Phosphorus runoff from Canadian agricultural land: A dataset for 30 experimental fields.

Phosphorus (P) runoff from agricultural land plays a critical role in downstream water quality. This article summarizes P and sediment runoff data for both snowmelt and rainfall runoff from 30 arable fields in the Canadian provinces of Saskatchewan, Manitoba and Ontario. The data were collected from 216 site-years of field experiments, with climates ranging from semi-arid to humid and a wide range of field management practices.

Impacts of Cover Crops and Crop Residues on Phosphorus Losses in Cold Climates: A Review.

The use of cover crops and crop residues is a common strategy to mitigate sediment and nutrient losses from land to water. In cold climates, elevated dissolved P losses can occur associated with freeze-thaw of plant materials. Here, we review the impacts of cover crops and crop residues on dissolved P and total P loss in cold climates across ∼41 studies, exploring linkages between water-extractable P (WEP) in plant materials and P loss in surface runoff and subsurface drainage.

Impacts of Soil Phosphorus Drawdown on Snowmelt and Rainfall Runoff Water Quality.

Managing P export from agricultural land is critical to address freshwater eutrophication. However, soil P management, and options to draw down soil P have received little attention in snowmelt-dominated regions because of limited interaction between soil and snowmelt. Here, we assessed the impacts of soil P drawdown (reducing fertilizer P inputs combined with harvest removal) on soil Olsen P dynamics, runoff P concentrations, and crop yields from 1997 to 2014 in paired fields in Manitoba, Canada.

Agricultural Water Quality in Cold Climates: Processes, Drivers, Management Options, and Research Needs.

Cold agricultural regions are important sites of global food production. This has contributed to widespread water quality degradation influenced by processes and hydrologic pathways that differ from warm region analogues. In cold regions, snowmelt is often a dominant period of nutrient loss.

Nutrient Loss in Snowmelt Runoff: Results from a Long-term Study in a Dryland Cropping System.

Snowmelt runoff often comprises the majority of annual runoff in the Canadian Prairies and a significant proportion of total nutrient loss from agricultural land to surface water. Our objective was to determine the effect of agroecosystem management on snowmelt runoff and nutrient losses from a long-term field experiment at Swift Current, SK. Runoff quantity, nutrient concentrations, and loads were estimated after a change in management from conventionally tilled wheat ( L.

Global change pressures on soils from land use and management.

Soils are subject to varying degrees of direct or indirect human disturbance, constituting a major global change driver. Factoring out natural from direct and indirect human influence is not always straightforward, but some human activities have clear impacts. These include land-use change, land management and land degradation (erosion, compaction, sealing and salinization).

Conversion of Conservation Tillage to Rotational Tillage to Reduce Phosphorus Losses during Snowmelt Runoff in the Canadian Prairies.

In a preceding study, converting conventional tillage (ConvT) to conservation tillage (ConsT) was reported to decrease nitrogen (N) but to increase phosphorus (P) losses during snowmelt runoff. A field-scale study was conducted from 2004 to 2012 to determine if conversion of ConsT to rotational tillage (RotaT), where conservation tillage was interrupted by a fall tillage pass every other year, could effectively reduce P losses compared with ConsT. The RotaT study was conducted on long-term paired watersheds established in 1993.

Nutrient and sediment losses in snowmelt runoff from perennial forage and annual cropland in the canadian prairies.

An 8-yr field-scale study, 2005 to 2012, investigated effects of agricultural land use on nutrient and sediment losses during snowmelt runoff from four treatment fields in southern Manitoba. In 2005, two fields with a long-term history of annual crop (AC) production were planted to perennial forage (PF), while two other fields were left in AC production. In 2009, the AC fields were converted to PF, while the PF fields were returned to AC.

Herbicide transport in surface runoff from conventional and zero-tillage fields.

During the past four decades of crop production in the prairie region of Canada, there has been a dramatic shift from conventional management (CM) to conservation tillage management in which one or more tillage operations has been replaced by herbicide application. To determine whether this management shift has affected the quality of snowmelt runoff, field-scale side-by-side runoff watersheds were used in a 6-yr study. Herbicide concentrations and fluxes in snowmelt runoff water from CM and zero-till management (ZTM) systems were compared relative to an organic production system used as the control.

Critical factors affecting field-scale losses of nitrogen and phosphorus in spring snowmelt runoff in the canadian prairies.

A long-term, field-scale study in southern Manitoba, Canada, was used to identify the critical factors controlling yearly transport of nitrogen (N) and phosphorus (P) by snowmelt runoff. Flow monitoring and water sampling for total and dissolved N and P were performed at the edge of field. The flow-weighted mean concentrations and loads of N and P for the early (the first half of yearly total volume of snowmelt runoff), late (the second half of yearly total volume of snowmelt runoff), and yearly snowmelt runoff were calculated as response variables.

Brain weight-body weight ratio in sudden infant death syndrome revisited.

Aims: To determine whether the brain-body weight ratio is increased in sudden infant death syndrome (SIDS).

Methods: Review of autopsy files from Forensic Science SA, South Australia was undertaken over an eight-year period from 1999 to 2006, with classification of cases according to the San Diego definition. Sudden and/or unexpected deaths in previously healthy infants due to asphyxia or infection were selected as controls.

Leaching of three imidazolinone herbicides during sprinkler irrigation.

Some imidazolinone herbicides have been shown to be mobile in soil, raising concern about their possible movement to ground water. Three imidazolinone herbicides (imazamethabenz-methyl, 497 g ha(-1); imazethapyr, 14.7 g ha(-1); and imazamox, 14.

The effects of multiple beneficial management practices on hydrology and nutrient losses in a small watershed in the Canadian prairies.

Most beneficial management practices (BMPs) recommended for reducing nutrient losses from agricultural land have been established and tested in temperate and humid regions. Previous studies on the effects of these BMPs in cold-climate regions, especially at the small watershed scale, are rare. In this study, runoff and water quality were monitored from 1999 to 2008 at the outlets of two subwatersheds in the South Tobacco Creek watershed in Manitoba, Canada.

Leaching of three sulfonylurea herbicides during sprinkler irrigation.

Sulfonylurea herbicides are widely applied on the Canadian prairies to control weeds in a variety of crops. Several sulfonylurea herbicides are mobile in soil, and there is concern about their possible movement to ground water. This study was performed to assess the susceptibility of three sulfonylurea herbicides commonly used in prairie crop production to leach under a worst-case scenario.

Transport of lincomycin to surface and ground water from manure-amended cropland.

Livestock manure containing antimicrobials becomes a possible source of these compounds to surface and ground waters when applied to cropland as a nutrient source. The potential for transport of the veterinary antimicrobial lincomycin to surface waters via surface runoff and to leach to ground water was assessed by monitoring manure-amended soil, simulated rainfall runoff, snowmelt runoff, and ground water over a 2-yr period in Saskatchewan, Canada, after fall application of liquid swine manure to cropland. Liquid chromatography tandem mass spectrometry was used to quantify lincomycin in all matrix extracts.

Seasonal variation of herbicide concentrations in prairie farm dugouts.

Prairie farm dugouts are frequently constructed for use as potable water sources. Consequently, cumulative pesticide inputs via atmospheric deposition and surface runoff may constitute a risk to human health. Since, relative to other pesticides, herbicides are used in greatest amount on the Canadian prairies, herbicide concentrations were intensively monitored in three dugouts over three growing seasons.