The theoretical advantages of ultra narrow corn rows are that plant spacing is more equidistant, the crop canopy closes faster, and weed control from a crop competition standpoint is improved (this one is questionable). Some disadvantages include the current lack of narrow row equipment, the cost of converting or replacing current equipment, and the challenge of doing field operations after the corn has emerged.
the past 5 to 8 years, silage research has been performed in several
northern states. In New York,
a 5 percent yield advantage was seen with 15 versus 30-inch rows in a
multi-year trial. Penn State
University researchers documented a 10 percent silage yield increase with
narrow rows compared to conventional row spacings.
In 1997 through 1999, a Michigan State silage study compared 15,
22, and 30-inch row spacings using four different hybrids.
Silage yields were increased by 8.2 percent with 15-inch rows and
4.7 percent with 22 inch rows compared to 30 inch row spacings.
1997-99 Wisconsin Results
row corn silage research results from five locations around Wisconsin are
presented in Table 1. At each
location, corn was planted in 30-inch rows and either 15 or 20-inch rows.
All trials represent data from replicated field plots.
Results from the Wisconsin studies seem consistent with those documented in other states. Response to growing corn in narrow rows has ranged in yield response from -1.1% to +24.9%. There are likely some hybrid differences in terms of response to narrow row spacings, however, not enough information is known to date for making specific recommendations. It would appear that at least some positive corn silage yield response might be expected from growing corn in narrow rows.
When sifting through the narrow row information, costs must be weighed against potential yield benefits. For some, modifying existing corn planters may be done without a large capital outlay. For others, it may mean purchasing new equipment at a much higher cost. This is clearly a management practice where the return will be more easily justified when larger acreages are planted. Each farm situation will be different.
cost of converting to narrow row corn production may be less of a factor
with corn silage compared to grain when we consider the fact that several
custom operators have choppers with the row-insensitive Kemper heads.
With more producers now utilizing custom operators to do their
harvesting, the ability to get the crop harvested without an increased
cost may make narrow rows more appealing.
Additionally, at least two custom operators in the area are now
offering narrow row corn planting services.
Plant Density Effects
In each Wisconsin narrow row corn silage trial, plant density effects were evaluated. There was little or no benefit to increasing final plant populations beyond 35,000 plants per acre with narrow row production. Results from other states are similar.
For more information contact Mike Rankin