A Modified Ingrowth Core to Measure Root‐Rhizome Accumulation of Perennial Forage Species

Abstract

The ingrowth core method for measuring root accumulation has several advantages over sequential soil cores or mini‐rhizotrons. However, current ingrowth core designs are not well suited for use with rhizomatous perennial forage species or when defoliation occurs during the measurement period. Our objective was to develop a modified ingrowth core device and to evaluate its use for measuring root‐rhizome accumulation of a rhizomatous perennial forage in a hay management context. The modified ingrowth cores were constructed of 4‐mm polyester mesh surrounding a 7.5‐cm diameter cylinder constructed of cage wire. Field testing of the core design involved placing three ingrowth cores in each of four replicates of six treatments arranged in a randomized complete block design. Treatments consisted of six rhizoma peanut (Arachis glabrata Benth.) entries, and they were evaluated during 2017 and 2018. The ingrowth core design facilitated ease of placement, maintenance of core structural integrity throughout 100‐d deployment periods, rapid location of cores using a metal detector at the end of deployment periods, and precision to detect differences among treatments. We conclude that this modified ingrowth core design is well suited for measuring root‐rhizome accumulation rate of perennial forage species.Core Ideas Root or root‐rhizome biomass is the dominant C supply to grassland soils. There is little information on root‐rhizome accumulation rates under perennial forage crops. A modified root ingrowth core device was developed and tested in a field study. The modified core maintained structural integrity and successfully detected differences among treatments.