Monday, June 18, 2012
Time For Root Digs
"Root growth is a gravitropic response, i.e., roots naturally develop downward in response to gravity as long as conditions are conducive for continued development. Conducive conditions are primarily adequate moisture and temperature but also obviously include soil tilth. Generally, wet soils early in the season result in shallower rooting primarily because wet soils warm more slowly. If upper soil layers warm slowly, deeper soil layers warm even more slowly (less heat conductance). If deeper soil temperatures are limiting (i.e., less than 50 degrees F), roots will tend to proliferate in the warmer, upper soil layers. Conversely, drier than normal periods following corn planting tend to encourage deeper rooting because the deeper soil layers warm more quickly. Roots do not grow toward water. They proliferate where conditions are conducive."
It's time for root digs in corn to see how we are doing. I have been digging plants since emergence but now is a good time to see what is going on under the surface soil.
Conditions were not conducive for root growth in April so we have just about every root problem symptom in someone's corn field this year. I hope it is not yours! It sure is in mine so if you want to see some unusual condtions, come on over!
These problems have resulted in fields with very uneven plant heighth and growth. Farmers have been sharing pictures of fields on Crop Talk with newly emerged or stunted plants beside plants ten times its size. I have some of those.
Many farmers and most agronomists, scouts or consultants carry a spade in their pickup for root digs. If you got some rain like we did, you dig as far as you can and gently lift up, saving all the root hairs you can. Some dig easy, some dig hard. Some break off, others stay intact. Some conditions on some days dig eaier than others.
Look for actively growing, healthy roots. I have found yellow, brown and black spots on root crows and those are signs of sick plants. They may not make an ear. Find out how and why you got them. There are many causes.
It is also a good time to pull tissue, one large leaf per acre for lab analysis. Nutrient imbalance and micronutrient deficiency are easily discovered this way. You may want to pull a soil sample at the area of the pulled plant tissue if you want more thorough information.
It's time to do root digs, so get digging!