Abstract
Development of high-value horticultural markets for compost requires improved characterization of compost properties. Most composts have pH of 7–8 and act as a partial substitute for lime in potting media. The objective of this research was to develop and validate a reproducible method for determining the pH buffering capacity of compost. To estimate compost buffering capacity (CBC), the quantity of acidity needed to reduce pH by one unit, dilute sulfuric acid (H2SO4; 0.1–1.0 mol H+/kg compost) was allowed to equilibrate with compost at 22 °C for 72 h. The CBC was calculated as the negative reciprocal of the slope of the linear regression: compost pH (y-axis) versus acid addition rate (x-axis). The CBC for eight composts ranged from 0.21 to 0.45 mol H+ per kg compost per pH unit (avg = 0.31). The CBC determined from dilute acid addition for 72 h was validated via incubation of compost plus S° dust at 22 °C for 28 days. For the eight composts evaluated, S° addition to acidify compost by 1 pH unit (as predicted by CBC) resulted in an actual pH decline of 1.1 units (SE = 0.2), and predicted S° addition to acidify it by 2 pH units resulted in an actual decline of 1.7 units (SE = 0.2). The CBC test method is recommended for evaluation by commercial compost testing laboratories.
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Raviv, M.: The future of composts as ingredients of growing media. Acta Hortic. 891, 19–32 (2011)
Handreck, K., Black, N.: Growing Media for Ornamental Plants and Turf, 4th edn. University of New South Wales Press, Sydney (2010)
Sullivan, D.M., Miller, R.O.: Compost quality attributes, measurements and variability. In: Stofella, P.J., Kahn, B.A. (eds.) Compost Utilization in Horticultural Cropping Systems, pp. 95–120. CRC Press, Boca Raton (2001)
Thompson, W.H.P., Leege, P.M., Watson, M. (eds.): Test Methods for the Examination of Composting and Compost (TMECC). U.S. Composting Council (2001)
Stevenson, F.J.: Humus Chemistry: Genesis, Composition, Reactions. Wiley-Interscience, New York (1994)
Jeong, K.Y.: Establishment and stabilization of pH in container root substrate, pp. 21–41. M.S. Thesis. North Carolina State University (2010)
Martinez, F.X., Casasayas, R., Bures, S., Canameras, N.: Titration curves of different organic substrates. Acta Hortic. 221, 105–116 (1988)
García de la Fuente, R., Carrion, C., Botella, S., Fornes, F., Noguera, V., Abad, M.: Biological oxidation of elemental sulphur added to three composts from different feedstocks to reduce their pH for horticultural purposes. Bioresour. Technol. 98, 3561–3569 (2007)
Carrion, C., Carrion, C., Garcia de la Fuente, R., Fomes, F., Abad, M.: Acidifying composts from vegetable crop wastes to prepare growing media for containerized crops. Compost. Sci. Util. 16, 20–29 (2008)
Wong, M.T.F., Nortcliff, S., Swift, R.S.: Method for determining the acid ameliorating capacity of plant residue compost, urban waste compost, farmyard manure, and peat applied to tropical soils. Comm. Soil Sci. Plant Anal. 29, 2927–2937 (1998)
Costello, R.C.: Compost acidification increases growth and nutrient uptake of highbush blueberry under a low N fertilizer regime. In: Costello, R.C. (ed.) Suitability of Diverse Composts as Soil Amendments for Highbush Blueberry (Vaccinium corymbosum L.), pp. 15–47. M.S. Thesis. Oregon State University. Corvallis, OR. http://hdl.handle.net/1957/26590 (2011a)
Costello, R.C.: Evaluating diverse composts for highbush blueberry under an organic fertilization regime. In: Costello, R.C. (ed.) Suitability of Diverse Composts as Soil Amendments for Highbush Blueberry (Vaccinium corymbosum L.), pp. 48–79. M.S. Thesis. Oregon State University. Corvallis, OR. http://hdl.handle.net/1957/26590 (2011b)
Hart, J., Strik, B., White, L., Yang, W.: Nutrient Management for Blueberries in Oregon. EM8918. Oregon State University Extension, Corvallis, OR (2006)
Korcak, R.F.: Nutrition of blueberry and other calcifuges. Hortic. Rev. 10, 183–227 (1988)
Gavlak, R.G., Horneck, D.A., Miller, R.O.: Plant, Soil and Water Reference Methods for the Western Region, 2nd edn. Western Region Extension Publication 125 (WREP-125) (2003)
Warncke, D.D.: Analyzing greenhouse growth media by the saturation extract method. HortScience 21, 223–225 (1986)
James, B.R., Riha, S.J.: pH buffering in forest soil organic horizons: relevance to acid precipitation. J. Environ. Qual. 15, 229–234 (1986)
Magdoff, F.R., Bartlett, R.J., Ross, D.S.: Acidification and pH buffering of forest soils. Soil Sci. Soc. Am. J. 51, 1384–1386 (1987)
Curtin, D., Rostad, H.P.: Cation exchange and buffer potential of Saskatchewan soils estimated from texture, organic matter and pH. Can. J. Soil Sci. 77, 621–626 (1997)
Helling, C.S., Chesters, G., Corey, R.B.: Contribution of organic matter and clay to soil cation-exchange capacity as affected by the pH of the saturating solution. Soil Sci. Soc. Am. J. 28, 517–520 (1964)
Germida, J.J., Janzen, H.H.: Factors affecting the oxidation of elemental sulfur in soils. Nutr. Cycl. Agroecosyst. 35, 101–114 (1993)
VanderGheynst, J.S., Pettygrove, S., Dooley, T.M., Arnold, K.A.: Estimating electrical conductivity of compost extracts at different extraction ratios. Compost. Sci. Util. 12, 202–207 (2004)
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Costello, R.C., Sullivan, D.M. Determining the pH Buffering Capacity of Compost Via Titration with Dilute Sulfuric Acid. Waste Biomass Valor 5, 505–513 (2014). https://doi.org/10.1007/s12649-013-9279-y
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DOI: https://doi.org/10.1007/s12649-013-9279-y
Keywords
- Compost analysis
- Acidification
- Elemental S
- Lime
- Titration
- Potting media
- Acid loving plants
- Calcifuge
- Compost acidification requirement
- Dairy manure solids
- Deciduous tree leaves
- EC
- Electrical conductivity
- H+ buffering capacity
- H+ consumption capacity
- Horse manure
- Lime requirement
- Manure
- Organic matter
- Peat
- Peppermint
- Saturation extract method
- Soluble salt
- Straw
- Yard debris