Differential responses and mechanistic controls of soil phosphorus transformation in Eucalyptus plantations with N fertilization and introduced N2‐fixing tree species. Issue 6 (9th January 2023)

• Record Type: Journal Article
• Authors: Yao, Xianyu; Hui, Dafeng; Hou, Enqing; Xiong, Junfei; Xing, Shuo; Deng, Qi
• Is Part Of: New phytologist. Volume 237:Issue 6(2023)
• Page Start: 2039
• Page End: 2053
• Publication Date: 2023-01-09
• Subjects: arbuscular mycorrhiza fungi -- Eucalyptus plantation -- N2‐fixing trees -- phosphatase -- soil phosphorus fractions -- sustainable forestry; Botany -- Periodicals; 580
• DOI: 10.1111/nph.18673
• Languages: English
• ISSNs: 0028-646X

Abstract

Summary: Introducing N2 ‐fixing tree species into Eucalyptus plantations could replace nitrogen (N) fertilization to maintain high levels of N consumption and productivity. However, N enrichment may exacerbate phosphorus (P) limitation as Eucalyptus robusta Smith is extensively planted in P‐poor tropical and subtropical soils. We conducted a field experiment in a pure plantation of Eucalyptus urophylla × grandis to investigate the impacts of N fertilization and introduced an N2 ‐fixing tree of Dalbergia odorifera T. Chen on soil P transformation. Nitrogen fertilization significantly enhanced soil occluded P pool and reduced the other P pools due to acidification‐induced pH‐sensitive geochemical processes, lowering Eucalyptus leaf P concentration with higher N : P ratio. By contrast, introduced N2 ‐fixing tree species did not change soil pH, labile inorganic P pool, and Eucalyptus leaf N : P ratio, even enhanced organic P pools and reduced occluded P pool probably due to altering microbial community composition particularly stimulating arbuscular mycorrhiza fungal abundance. Our results revealed differential responses and mechanistic controls of soil P transformation in Eucalyptus plantations with N fertilization and introduced N2 ‐fixing tree species. The dissolution of occluded P pool along with organic P accumulation observed in the mixed plantations may represent a promising future to better manage soil P availability.