Intensive agricultural production in the organic agricultural soils of the Holland Marsh (Ontario) contributes to the eutrophication of Lake Simcoe via heavy fertilizer use which in turn induces the release of nitrogen (N) and phosphorus (P) in the drainage waters. Drainage in the Holland Marsh is artificially managed and eventually discharges into Lake Simcoe. Nitrogen management has proven to be ineffective in the controlling of algal blooms, thus a reduction of phosphorus is critical to further managing eutrophication. Phosphorus (P) is an essential nutrient for horticultural crops in organic soils and newly cleared organic soils are low in plant-available P, prompting the addition of phosphorus fertilizers and resulting in nonpoint source P pollution from organic soil agricultural areas. The present research project is focused on examining the P dynamic transport in organic soil to mitigate non-point source P pollution and improve water quality. This will be achieved through the assessment of P water quality and soil analysis at multiple organic soil agricultural fields in the Holland Marsh to further the understanding of how the agricultural practices impact the P dynamics and outputs.
Objectives
1) Assessing the dynamics of P concentration in tile drainage and the spring P load emitted from these organic soil fields;
2) Determining how the initial soil P concentration and saturation, combined with fertilization and simulated rainfall, affects P leaching from organic soils;
3) Quantitative analysis of bioavailable P pool (in soil solution, microbial biomass and the crop), and its relationship to the P concentration in the drainage water of organic soils
4) Parameterize and validate a model for P dynamics in organic soils to optimize fertilizer and water applications that reduce the P concentration in tile drainage.
Research Team
Genevieve Grenon, PhD Student
Chandra A. Madramootoo, Supervisor
