Jacob Bolson - 3/23/2009 13:16
Singles. Why?
The forces from a tire are not straight down; they arc out downward from the tire. If you are planting with duals, you are compacting both sides of the root zone of the plants between your tires. If you are planting with singles, you are compacting only one side of the root zone. Plants can handle compaction on one half of the root zone, they can not handle compaction on both sides. This compaction problem becomes worse with higher levels of tillage because of the decreased soil structure. In a conventional tillage field, I am very confident to say that if you plant with duals, a row-by-row yield analysis would show a statistically relevant yield drag on the row that was planted between your duals. It does not matter what kind of bells and whistles you add to your planter row unit, compaction is compaction.
The idea of planting with singles is why you see folks in a consolidated controlled traffic farming system planting with singles. I have had an opportunity to spend a lot of time studying row-by-row yield analysis with Robert Recker
(
http://www.agweb.com/FarmJournal/Article.aspx?id=146677 ) and one thing that his research has taught me is that if you run a statistical analysis on data from a multi-year controlled traffic field, it is very difficult to locate a yield drag due to the traffic lanes.