Cereal rye (CR), the most common and effective nitrogen (N) scavenging
cover crop option in the Midwest, is often utilized in cropping systems to
reduce nitrate loss for environmental benefits. To increase environmental
efficiency in Midwest corn cropping systems, we must increase the overall
adoption of CR. However, due to the yield reduction potential (6%) for corn
planted after CR termination, CR is primarily recommended before soybean. To
increase CR adoption, we must develop adaptive fertilizer management practices
that achieve competitive grain yields relative to cropping systems where CR is
not adopted. Therefore, the objectives of this study are to determine (1) the
effect of CR and starter nitrogen rate on corn growth and nitrogen content. (2)
the optimum starter nitrogen rate to achieve agronomic optimum corn yield
following CR. (3) the impact of phosphorus (P) at starter on plant growth,
nitrogen content, and yield with the inclusion of CR. For our study, five
starter N rates were applied in a 5x5 cm band to both CR and non-CR plots,
concentrations ranged from 0-84 kg N ha<sup>-1 </sup>in 28 kg N ha<sup>-1</sup>
intervals. Total N applied was the same for each treatment, relative to its
location, and was split between starter N at planting and sidedress applied at
growth stage V6 relatively. Although CR termination took place at least two
weeks before planting, CR decreased corn grain yield at one of three locations
by an average of 8%, nitrogen recovery efficiency (NRE) by 27%, and R6 total N content
by 23%, relative to the conventional control (non-CR 0N), when no starter N was
applied. At one of three locations, starter N rates of 56 kg N ha<sup>-1</sup>,
56 kg N ha<sup>-1 </sup>plus 17 kg P ha<sup>-1</sup>, and 84 kg N ha<sup>-1</sup>
increased corn grain yield, in CR plots, and 56 kg N ha<sup>-1</sup> plus 17 kg
P ha<sup>-1</sup> increased corn grain yield in non-CR plots. Phosphorus increased
corn grain N content at growth stage R6 in one of three locations and did not
impact corn grain yield at all locations. We conclude that the inclusion of
starter N at planting has the potential to increase agronomic productivity in
CR corn cropping systems in soil environments with a high capacity to
mineralize soil N. However, further research is required to refine our starter
N results to find an optimum starter N rate to apply before planting corn
following CR.
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/10265462 |
| Date | 20 November 2019 |
| Creators | Houston L Miller (7830965) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/INVESTIGATION_OF_CORN_YIELD_IMPROVEMENT_FOLLOWING_CEREAL_RYE_USING_STARTER_NITROGEN_FERTILIZER/10265462 |
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