Wastewater‐recovered struvite effects on total extractable phosphorus compared with other phosphorus sources

Abstract

Intentional precipitation of the phosphorus (P)‐containing mineral struvite (MgNH4PO4 · 6H2O) is an attractive option in sustainable water management due to the ability to recover P from various waste sources. Limited research has assessed struvite's potential as a fertilizer P source in agronomic soils compared with other conventional fertilizer P sources under flooded soil conditions, common for lowland rice (Oryza sativa L.). The objective of this study was to evaluate total extractable soil P over time from a wastewater‐recovered struvite (ST) material in a plant‐less soil incubation with two silt‐loam (SiL) and a silty clay loam (SiCL) soil in a flooded soil environment compared to monoammonium phosphate (MAP) and triple superphosphate (TSP). Replicated soil cups were amended at a rate of 24.5 kg P ha–1 and were sampled after 0.5, 1, 2, 3, and 4 mo. Total water‐soluble (WS) soil P concentrations increased the most from the initial in the ST treatment (69.9 and 52.2 mg kg–1 after 0.5 and 1 mo, respectively) than in any other treatment in the first month. However, throughout the remaining 3 mo of incubation, total WS soil P concentrations generally decreased, but remained greater than the initial, and were similar among fertilizer treatments. Averaged over time, total Mehlich‐3 (M3) soil P concentrations in all three soils increased the most from the initial in the ST treatment (66.6, 71.3, and 74.5 mg kg–1, respectively), which did not differ from MAP and TSP. The comparable total WS‐P and M3‐P concentrations among fertilizers under flooded soil conditions further support struvite's agronomic potential as an alternative fertilizer P source.

Soybean growth and production as affected by struvite as a phosphorus source in eastern Arkansas

“…Similar aboveground P concentration and uptake between the two struvite materials (ECST and CPST) and the highly water‐soluble TSP contradicts the slow‐release characteristic of struvite previously reported (Rahman et al., 2014; Talboys et al., 2015). The struvite materials used in this study demonstrated a more rapid‐release characteristic, which has also been reported in plantless soil incubation experiments under moist‐ and flooded‐soil conditions (Anderson et al., 2021a, 2021c). In addition, soybean root exudation of carboxylate compounds could have also contributed to greater aboveground P concentration and uptake from the struvite materials, ECST and CPST, as struvite dissolution likely increased in the presence of organic acids exuded by plant roots (Tang et al., 2007; Cabeza et al., 2011; Antonini et al., 2012).…”

“…In a recent study, Omidire and Brye (2022) evaluated the effects of CPST in a wheat–soybean, double‐cropped production system in eastern Arkansas. Although ECST has been previously evaluated in other crops in the field, such as rice (Omidire et al., 2022a) and corn (Omidire et al., 2022b), in the greenhouse with corn and soybean (Ylagan et al., 2020), or in plant‐less soil incubation studies (Anderson et al., 2021a,b,c), field evaluations of ECST have not been previously conducted for soybean. Therefore, the objective of this field study to was evaluate soybean response to ECST, CPST, and other common fertilizer‐P sources (i.e., triple superphosphate, TSP; RP; diammonium phosphate, DAP; and monoammonium phosphate, MAP) in two consecutive growing seasons in a P‐deficient, silt‐loam soil in eastern Arkansas.…”

Total extractable phosphorus in flooded soil as affected by struvite and other fertilizer‐phosphorus sources

“…Diammonium phosphate and CPST were in pelletized form, whereas RP was in powdered form and ECST was in crystalline form. The T A B L E 1 Summary of initial soil properties (n = 3) among soils used in the soil incubation (adapted from Anderson et al, 2020aAnderson et al, , 2020b average diameters of the pelletized fertilizer-P sources were 2.9 (± 0.60) mm for DAP and 2.9 (± 0.57) mm for CPST (Anderson, 2020). Pelletized fertilizers and ECST were mechanically crushed and chemically characterized in powdered form to enable direct comparisons among fertilizer-P sources.…”

Wastewater‐recovered struvite evaluation as a fertilizer‐phosphorus source for corn in eastern Arkansas

“…Significance was judged at P < .05 for all analyses and least square means were reported. Similar to recent studies (Anderson, Brye, Greenlee, et al., 2021; Anderson et al., 2021a; Anderson et al., 2021b; Omidire, Brye, Roberts, et al., 2022; Ylagan et al., 2020), where similar fertilizer‐P treatments were used, least significant difference at the .05 level was used to separate means, when appropriate.…”