Effects of Biochar Treatment of Municipal Biosolids and Horse Manure on Quality of Runoff from Fescue Plots

Abstract

Land-applied horse manure and municipal biosolids can increase nutrient and bacteria concentrations in runoff. Biochar has been demonstrated to have beneficial impacts on nutrient retention and runoff quality when used to treat other land-applied organic soil amendments (e.g., poultry manure). The objective of this study was to evaluate the effects of biochar addition to horse manure and municipal biosolids on runoff concentrations of nutrients and fecal coliforms. Biochar was added at 5% to 8% (wet basis) to horse manure and biosolids that were applied to 2.4 m  6.1 m fescue plots followed by application of simulated rainfall (102 mm h-1). Analysis of runoff samples indicated that soil hydraulic characteristics, as reflected in the runoff curve number (CN), were a significant covariate for some analytical parameters. Analysis of covariance indicated that biochar addition decreased runoff concentrations of total Kjeldahl nitrogen (TKN) and ammonia nitrogen (NH 3-N) when added to municipal biosolids, with all effects more prominent at higher CN values. When added to horse manure, biochar decreased runoff concentrations of NH 3-N, total suspended solids, and fecal coliforms. Although runoff concentrations of total P and TKN increased with CN, there was no significant biochar effect on these parameters when added to horse manure. The findings indicate potential for biochar addition to improve runoff quality when added to these organic amendments, but the effects may be dependent on the receiving soil's runoff production characteristics.

Current Research in Land, Water, and Agroecosystems: ASABE Journals 2017 Year in Review

“…A setback distance of 12.2 m on no-till cropland in Nebraska with 7.7 Mg ha -1 residue and 5% slope was found to reduce runoff concentrations of N, dissolved P, and K, among other constituents, to background levels (Gilley et al, 2017). Biochar added to horse manure or municipal biosolids at 5% to 8% (wet basis) improved runoff quality but had significant covariation with runoff curve number (CN) for some parameters (Williams and Edwards, 2017).…”

“…While many water quality studies were discussed in other sections, e.g., agricultural drainage (Steppuhn and McArthur, 2017;Kaleita, 2017a, 2017b), crop modeling (Fang et al, 2017b), climate change Renkenberger et al, 2017;Wallace et al, 2017;Yasarer et al, 2017), land application of livestock waste (Gilley et al, 2017;Schuster et al, 2017;Williams and Edwards, 2017), forest resource management (Muwamba et al, 2017), and international watershed technology (Conte and Ahmadi, 2017;Muenich et al, 2017), additional studies addressed nutrient transport and water quality modeling.…”