Corn root‐Configuration Response to Soil Temperature and Matric Suction1

Abstract

Soil temperature and water variables imposed on the roots of corn (Zea mays L.) in field plots influenced root development. Responses were measured in separate portions of the root system where adventitious roots initiate and subsequent root elongation and branching occurs. These portions of the corn root system are separated far enough to permit specific field management for each portion. Temperature and water variables were produced by combinations of straw‐mulch strips and interrow tillage.Initiation of adventitious roots in the 0‐ to 10‐cm soil depth was dominantly influenced by soil temperature in the row.In soil depths below 10 cm, a functional relation between root configuration and the interrow‐minus‐row soil temperature, and matric suction described the elongation and branching responses subsequent to root initiation. In the year of lower soil temperature and higher moisture (measurements were made in two growing seasons), higher interrow temperatures stimulated branching and elongation, but in the year of higher soil temperature and moderate moisture conditions, responses to temperature were negligible. Higher interrow moisture stimulated branching and elongation in both years as long as the average matric suction was greater than about 85 mb.These explicit descriptions of corn‐root‐configuration response show the importance of soil temperature management in the row and water management in the interrow. This approach permits more extensive use of the row‐interrow concept for design of minimum tillage and residue management systems.