Mike Rankin
Crops and Soils Agent - Fond du Lac County
University of Wisconsin - Extension
Background
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. 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.
During the past several 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, a Michigan State silage study compared 15, 22, and 30 inch row spacings using four different hybrids. Silage yields were increased by 12.8 percent with 15 inch rows and 10.2 percent with 22 inch rows compared to 30 inch row spacings. Hybrid differences ranged from a +6.3 percent yield increase to a +17.7 percent increase.
1997-98 Wisconsin Results
Narrow row corn silage research results from several 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.
| Table 1. Wisconsin Narrow Row Corn Silage Studies in 1997-98 | ||||
| Location | Year |
Row Spacing |
Yield Response |
|
30 |
15/20 |
|||
---tons/acre @ 65% moisture-- |
% |
|||
| Arlington | 1997 1998 |
14.0 30.3 |
14.6 30.0 |
+4.3 -1.0 |
| Sheboygan | 1997 1998 |
22.0 25.7 |
24.6 27.0 |
+11.7 +5.0 |
| Fond du Lac | 1998 |
26.9 |
30.3 |
+12.6 |
| Monroe Co. | 1997 1998 |
21.4 22.5 |
24.9 28.1 |
+16.0 +24.9 |
| Valders | 1998 |
23.7 |
24.9 |
+5 |
| Mean | 23.3 |
25.6 |
+9.9 |
|
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 -1.0% 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 where larger acreages are planted. Each farm situation will be different.
The 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 these custom operators, the ability to get the crop harvested without an increased cost may make narrow rows more appealing. Additionally, one custom operator is now offering corn planting with a narrow row machine.
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. Average yield results in 1997-98 for the Sheboygan County silage study are presented in Figure 1.
Figure 1
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more information contact Mike Rankin