Modifications of the Minirhizotron Video Camera System for Measuring Spatial and Temporal Root Dynamics

Current video cameras used to measure in situ root activities lack essential registration and identification components for repeated accurate measurements. This report describes a rapid, inexpensive and completely portable approach for controlling and identifying camera position when making repeated video recordings from minirhizotrons in large field experiments. These registration handle and microcomputer additions to an agricultural microvideo color camera provide new opportunities for measuring root and nodule development. Preliminary measurements indicated that corn roots appeared and disappeared to depths of 75 cm for different N treatments 86 to 99 d after planting. Additionally, root development, maturation, and death can be observed in situ throughout the root profile. These modifications offer a uniform method for comparing root turnover rates and other specific dynamics of the rhizosphere at 1.2-cm intervals in contrasting soil and climatic conditions. MSU Agric. Exp. Stn. J. Article no. 12696, financially supported by federal grants 83-CRSR-2-2311 and BSR 8517985.