Nitrogen leaching in paper‐amended soil columns

Abstract

In the southeastern United States, productivity of sandy, poorly structured soils could be improved by increasing organic matter content. Organic matter can be increased by adding waste paper with either nitrogen (N) fertilizer or poultry litter (PL) to adjust the carbon (C) to nitrogen ratio. Our objective was to compare N leached when ammonium nitrate (AN) or PL was added to 30‐cm‐deep, 20‐cm‐diameter soil columns amended with waste paper. We established soil columns with three treatments in the Ap horizon over three treatments in the E horizon in nine treatment combinations. No plants were grown. The Ap horizon treatments were AN plus waste paper, PL plus waste paper, and nothing added. Additions were balanced to a 20:1 C to N ratio. The E horizon treatments were waste paper mixed, waste paper on the column axis (not mixed), and nothing added. The experiment was run in 1993 and 1994. Columns were leached with 500 ml (1.5 cm) of deionized water two or three times a week. For both trials of the experiment, more N leached from AN plus paper (2.39 g) than from PL plus paper (0.36 g) or the nothing‐added (0.24 g) Ap treatments. This result reflects more N available for leaching from the AN treatment. Increased leaching of N can limit growth and deteriorate groundwater quality. In 1994, we measured 0.48, 0.30, and 0.97 g of N in the effluent from paper mixed, not mixed, and no paper added to the E horizon, respectively. Less N leached from columns with paper in the E horizon. For E horizons with paper, less leaching of N and higher N contents at the end of the experiment suggest that paper held some N preventing it from leaching.