The effects of ferulic acid on the mineral nutrition of grain sorghum

The combined effects of whole-tree harvesting (WTH) and soil leaching by both acid deposition and naturally-produced carbonic acid were evaluated in a mixed oak and a loblolly pine forest growing on similar soils in the Ridge and Valley province of eastern Tennessee. It was hypothesized that nutrient export via WTH would be greater in a mixed oak stand than in the loblolly pine stand because of greater nutrient concentrations in oak and hickory species than in pine. This hypothesis was true for N,P, and particularly Ca at the time of harvest, but not for K or Mg. When expressed on an annual basis, exports of N,P,K, and Mg were greater in the loblolly pine site and only Ca export was greater in the mixed oak site. It was also hypothesized that the large accumulation of Ca in the oak and hickory vegetation would cause lower exchangeable Ca²⁺ in soils, and, consequently, lower Ca²⁺ leaching in the mixed oak site than in the loblolly pine site. This hypothesis was supported by the data, which indicated 340–370% more exchangeable Ca and 100% more Ca²⁺ leaching in the loblolly pine site than in the mixed oak site. Research sponsored by the U.S. Environmental Protection Agency under Interagency Agreement No. 79-D-X0533 and Biofuels and Municipal Waste Technology Division, U.S. Department of Energy, under Contract No. De-AC05-84OR21400 with Martin Marietta Energy Systems, Inc. Publication No. 2933, Environmental Sciences Division, ORNL.