Potato response to struvite compared with conventional phosphorus fertilizer in Eastern Canada
Rim Benjannet, Judith Nyiraneza, Lotfi Khiari, Athyna N. Cambouris, Keith Fuller, Sheldon Hann, Noura Ziadi
Abstract
Abstract In acidic soils with high phosphorus (P) fixing capacity, P application at levels higher than crop requirements is common in crops with high P demands such as potato ( Solanum tuberosum L.), which could lead to eutrophication. Recycled sources of P fertilizer, such as struvite, can be efficient in meeting crop P demands while minimizing P losses. The objective of this study—conducted in four provinces over 3 yr (2016–2018, with 12 sites in total) in Eastern Canada—was to assess potato response to P fertilizer as triple superphosphate (TSP) or a mixture of TSP with struvite. Eight P treatments were applied with five increasing P rates as TSP (0, 26, 52, 79, and 105 kg P ha −1 ) and three treatments as a mixture of TSP and struvite (25, 50, and 75% (w/w) struvite) at a rate of 79 kg P ha −1 . Phosphorus availability indices measured multiple times over the growing season were composed of Mehlich‐3 extracted P (P M3 ), soil P adsorbed on anion exchange membranes (P AEMs ), and petiole P‐PO 4 (P petiole ) concentrations. There was a potato yield response to P inputs at all sites, with the control treatment showing lower potato yield at all sites. Potato yield, P petiole , P M3 , and P AEMs were comparable between 100% TSP and TSP+struvite at the same rate, except at one site where struvite at a higher proportion depressed yield and was associated with lower P uptake. Overall, the use of struvite could be a sustainable mean to address long‐term globally P scarcity.