title: Soil phosphorus loss in tile drainage water from long-term conventional- and non-tillage soils of Ontario with and without compost addition.
abstract: Recent ascertainment of tile drainage a predominant pathway of soil phosphorus (P) loss, along with the rise in concentration of soluble P in the Lake Erie, has led to a need to re-examine the impacts of agricultural practices. A three-year on-farm study was conducted to assess P loss in tile drainage water under long-term conventional- (CT) and non-tillage (NT) as influenced by yard waste leaf compost (LC) application in a Brookston clay loam soil. The effects of LC addition on soil P loss in tile drainage water varied depending on P forms and tillage systems. Under CT, dissolved reactive P (DRP) loss with LC addition over the study period was 765g P ha-1, 2.9 times higher than CT without LC application, due to both a 50% increase in tile drainage flow volume and a 165% increase in DRP concentration. Under NT, DRP loss in tile drainage water with LC addition was 1447gPha-1, 5.3 times greater than that for NT without LC application; this was solely caused by a 564% increase in DRP concentration. However, particulate P loads in tile drainage water with LC application remained unchanged, relative to non-LC application, regardless of tillage systems. Consequently, LC addition led to an increase in total P loads in tile drainage water by 57 and 69% under CT and NT, respectively. The results indicate that LC application may become an environmental concern due to increased DRP loss, particularly under NT.
authors.affiliation: Harrow Research and Development Centre, Agriculture and Agri-Food Canada, Harrow, ON N0R 1G0, Canada. Electronic address: Tiequan.Zhang@agr.gc.ca.
authors.forename: T Q
authors.initials: TQ
authors.lastname: Zhang
authors.affiliation: Harrow Research and Development Centre, Agriculture and Agri-Food Canada, Harrow, ON N0R 1G0, Canada.
authors.forename: C S
authors.initials: CS
authors.lastname: Tan
authors.affiliation: Harrow Research and Development Centre, Agriculture and Agri-Food Canada, Harrow, ON N0R 1G0, Canada.
authors.forename: Y T
authors.initials: YT
authors.lastname: Wang
authors.affiliation: Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6, Canada.
authors.forename: B L
authors.initials: BL
authors.lastname: Ma
authors.affiliation: Harrow Research and Development Centre, Agriculture and Agri-Food Canada, Harrow, ON N0R 1G0, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Welacky
keywords: Agricultural management practice; Organic amendments; Phosphorus; Sub-surface runoff; Surface water quality; Tile drainage