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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #223425
Title: Water treatment residuals and biosolids co-applications affect phosphatases in a semi-arid rangeland soil

Author
item BAYLEY, ROBIN - COLORADO STATE UNIVERSITY
item Ippolito, James
item STROMBERGER, MARY - COLORADO STATE UNIVERSITY
item BARBARICK, KENNETH - COLORADO STATE UNIVERSITY
item PASCHKE, MARK - COLORADO STATE UNIVERSITY

Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2008
Publication Date: 11/1/2008
Citation: Bayley, R.M., Ippolito, J.A., Stromberger, M.E., Barbarick, K.A., Paschke, M.W. 2008. Water treatment residuals and biosolids co-applications affect phosphatases in a semi-arid rangeland soil. Communications in Soil Science and Plant Analysis. 39:2812-2826.

Interpretive Summary: Biosolids and water treatment residuals (WTR) land co-application may be beneficial by sorbing excess biosolids-borne or soil P onto WTR, reducing the likelihood of off-site movement. Bayley et al. researched the long-term effects of single co-applications and the short-term impacts of repeated co-applications on soil acid phosphomonoesterase, phosphodiesterase, pyrophosphatase, and phytase enzyme activities. Soil phosphodiesterase activity decreased in WTR-amended plots, and pyrophosphatase activity decreased with increasing WTR application rates. In contrast, acid phosphatase and phytase activity increased with WTR addition, with WTR application possibly triggering a deficiency response causing microorganisms or plants to secrete these enzymes. Reductions in phosphodiesterase activity suggest less P mineralization from biomass sources, including nucleic acids and phospholipids. Increased acid phosphatase and phytase activities indicate that ester-P and inositol-P may be important plant-available P sources in soils amended with WTR.

Technical Abstract: Biosolids and water treatment residuals (WTR) land co-application has not been extensively studied, but may be beneficial by sorbing excess biosolids-borne or soil P onto WTR, reducing the likelihood of off-site movement. Reduction of excess soil P may affect the role of specific P-cleaving enzymes. The research objective was to understand the long-term effects of single co-applications and the short-term impacts of repeated co-applications on soil acid phosphomonoesterase, phosphodiesterase, pyrophosphatase, and phytase enzyme activities. Test plots were 7.5 × 15 m with treatments consisting of three different WTR rates with a single biosolids rate (5, 10, and 21 Mg WTR/ha; 10 Mg biosolids/ha) surface co-applied once in 1991 or re-coapplied in 2002. Control plots consisted of those which received no WTR-biosolids co-applications and plots which received only 10 Mg biosolids/ha. Plots were sampled to a 5-cm depth in 2003 and 2004 and soil phosphatases and phytase enzyme activities were measured. Soil phosphodiesterase activity decreased in WTR-amended plots, and pyrophosphatase activity decreased with increasing WTR application rates. In contrast, acid phosphatase and phytase activity increased with WTR addition, with WTR application possibly triggering a deficiency response causing microorganisms or plants to secrete these enzymes. Biosolids and WTR co-applications may affect enzymatic strategies for P mineralization in this study site. Reductions in phosphodiesterase activity suggest less P mineralization from biomass sources, including nucleic acids and phospholipids. Increased acid phosphatase and phytase activities indicate that ester-P and inositol-P may be important plant-available P sources in soils amended with WTR.