Last year we no-till planted corn into rye stubble. We had the row cleaners locked up. I put temperature sensors two inches deep , one in the seed slot and one midway between two rows. The temperature in the seed slot was running warmer than in the middle of the two rows. This year i set up the same test to see if i could repicate the results from last year. To my surprise i didn't get the same results, i had two different fields that i set up a test in this year, they both showed the same results, in that the seed slot temperature was nearly the same as the temperature between the two rows. The only major difference is last year we planted the corn with our own planter that has the spiked closing wheels and this year we had our corn custom planted, both planters had smooth closing wheels. There could be other reasons but this is what comes to mind.