Dennis Baker, Extension Agriculture and Natural Resources Agent
The objective of this research is to determine if the use of inoculate on soybean seed will improve the yield of soybeans when planted after corn in a corn-soybean-wheat rotation.
| Test Site: | County Farm | Herbicide: | |
| County: | Darke | PRE | 26 oz/A Roundup Ultra Max |
| Nearest Town: | Greenville | 1.4 oz/A | |
| Soil Type: | Miami silt loam and Eldean loam | POST (July 10) | 26 oz/A Roundup Ultra Max |
| Drainage: | Subsurface | Variety: | Croplan 3276 |
| Tillage: | No-till | Planting Rate: | 187,000 seeds/A |
| Previous Crop: | Corn | Planting Date: | April 30, 2001 |
| Soil Test: | pH 6.9, P 35ppm, K 160ppm | Row Spacing: | 30 inch |
| Fertilizer: | 0-40-0 (100 lb/A) and 0-0-46 | Harvest Date: | October 3, 2001 |
| (125 lb/A) broadcast |
Two treatments consisting of planting the soybeans with inoculate and planting without inoculate were replicated six times in a completely randomized block design. Inoculate used was the recommended rate of the powdered form of USDA Inoculate. Inoculate was kept cool until used. Seed without inoculate was planted before inoculated seed was added to the planter. Each individual treatment strip consisted of twelve 30-inch rows and was approximately 4/10 acre in size. The seeds were planted using a Buffalo slot planter with Kinze brush-type seed meter units. Soil conditions were very good at planting. There was adequate rainfall to germinate seed uniformly. Entire strips were harvested for yield results. Harvest moisture was determined using a field moisture tester. A weigh wagon was used to determine weight of grain harvested in each plot. Yields were adjusted to 13% moisture.
| Table 1. Soybean Yields. | |
| Treatment | Yield |
| (bu/A) | |
| Inoculated Soybean Seed | 62.3 |
| No Inoculate | 61.9 |
| F | < 1 |
| LSD (0.05) | NS |
| CV (%) | 2.3 |
There were no significant differences when comparing yields of soybeans treated with USDA inoculate to non-treated seed. Much research shows that the use of inoculate on soybean seed improves yield significantly, even when soybeans are included in a rotation. Results in this trial did not substantiate that because of an already high yield environment, good crop rotation that includes soybeans, or poor inoculate. Soybeans were planted into relatively dry soil, but soil moisture conditions improved to adequate within the next week. Above-normal temperatures allowed the seed to germinate and start growing quickly. Moderate temperatures and adequate growing conditions throughout the growing season allowed for optimum conditions for soybean nodulation to occur.
For further information, contact:
Dennis Baker Ohio State University Extension, Darke County 700 Wayne St. Greenville, OH 45331 937-548-5215 baker.5@osu.edu