If you're looking for another reason to re-check your tire inflation one last time before you hit the acres, you may have just found it.
The Northern New York Agricultural Development Program — with help by a researcher from the Cornell University Cooperative Extension — issued an academic report this week on a link between compaction and yield.
While plant development impacts come as second-nature to most no-tillers, or even conventional tillers who watch the headlands carefully, researchers sought to quantify yield vs. compaction.
"While it is generally understood that severely compacted soils limit plant root development and reduce soil function, especially in a wet season, it is not known whether this wide variation in compaction severity is directly proportional to, or a driver of, crop yield performance within a field," they wrote.
A prior study examined only headlands, the region of the field expected to be low yielding because of overlapping field passes, and found that 90% of all headlands were compacted, and the average yield loss for headlands was about 15%.
Researchers collected 360 soil penetration measurements using a penetrometer on 2 fields each on 2 New York dairies, where corn was being grown for silage.
The readings were taken in areas using a previously devised system to divide regions of fields based on yield. Researchers focused on regions labeled Q1, where yields are consistently above average, Q3, where yields are inconsistently below average, and Q4, where yields are consistently below average. A fourth category, Q2, or regions where yields are inconsistently above average, was not sampled for the report.
Researchers found low compaction areas corresponded to high-yield areas.
"It is likely that the causes of yield reduction for Q3 and Q4 zones, in comparison to Q1 zones, may be numerous and variable across fields or years, but one potential cause may be increased soil compaction as revealed in this study," they wrote. "This data will be further analyzed, in conjunction with other data from these same fields, to provide more understanding of this relationship between soil compaction, and soil health, with yield stability across years."
Compaction is more severe on conventionally tilled farms, the researchers observed.