Knowledge-based nitrogen fertilizer management strategies reduce ammonia volatilization in vegetable systems: Evidence from a meta-analysis and two field trials - Fen Zhang; Xiao Ma; Xiaopeng Gao; Hailing Cao; Fabo Liu; Yiming Tian; Tao Liang; Yan Wang; Yemisrach Zewdu Belay; Gabriel Schaaf; Xinping Chen; Xiaozhong Wang (Agriculture, Ecosystems & Environment, 2026)