Biosolids Applications Affect Runoff Water Quality following Forest Fire
Dep. of Rangeland Ecosystem Science, Colorado State Univ., Fort Collins 80523, USA. Journal of Environmental Quality
(Impact Factor: 2.65).
09/2001; 30(5):1528-32. DOI: 10.2134/jeq2001.3051528x
Soil erosion and nutrient losses are great concerns following forest wildfires. Biosolids application might enhance revegetation efforts while reducing soil erodibility. Consequently, we applied Denver Metro Wastewater District composted biosolids at rates of 0, 40, and 80 Mg ha(-1) to a severely burned, previously forested site near Buffalo Creek, CO to increase plant cover and growth. Soils were classified as Ustorthents, Ustochrepts, and Haploborols. Simulated rainfall was applied for 30 min at a rate of 100 mm h(-1) to 3- x 10-m paired plots. Biosolids application rates did not significantly affect mean total runoff (p < 0.05). Sediment concentrations were significantly greater (p < 0.05) from the control plots compared with the plots that had received the 80 Mg biosolids ha(-1) rate. Biosolids application rate had mixed effects on water-quality constituents; however, concentrations of all runoff constituents for all treatment rates were below levels recommended for drinking water standards, except Pb. Biosolids application to this site increased plant cover, which should provide erosion control.
Available from: Mark Gerard Healy
- "They can be used as an aid in the development of a soil's physical and chemical characteristics. They increase water absorbency and tilth and may reduce the possibility of soil erosion (Meyer et al. 2001). Land application of biosolids and MBM to agricultural land can be relatively inexpensive in countries such as the Republic of Ireland (hereafter referred to as Ireland) and the USA, as such byproducts are defined as wastes. "
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ABSTRACT: The aim of this study was to develop (1) a method for the calculation of the maximum legal rate at which meat and bone meal (MBM) and biosolids should be applied to land, which took into account the soil phosphorus (P) index, the dry solids and the nutrient and metal content of each material, and (2) a quick method to evaluate their impact, when applied at the estimated maximum and twice the maximum application rates, on the release of P and metals to surface runoff. Three types of biosolids—lime stabilised (LS), anaerobically digested (AD) and thermally dried (TD)—and two types of MBM (low and high ash) were examined. The nutrient and metal losses were examined using a 1-L capacity beaker, which contained an intact soil core. Treatments were applied at maximum and twice the maximum legal application rates and then overlain with 500 mL of water, which was stirred to simulate overland flow. At the maximum legal application rate, low ash MBM (1.14 mg L−1) and TD biosolids (2.43 mg L−1) had the highest losses of P. Thermally dried biosolids and LS biosolids exceeded maximum allowable concentrations (MAC) for manganese, but all treatments remained below the MAC for copper and iron, at the maximum legal application rate. Anaerobically digested biosolids and high and low ash MBM would appear to have potential for landspreading, but these results are indicative only and should be verified at field scale.
- "Under these circumstances, even a mild rainstorm event potentially can cause significant moisture runoff, soil erosion, and surface water impairment. Land reclamation field work conducted on the Buffalo Creek, Colorado, wildfire site demonstrated that biosolids land application on steep forested slopes (25 to 50%) was capable of (1) increasing vegetative productivity, (2) decreasing soil erosion potential, and (3) increasing biodiversity (Meyer et al., 2001). Biosolids land-applied at one-time rates of 0 (control) up to 80 metric tons/ha were tilled (disked) on the wildfire burn site, which was then followed by reseeding with a mixture of native grasses (i.e., slender wheatgrass [Elymus trachycaulus], thickspike wheatgrass [Elymus macrourus], streambank wheatgrass and green needle grass [Nassella viridula], mountain brome [Bromus marginatus], Canby bluegrass [Poa canbyi], Idaho fescue [Festuca idahoensis], and Arizona fescue [Festuca arizonica]). "
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ABSTRACT: Biosolids land application was demonstrated to be a potentially cost-effective means for restoring forage productivity and enhancing soil-moisture-holding capacity on disturbed rangelands. By land-applying aerobically digested, anaerobically digested, composted, and lime-stabilized biosolids on rangeland test plots at rates of up to 20 times (20X) the estimated nitrogen-based agronomic rate, forage yields were found to increase from 132.8 kg/ha (118.2 lb/ac) (control plots) to 1182.3 kg/ha (1052.8 lb/ac). Despite the environmental benefits associated with increased forage yield (e.g., reduced soil erosion, improved drainage, and enhanced terrestrial carbon sequestration), the type of forage generated both before and after biosolids land application was found to be dominated by invasive weeds, all of which were characterized as having fair to poor nutritional value. Opportunistic and shallow rooting invasive weeds not only have marginal nutritional value, they also limit the establishment of native perennial grasses and thus biodiversity. Many of the identified invasive species (e.g., Cheatgrass) mature early, a characteristic that significantly increases the fuel loads that support the increased frequency and extent of western wildfires.
Available from: David Tarrasón
- "For this reason, it is important to understand the dynamics of nitrogen contribution from sludge in order to adjust dosages to the real crop's needs. Sludge can also be used to restore land degraded by mining activity (Sort and Alcañ iz, 1996; Tedesco et al., 1999) or forest fires (Meyer et al., 2001). Care should also be exercised in these cases where sludge doses are relatively high in order to prevent the eutrophication of water bodies in these areas. "
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ABSTRACT: Anaerobically-digested sludge called fresh sludge (F), composted sludge (C) and thermally-drying sludge (T), all from the same batch, were applied to the surface of a calcareous Udic Calciustept with loamy texture. Dosage equivalent was 10 t ha(-1) of dry matter. The concentration of mineral nitrogen (ammonium and nitrate) in the soil was measured in order to estimate the effects of the post-treatments to which the different kinds of sewage sludge are subjected in relation to the availability of N in the surface layer of the soil. The most significant differences in NH(4)-N and NO(3)-N concentrations due to the transformation of the organic matter were observed during the first three weeks following soil amendment. Thermally-dried and composted sludge initially displayed higher concentrations of ammonium and nitrate in soil. Five months after the amendment, soil applied with fresh sludge showed the highest concentrations of NH(4)-N and NO(3)-N (6.1 and 36.6 mg kg(-1), respectively). It is clear that the processes of composting and thermal-drying influence the bioavailability of nitrogen from the different types of sewage sludge.
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