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Water treatment residuals and biosolids long-term co-applications effects to semi-arid grassland soils and vegetation

Ippolito, J.A. and Barbarack, K.A. and Stromberger, M.E. and Paschke, M.W. and Brobst, R.B. (2009) Water treatment residuals and biosolids long-term co-applications effects to semi-arid grassland soils and vegetation. Soil Science Society of America Journal. 73(6):1880-1889.

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Water treatment residuals (WTRs) and biosolids are byproducts from municipal water treatment
processes. Both byproducts have been studied separately for land application benefits. There
are possible environmental benefits of WTRs and biosolids co-application but these studies
are limited. Our objectives were to determine relative long-term (13–15 yr) effects of a single
and short-term (2–4 yr) effects of repeated WTR-biosolids co-applications on soil chemistry,
microbiology, and plant community structure in a Colorado semiarid grassland. Only relative
changes associated between co-applications were studied, as we assumed WTR application would
only occur if used as a management practice. Three WTR rates (5, 10, and 21 Mg ha–1) were surface
co-applied (no incorporation) with a single biosolids rate (10 Mg ha–1) once in 1991 (long-term
plots) and again in 2002 (short-term plots). Soil 0- to 8-, 8- to 15-, and 15- to 30-cm depth pH,
electrical conductivity (EC), NO3–N, NH4–N, total C, and total N were not aff ected by WTR
application in 2004, 2005, or 2006. Ammonium-bicarbonate diethylenetriaminepentaacetic
acid (AB-DTPA)- extractable soil Al was unaffected by WTR application, but extractable P and
Mo decreased with increasing WTR rate because of WTR adsorption. Plant tissue P and Mo
content decreased with specific plant species and years due to adsorption to WTR; no deficiency
symptoms were observed. Plant community composition and cover were largely unaffected by
WTR application. Soil microbial community structure was unaffected by WTR co-application
rate (total ester-linked fatty acid methyl ester [EL-FAME] concentrations ranged from 33.4 to
54.8 nmol g–1 soil), although time since biosolids-WTR application affected a subset of microbial
community fatty acids including markers for Gram-positive and Gram-negative bacteria. Overall,
WTR-biosolids co-applications did not adversely affect semiarid grassland ecosystem dynamics.

Item Type: Article
NWISRL Publication Number: 1325
Subjects: Irrigated crops > Grass forage
Depositing User: Users 6 not found.
Date Deposited: 30 Nov 2009 22:31
Last Modified: 14 Oct 2016 14:55
Item ID: 1348