|Author:||Michaud, A. R. ; Laverdière, M. R.|
|Book Group Author:||NA|
A simulated rainfall study was conducted on an array of 36 runoff plots (6 m2 each) deployed on three benchmark soil series of the Missisquoi region in southwestern Québec, Canada. The split-plot experimental design tested the effects and interactions of pig slurry treatment as main plots (check vs. 59 kg P ha-1) and cropping (tilled vs. hay) as subplots, on runoff volume and concentrations in total suspended sediment, total phosphorus (TP), dissolved reactive soluble P (DRP), particulate P (PP) and bioavailable P (BioP). TP concentration in runoff ranged from a low of 1.17 mg litre-1 average on non-amended Bedford hay, to a peak concentration average of 9.55 mg litre-1 on manured and tilled Saint-Sébastien plots. Variance analysis indicated significant contributions of treatments in explaining TP concentration in runoff as follows: soil type effect > cropping effect > soil × cropping interaction > manure effect. Erosion and sediment transport processes were identified as prime vectors of TP export. Manure effect alone accounted for 35% of overall DRP variability, while soil type alone accounted for 70% of variability in particulate P bioavailability (BioP/PP). Among practical implications of this study is the importance of assessing PP bioavailability to adequately predict the adverse impact of runoff on aquatic ecosystems. The high level of interaction among cropping and manure treatment and the site-specific influence of soil physical and chemical properties also calls for a holistic approach to nonpoint P risk assessment and management, that focusses on timely manure P management, control of soil P build-up and agricultural practices minimizing surface runoff.
|Pages:||295 - 305|
|Journal:||Canadian Journal of Soil Science|
bioavailability, cropping systems, erosion, phosphorus, pigslurry, rain, runoff, sediment, soil types, transport processes, Canada,Quebec, North America, America, Developed Countries, Commonwealth ofNations, OECD Countries, Canada, rainfall, soil transport processes,transport processes in soil systems, Plant Cropping Systems (FF150),Soil Chemistry and Mineralogy (JJ200), Erosion; Soil and WaterConservation (PP400), Animal Wastes (XX100)