Using Drones to Measure Cover Crop Biomass as a Predictor of Soil Nitrogen And Corn Emergence Issues

Project Overview

Project Type: Graduate Student
Funds awarded in 2020: $14,832.00
Projected End Date: 07/31/2021
Grant Recipient: University of Delaware
Region: Northeast
State: Delaware
Graduate Student:
Faculty Advisor:
Dr. Jarrod Miller
University of Delaware

Information Products


  • Agronomic: corn


  • Crop Production: application rate management, cover crops, nutrient management, seed saving
  • Education and Training: decision support system, extension
  • Soil Management: soil quality/health

    Proposal abstract:

    Cover crops are a common soil health management practice adopted by Delaware farmers who seek to capitalize on ecosystem services like N fixation, nutrient scavenging, and soil cover. Cover crop termination timing can play a huge role in the level of ecosystem services provided to the following cash crop. Later terminated cover crops are able to establish more above and below ground biomass and, in return, can produce additional root systems that encourage microbial diversity or, in the case of legumes, fix more N. However, later terminated cover crops can inhibit seedling germination by reducing seed to soil contact at planting. We will investigate different seeding rates of cover crop mixes to identify the seeding rate that provides the most opportunity for ecosystem services from cover crops yet does not inhibit germination of the subsequent cash crop. We will use drone imagery to observe and compare cover crop biomass with results from soil N tests. Drone technology could prove useful in predicting potential N from its biomass readings and stand counts, which is useful to improve decision making for timing cover crop termination. We will share our findings with farmers, crop consultants, and other researchers through interactive presentations, like ArcGIS Story Map, at Cooperative Extension events such as field days, Delaware Ag Week, or the Mid-Atlantic Crop Management School.

    Project objectives from proposal:

    The goal of this project is to use consumer drone technologies to quickly perform stand counts, assess cover crop biomass N potential, and identify fields where cover crop residue density may cause cash crop planting issues.

    Objective 1: Use drone technology to capture imagery of the cover crop mixes to approximate biomass and ground cover to help determine potential cover crop N.

    Research plots will be planted with rye, clover, and a rye clover mix at five different rates. We will scout the plots with a drone at various times throughout the season (i.e., up to two early season flights to observe fall cover crop stands, one flight during the winter, and bi-weekly flights in the spring until the cover crops are terminated).  Specialized cameras attached to the drone, will capture biomass imagery that will be analyzed on software that is easily accessible to farmers and crop consultants. We will determine the relationship cover crop biomass, soil N, and drone imagery. From this imagery a rate curve of biomass and N content will be developed.

    Objective 2: Verify the mathematical relationship between cover crops biomass and biomass available N from the research plots using data collected from farmer-planted cover crops.

    The drone derived biomass to N relationship determined in the research field trial (Objective 1) will be evaluated in farmer-planted cover crop stands. We will fly each field using the consumer drone and develop a map of the cover crop biomass. Samples collected from each field will be used to test the accuracy of the drone derived rate curve.

    Objective 3: Improve farmer productivity using rapid drone assessments to determine potential planting issues related to cover crop biomass.

    Thick cover crop residue can lead to cash crop planting issues and act as a mechanical barrier to seedling emergence (Loydi et al., 2012). We will compare stand counts taken in our research plots following corn planting to in-field biomass measurements and drone imagery to determine if cover crop biomass effects on final stands can be quickly measured through aerial imagery. Establishment of biomass residue thresholds will allow for better decision making on timing cover crop termination or adjusting planter settings, thereby reducing potential reseeding costs and increasing cash crop yields.

    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.