Alan Sundermeier*, Extension Agriculture and Natural Resources Agent
Paul Houdashelt and Matt Davis, Managers, OARDC Northwest Branch Research Farm
Phil Rzewnicki, On-Farm Research Coordinator
Objective: Comparison of different wheat residue management systems for the following corn crop.
Background |
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| Site:
County: Previous Crop: Soil type: Planting Date: Harvest Date: |
OARDC NW Branch
Wood Wheat Hoytville clay 5/12/99 10/10/99 |
After wheat harvest, stubble was mowed. The experiment design was a completely randomized split plot with three replications of the whole plot treatment levels. Management systems compared were time of tillage divided into cover crop treatments: no-till, July tillage, October tillage with no cover, soybeans, and Austrian winter pea.
Tillage consisted of a pass of a chisel plow followed by a pass of a roterra power tiller to create soil conditions ready for planting. After July tillage (7/28/98), cover crops were planted on 7/30/98 with 118 lb/ac of Flyer soybeans and 127 lb/ac of winter pea. Both cover crops emerged on 8/12/98. Biomass was measured on 10/6/98 before October tillage (10/20/98) by removing above-ground cover-crop growth in one square foot and drying at 180 degrees F for 48 hours. On 6/10/99 pre-sidedress nitrate soil tests were taken. Also at that time residue counts were taken. Corn stalk population counts were done on 9/16/99. All other inputs remained constant.
| Table 1. Tillage Effects | ||||
| Tillage | Biomass gm/sq ft |
Soil Nitrate ppm |
Residue % cover |
Yield bu/ac |
| No-till | 4.5 B | 15.8 A | 92 A | 161.5 A |
| July till | 5.2 AB | 10.0 C | 64 B | 158.3 A |
| October till | 6.8 A | 11.1 B | 62 B | 158.3 A |
| Treatment means followed by the same letter are not significantly different. | ||||
| lsd (0.05) | 2.2 | 0.6 | 4.4 | 10.4 |
| cv (%) | 16.7 | <1 | 2.6 | 4.3 |
| Table 2. Cover Crop Effects | ||||
| Cover Crop | Biomass gm/sq ft |
Soil Nitrate ppm |
Residue % cover |
Yield bu/ac |
| None | ---- | 11.5 B | 69 B | 159.4 B |
| Soybean | 10.3 A | 12.1 B | 75 A | 158.7 B |
| Winter pea | 0.7 B | 13.2 A | 74 A | 161.6 A |
| Treatment means followed by the same letter are not significantly different. | ||||
| lsd (0.05) | 3.1 | 0.8 | 4.5 | 2.2 |
| cv (%) | 47.9 | 6.5 | 6.1 | 2.1 |
There were no significant interactions between tillage treatments and cover crop treatments except for soil nitrate:
| Table 3. Interaction of Tillage and Cover Crops | ||||
| Soil Nitrate (ppm) | ||||
| No Cover Crop | Soybean | Winter Pea | ||
| No-till | 15.3 | 15.7 | 16.3 | |
| July till1 | 10.7 | 9.7 | 9.7 | |
| October till2 | 8.7 | 11.0 | 13.7 | |
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1July till = Tillage before cover crops planted.
2October till = Cover crops planted no-till followed by tillage in October. |
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For the three tillage treatments, no-till had significantly more soil nitrate and residue coverage. Corn yield was not significantly different among the tillage treatments.
Soybean cover crop produced significantly more biomass before October tillage compared to winter pea. However, winter pea contributed significantly more soil nitrate as well as a significantly higher corn yield. It was observed that winter pea was able to withstand the effects of October tillage, thus allowing it to produce more soil nitrate than soybeans.
*For further information, contact:
Ohio State University Extension, Henry County
104 E. Washington St., Suite 107
Napoleon, OH 43545
419-592-0806
sundermeier.5@osu.edu