What caused bare spots in the left-center part of the field?
Hint: This 5% grade field slopes to the right (North). This picture was taken July 2, 2013.
Very heavy spring rains caused the problems you see. This well-tiled, sandy soil field received 21.67 inches of rain between April 1 and July 2, 2013. It received 2.09 inches on May 19, 2.17 inches on May 26, and 2.17 inches on May 29, 2013.
Historically, this field does not produce much up in the left-central part due to a sandy ridge that runs there. Erosion channels run horizontally, from left to right into a big buffer to the North.
What caused the diagonal green lines in this photo?
Hint: The corn rows are parallel to the road.
The angled lines are tile drainage.
The squiggly lines result from uneven nutrient application.
The bare strip by the road is from an empty planter.
What caused the horizontal tracks across the center of the field? What caused the dark lines (differences in crop height)?
Hint: The field rows are parallel to the road at top of photo (left to right).
Because it was photographed early (6:50 am on July 29), the dark diagonal lines are shadows of taller corn plants shading shorter corn plants, so the lines reveal crop-height differences. These dark lines are at an angle to the crop rows.
The horizontal tracks across the field result from compaction created on wet days when manure was applied. But this is not just a compaction problem. The differences in plant height (dark diagonal lines/shadows) result from uneven manure spreading.
This farmer was advised to:
- Wait for dry soils before applying manure
- Align the manure application knives with planting traffic, to reduce the area compacted (not done in the photo). Plant corn in the same alignment as applicator went
- While it may be difficult to do this if you use a busy contractor, these mistakes probably cost 30-40 bushels of yield, Recker estimates.
What happened to cause the uneven row patterns?
In addition to the planter skips in the lower right corner, there are numerous other bare spots caused by human error. What happened?
The sidedress-rig driver deviated from the row and ran down a lot of corn.
What caused the bare spot in the center of the photo?
Hint: The water in this field flows from bottom to top.
The terrace did its job, but eventually the water overflowed on the right side, creating a new erosion path.
The bare spot is from ponding caused by the terrace concentrating water in a wet year.