Interseeded Cover Crop Species Effect on Establishment, Weed Control and Yield

Using a drill InterSeeder developed by Penn State to interseed cover crops between the rows of growing cash crops is a novel method to increase the amount of time cover crops can grow before winter. The InterSeeder offers enhanced cover crop establishment, the ability to interseed into no-till planted cash crops, and decreased labor and fuel requirements.

Drill Interseeding Effects on Establishment, Weed Control, and Yield
This project was part of a larger InterSeeder project replicated in PA and MD. The goals of this work were to evaluate the benefits of cover crop interseeding across a range of soil and environmental conditions, to measure how interseeded cover crops influence cash crops, and compare different cover crop varieties for interseeding. On-farm work was a substantial part of our research (see case studies). Our work began in summer 2013 where treatments of cover crops were interseeded into corn and soybeans in participating farmer’s fields and at our own Musgrave research farm.

In 2014 we measured soil Nitrogen from the previous year’s cover crops, with the goal of producing Nitrogen fertilizer recommendations using the Adapt-N model. The following year we applied two Nitrogen fertilizer rates (Standard and Low) using the Adapt-N model.

Another aspect of the project was testing the performance of 14 different cover crop varieties planted into soybeans. We were interested in which cover crop varieties were the most promising for interseeding. A similar study examined 11 different types of annual ryegrass. Finally, a herbicide study explored how interseeded cover crops reacted to 17 different pre-emergent herbicides.

Methods
Corn was planted using typical methods and we interseeded cover crops into the corn at the V4-V6 growth stage (before the collar of the 12th leaf is visible). We rated cover crop stand establishment, quantified corn yield, measured biomass production of the cover crop, and sampled soil.

Results
Below, view a poster and a presentation on the results from this work.

interseeding poster
Poster: effects of cover crop interseeding on establishment, weed control, and crop yield.