Potato response to struvite compared with conventional phosphorus fertilizer in Eastern Canada

Phosphate rock (PR) is not a renewable resource and nearly 82% of global PR is used for phosphorus fertilizer production with over 1 million tons consumption yearly. However, conventional P fertilizers are highly water-soluble and can potentially raise P concentrations in the soil solution and sediment particulary in Atlantic Canada, with its high annual preciptation and rolling topography. Research initiatives to find sustainable solutions that mitigate P-related impacts on the environment and reduce dependence on industrial fertilizers are needed. One solution is the use of recycled P from waste materials (struvite), an environmentally sound P source. Struvite has low solubility in water and its dissolution is enhanced by organic acids released by crop roots. This study conducted in four provinces (Prince Edward Island, New Brunswick, Nova Scotia and Quebec) over three years (2016–2018, with 12 sites in total) assessed potato response to P fertilizer as triple superphosphate (TSP) or a mixture of TSP with struvite in proportion of 25%, 50% or 75%. Phosphorus plant or soil-related P availability indices were measured multiple times over the growing season to assess P dynamics. Pure conventional fertilizer as TSP or a mixture of struvite with TSP in different proportions performed equally in increasing potato yields or in releasing P over the growing season except at one site where struvite at higher proportion depressed yield and was associated with lower P uptake (PU) in comparison to 100%TSP. Overall, the use of struvite could be a sustainable mean to address long-term globally P scarcity.