42 research outputs found

    Effects of watershed land use on nitrogen concentrations and δ15 Nitrogen in groundwater

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    Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Biogeochemistry 77 (2006): 199-215, doi:10.1007/s10533-005-1036-2.Eutrophication is a major agent of change affecting freshwater, estuarine, and marine systems. It is largely driven by transportation of nitrogen from natural and anthropogenic sources. Research is needed to quantify this nitrogen delivery and to link the delivery to specific land-derived sources. In this study we measured nitrogen concentrations and δ15N values in seepage water entering three freshwater ponds and six estuaries on Cape Cod, Massachusetts and assessed how they varied with different types of land use. Nitrate concentrations and δ15N values in groundwater reflected land use in developed and pristine watersheds. In particular, watersheds with larger populations delivered larger nitrate loads with higher δ15N values to receiving waters. The enriched δ15N values confirmed nitrogen loading model results identifying wastewater contributions from septic tanks as the major N source. Furthermore, it was apparent that N coastal sources had a relatively larger impact on the N loads and isotopic signatures than did inland N sources further upstream in the watersheds. This finding suggests that management priorities could focus on coastal sources as a first course of action. This would require management constraints on a much smaller population.This work was supported by funds from the Woods Hole Oceanographic Institution Sea Grant Program, from the Cooperative Institute for Coastal and Estuarine Environmental Technology, from Massachusetts Department of Environmental Protection to Applied Science Associates, Narragansett, RI, as well as from Palmer/McLeod and NOAA National Estuarine Research Reserve Fellowships to Kevin Kroeger. This work is the result of research sponsored by NOAA National Sea Grant College Program Office, Department of Commerce, under Grant No. NA86RG0075, Woods Hole Oceanographic Institution Sea Grant Project No. R/M-40

    Pea (Pisum sativum) and faba beans (Vicia faba) in dairy cow diet: effect on milk production and quality

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    The use of alternative plant proteins in place of the soybean meal protein in diets for producing animals aims to reduce the extra-EU soybean import and partially substitute the GMO in the food chain. Among possible alternatives, the heat-processed legume grains seem interesting for dairy cow diets. Two consecutive experiments were carried out to evaluate flaked pea and faba beans as substitute for soybean meal in diets for Reggiana breed dairy cows producing milk for Parmigiano- Reggiano cheese-making. In both experiments a C concentrate (110 g/kg soybean meal, no pea and faba beans) was compared to a PF concentrate (150 g/kg flaked pea, 100 g/kg flaked faba beans, no soybean meal). Forages fed to animals were hay (mixed grass and alfalfa) in experiment 1 and hay plus mixed grass in experiment 2. Concentrate intake, milk yield and milk quality (rennet coagulation traits included) were similar between feeding groups. Parameters on the grab faecal samples, as empirical indicators of digestibility, had a smaller (P<0.01) amount of residual concentrate in the PF group compared to the C group (2.4 vs 3.1 and 2.3 vs 2.8%, respectively for PF and C in experiment 1 and 2). Some blood indicators of nitrogen metabolism (protein, albumin, urea) were similar between the feeding groups.The inclusion of pea and faba beans, within the allowed limit of the Parmigiano-Reggiano Consortium for diet formulation, could represent a feasible opportunity for a total substitution of soybean
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