Rice response as affected by various fertilizer‐P sources under contrasting irrigation methods

Alternative fertilizer‐phosphorus (P) sources created by recycling excess nutrients from waste sources, such as struvite (MgNH 4 PO 4 ·6H 2 O), require further research to determine their niche in agriculture and potential environmental implications. The objective of this study was to evaluate rice ( Oryza sativa ) response and greenhouse gas emissions intensity from a real‐wastewater‐derived and synthetic electrochemically precipitated struvite (ECST Real and ECST Syn , respectively) and a chemically precipitated struvite compared to monoammonium phosphate (MAP) and an unamended control grown under flood‐ and furrow‐irrigated conditions in a P‐deficient, silt‐loam soil in the greenhouse. A pure‐line rice variety was grown under delayed‐flood irrigation for ∼155 days in 2022, and a hybrid rice variety was grown for ∼170 days under simulated furrow‐irrigation in 2023. In both 2022 and 2023, aboveground dry matter did not differ among P‐fertilized rice treatments. Total plant P uptake in 2022 from MAP was 34.2 kg ha −1 , which was similar to all struvite fertilizer‐P sources. In 2023, aboveground P uptake from ECST Real was numerically greatest at 19.8 kg ha −1 and similar to ECST Syn and MAP at 18.6 and 17.9 kg ha −1 , respectively. The ECST Real and ECST Syn sources were similar among fertilizer‐P sources for all measured or calculated rice properties, except for methane emissions intensity in 2022 and aboveground tissue‐N concentration and uptake, total aboveground N uptake, and total plant P uptake in 2023. Results emphasized that the use of struvite could provide a viable fertilizer‐P source for both flood‐ and furrow‐irrigated rice production systems.