Land Application of De-Inking Residue

Abstract

Pulp facilities which recycle office waste paper generate a large amount of waste by-products in the process of producing high-grade pulp. The paper-like substance, called de-inking residue, was evaluated for use as a soil amendment on land used for crop production in northeast Minnesota. Research plots were established in the fall of 1993 in Grand Rapids, Minnesota. The 10- by 20-foot plots were arranged in a randomized block design with 3 replications consisting of 3 levels of de-inking residue, 3 nitrogen rates, 1 manure rate, and 2 crops commonly produced in the region, for a total of 19 treatment combinations. Thirty-six lysimeters were installed to monitor changes in subsurface water quality. Soils were evaluated to determine impacts of de-inking residue on soil chemical properties. Crop yields and plant nutrient levels were determined in the late summer and early fall of 1994. De-inking residue was not a significant source of plant nutrients and cannot be classified as an Agricultural Liming Material (ALM). De-inking residue had a minimal impact on the chemical properties of soils and on subsurface water quality. The highest alfalfa yields typically occurred with the application of the following treatment combinations: 1) only nitrogen fertilizer, 2) nitrogen fertilizer with manure, 3) nitrogen fertilizer, manure, and 10 ton/acre de-inking residue, 4) 150 lb/acre nitrogen with 10 ton/acre de-inking residue applied in the fall, and 5) 300 lb/acre nitrogen with 10 ton/acre de-inking residue applied in the spring. The highest corn silage yields occurred with the application of the following treatment combinations: 1) no nitrogen, manure, or de-inking residue, applied in the spring, 2) only nitrogen fertilizer, 3) nitrogen fertilizer with manure, 4) spring application of 300 lb/acre nitrogen fertilizer with 10 ton/acre de-inking residue, 5) nitrogen fertilizer, manure and 10 ton/acre de-inking residue, and 6) 150 lb/acre nitrogen with 10 ton/acre de-inking residue applied in the fall. The alfalfa and corn plant analyses indicated that both nutrient and metal levels were within published sufficiency ranges, with few significant differences due to treatment effects.