Options for Improved Phosphorus Cycling and Use in Agriculture at the Field and Regional Scales.

Soil phosphorus (P) cycling in agroecosystems is highly complex, with many chemical, physical, and biological processes affecting the availability of P to plants. Traditionally, P fertilizer recommendations have been made using an insurance-based approach, which has resulted in the accumulation of P in many intensively managed agricultural soils worldwide and contributed to the widespread water quality issue of eutrophication. To mitigate further environmental degradation and because future P fertilizer supplies are threatened due to finite phosphate rock resources and associated geopolitical and quality issues, there is an immediate need to increase P use efficiency (PUE) in agroecosystems.

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.