title: Drainage water management combined with cover crop enhances reduction of soil phosphorus loss.
abstract: Integrating multiple practices for mitigation of phosphorus (P) loss from soils may enhance the reduction efficiency, but this has not been studied as much as individual ones. A four-year study was conducted to determine the effects of cover crop (CC) (CC vs. no CC, NCC) and drainage water management (DWM) (controlled drainage with sub-irrigation, CDS, vs. regular free tile drainage, RFD) and their interaction on P loss through both surface runoff (SR) and tile drainage (TD) water in a clay loam soil of the Lake Erie region. Cover crop reduced SR flow volume by 32% relative to NCC, regardless of DWM treatment. In contrast, CC increased TD flow volume by 57 and 9.4% with CDS and RFD, respectively, compared to the corresponding DWM treatment with NCC. The total (SR+TD) field water discharge volumes were comparable amongst all the treatments. Cover crop reduced flow-weighted mean (FWM) concentrations of particulate P (PP) by 26% and total P (TP) by 12% in SR, while it didn't affect the FWM dissolved reactive P (DRP) concentration, regardless of DWM treatments. Compared with RFD, CDS reduced FWM DRP concentration in TD water by 19%, while CC reduced FWM PP and TP concentrations in TD by 21 and 17%, respectively. Total (SR+TD) soil TP loss was the least with CDS-CC followed by RFD-CC, CDS-NCC, and RFD-NCC. Compared with RFD-NCC, currently popular practice in the region, total TP loss was reduced by 23% with CDS-CC. The CDS-CC system can be an effective practice to ultimately mitigate soil P loading to water resource.
authors.affiliation: Harrow Research and Development Center, 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 Center, 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 Center, Agriculture and Agri-Food Canada, Harrow, ON N0R 1G0, Canada.
authors.forename: Z M
authors.initials: ZM
authors.lastname: Zheng
authors.affiliation: Harrow Research and Development Center, Agriculture and Agri-Food Canada, Harrow, ON N0R 1G0, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Welacky
authors.affiliation: Harrow Research and Development Center, Agriculture and Agri-Food Canada, Harrow, ON N0R 1G0, Canada.
authors.forename: Y T
authors.initials: YT
authors.lastname: Wang
keywords: Cover crop; Drainage water management; Phosphorus; Surface runoff; Surface water quality; Tile drainage