Solubility of phosphorus and heavy metals in potting media amended with yard waste-biosolids compost

• Published in: Journal of environmental quality 2004-01, Vol.33 (1), p.373-379
• Main Authors: Zhang, M.K, He, Z.L, Stoffella, P.J, Calvert, D.V, Yang, X.E, Xia, Y.P, Wilson, S.B
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Air pollution; Aluminum; Applied sciences; Biological and medical sciences; Biological and physicochemical phenomena; Biosolids; biosolids composts; Cadmium; Chromium; Composting; Composts; Copper; Crop production; Crops; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental effects; Environmental impact; Environmental perception; Exact sciences and technology; Fertilizers; Fractionation; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Greenhouse effect; greenhouse production; Groundwater pollution; growing media; Heavy metals; Humans; Iron; Leaching; Lead (metal); Media; Metals; Metals, Heavy - chemistry; Natural water pollution; Nickel; Organic phosphorus; Other industrial wastes. Sewage sludge; Other nutrients. Amendments. Solid and liquid wastes. Sludges and slurries; Peat; Phosphorus; Phosphorus - chemistry; Plant growth; Pollution; Pollution, environment geology; Refuse Disposal; Risk; Sodium hydroxide; Soil; soil amendments; soil pH; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Solubility; Wastes; Water Pollutants, Chemical; Water pollution; water solubility; Water treatment and pollution; Yard waste; yard waste composts
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2004.3730

The potential risk of surface and ground water contamination by phosphorus (P) and heavy metals leached from compost-based containerized media has become an environmental concern. Solubility and fractionation of P and heavy metals were evaluated in media containing 0, 25, 50, 75, or 100% compost derived from biosolids and yard trimmings for potential impacts on the environment. As compost proportion in peat-based media increased from 0 to 100%, concentrations of total P, Cd, Cu, Ni, Pb, Zn, and Mn in the media increased whereas concentrations of total Co and Cr decreased. Except for Cu, all heavy metals in the water-soluble fraction decreased with increasing compost proportion in the media, because of higher Fe, Al, and Ca concentrations and pH values of the composts than the peat. When the media pH is controlled and maintained at normal range of plant growth (5.5-6.5), leaching of the heavy metals is minimal. Incorporation of compost to the peat-based media also decreased the proportion of total P that was water-soluble. However, concentrations of bioavailable inorganic phosphorus (NaHCO3-IP), readily mineralizable organic phosphorus (NaHCO3-OP), potentially bioavailable inorganic phosphorus (NaOH-IP), and potentially bioavailable organic phosphorus (NaOH-OP) were still higher in the media amended with compost because of higher total P concentration in the compost. Further study is needed to verify if less or no topdressing of chemical P fertilizer should be applied to the compost-amended media to minimize P effect on the environment when compost-amended potting media are used for nursery or greenhouse crop production systems.