S.C. Komor 1997 <p><span>Boron-isotope (&delta;</span>¹¹<span>B) values may be useful as surrogate tracers of contaminants and indicators of water mixing in agricultural settings. This paper characterizes the B contents and isotopic compositions of hog manure and selected fertilizers, and presents &delta;</span>¹¹<span>B data for ground and surface water from two agricultural areas. Boron concentrations in dry hog manure averaged 61 mg/kg and in commercial fertilizers ranged from below detection limits in some brands of ammonium nitrate and urea to 382 mg/kg in magnesium sulfate. Values of &delta;</span>¹¹<span>B of untreated hog manure ranged from 7.2 to 11.2o/oo and of N fertilizers were &minus;2.0 to 0.7o/oo. In 22 groundwater samples from a sand-plain aquifer in east-central Minnesota, B concentrations averaged 0.04 mg/L and &delta;</span>¹¹<span>B values ranged from 2.3 to 41.5o/oo. Groundwater beneath a hog feedlot and a cultivated field where hog manure was applied had B-isotope compositions consistent with the water containing hog-manure leachate. In a 775-km</span>²<span>&nbsp;watershed with silty-loam soils in southcentral Minnesota: 18 samples of subsurface drainage from corn (</span><i>Zea mays</i><span>&nbsp;L.) and soybean (</span><i>Glycine max</i><span>&nbsp;L. Merr.) fields had average B concentrations of 0.06 mg/L and &delta;</span>¹¹<span>B values of 5.3 to 15.1o/oo; 27 stream samples had average B concentrations of 0.05 mg/L and &delta;</span>¹¹<span>B values of 1.0 to 19.0o/oo; and eight groundwater samples had average B concentrations of 0.09 mg/L and &delta;</span>¹¹<span>B values of &minus;0.3 to 23.0o/oo. Values of &delta;</span>¹¹<span>B and B concentrations, when plotted against one another, define a curved mixing trend that suggests subsurface drainage and stream water contain mixtures of B from shallow and deep groundwater.</span></p> application/pdf 10.2134/jeq1997.00472425002600050004x en American Soc of Agronomy Inc Boron contents and isotopic compositions of hog manure, selected fertilizers, and water in Minnesota article