Growth of corn roots under low-input and conventional farming systems

Abstract

AbstractChanges in soil physical and chemical properties following conversion from conventional to low-input farming systems could alter root growth in com and hence aboveground growth and yield. The main hypothesis we tested is that low-input and conventional farming systems produce different amounts of corn roots. We compared low-input and conventional farming systems, row position (row and interrow), and soil depth for effects on root length density in a Comly silt loam (Typic Fragiudalf) at the Rodale Institute Research Center in Kutztown, Pennsylvania. On all sampling dates studied (two each in 1989 and 1990) root length density under low-input farming systems was significantly greater than under conventional farming systems. We used analysis of covariance to correct for soil factors that could not be directly controlled. Soil water and bulk density had no clear effect on root length density. In contrast, there was significant covariance of soil organic matter with root length density on two of the four sample dates. Root networks were more dense in soil pockets rich in organic matter for every farming system, row position, and depth. These findings indicate that low-input farmers may be manipulating root production of corn to allow com to absorb more nutrients and water when water in the topsail is limited.