recorded every 15 minutes. I then averaged the temperatures on a daily basis. The following table shows what i came up with.

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(root growth.bmp)

(home place sm n o s vs antelope se half circle average daily 2 inch soil temps root growth starting 6 12 2015.bmp)

(home place sm n o s 1 collar 6 21 2015.jpg)

(antelope se half circle 5 collar 6 21 2015 2.jpg)

root growth.bmp (548KB - 196 downloads)

home place sm n o s vs antelope se half circle average daily 2 inch soil temps root growth starting 6 12 2015.bmp (584KB - 182 downloads)

home place sm n o s 1 collar 6 21 2015.jpg (305KB - 188 downloads)

antelope se half circle 5 collar 6 21 2015 2.jpg (223KB - 184 downloads)