Simultaneous Interseeding of Corn and Cover Crops at Various Row Spacings

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2020: $18,000.00
Projected End Date: 12/31/2022
Grant Recipient: Bowman Farm
Region: North Central
State: Illinois
Project Coordinator:
Andrew Bowman
Bowman Farm


  • Agronomic: corn


  • Crop Production: cover crops, intercropping

    Proposal summary:

    Incorporating cover crops into row crop systems has been shown conclusively to be an economically viable, ecologically sound, and effective soil conservation and weed suppression method, both at a research and farm-scale level.

    However, widespread interseeding of cover crops into a standing primary crop for general weed control and soil conservation purposes has been hindered because typical practice post-emergence interseeding requires multiple passes with specialized or highly modified equipment. Resulting cover crop performance is often mixed, with poor emergence, irregular establishment, and poor early competition with weeds especially in organic systems. Without seeing consistent results, farmers will be slow to adopt interseeding cover crops.

    This project proposes:

    • to simultaneously plant a corn with a mixture of shade-tolerant cover
    • To modify a no-till drill (for the cover-crops) by adding precision planting units (for the row-crop specialty corn), likely a modified Monosem twin-row, single-row or comparable precision planting unit;
    • To compare cover crop and crop yield response to four corn planting widths: 5 inches (single row) 15 inches (single row), 30 inches (single row) and 60 inches (twin-row).

    Success would yield economic gains, reduced pesticide load, and increased soil biodiversity while reducing workload for farmers.

    Project objectives from proposal:

    1. To successfully establish a simultaneously interseeded specialty corn/mixed cover crop;
    2. To modify a no-tillage drill into an interseeder for both cover crop and row-crop planting in organic no-till and strip-till systems;
    3. To compare the effects on corn yield and cover crop emergence and growth (height and biomass) of a high-density narrow row corn spacing (8.5 inches and 15 inches) versus standard (30 inch) and wide row spacing (60 inch twins);
    4. To showcase the results to passersby as well as clients of our partner cooperator thru signage, photographs, videos, data collection, press releases and field days ;
    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.