P-31 NMR spectroscopy and structural models of soil organic phosphorus under Eucalyptus

Author(s)

Rinaldi, Lais Chierici Bernardes ^[1] ; Aleixo, Seldon ^[2] ; da Silva, Erika Caitano ^[1] ; Gama-Rodrigues, Antonio Carlos ^[1] ; Gama-Rodrigues, Emanuela Forestieri ^[1] ; de Moraes Goncalves, Jose Leonardo ^[3] ; Rocha, Jose Henrique Tertulino ^[4] ; Schripsema, Jan ^[2]

Affiliation

^[1] Univ Estadual Norte Fluminense Darcy Ribeiro UENF, Lab Solos, BR-28013602 Campos Dos Goytacazes, RJ - Brazil

^[2] Univ Estadual Norte Fluminense, Grp Metabol, Lab Ciencias Quim, BR-28013602 Campos Dos Goytacazes, RJ - Brazil

^[3] Univ Sao Paulo, Dept Ciencias Florestais, ESALQ, BR-13418900 Piracicaba, SP - Brazil

^[4] Fac Agron & Engn Florestal FAEF, BR-17408899 Garca, SP - Brazil

• Document type: Journal article
• Source: NUTRIENT CYCLING IN AGROECOSYSTEMS; v. 120, n. 1, p. 83-97, MAY 2021.
• Web of Science Citations: 0

Abstract

Organic phosphorus (P-o) plays an important role in tropical forest nutrition on strongly-weathered soils. However, of its role in Eucalyptus nutrition little is known. For this purpose, soil P forms were determined by NaOH-Na(2)EDTA extraction and P-31 nuclear magnetic resonance spectroscopy (P-31 NMR) at 10 sites of Eucalyptus plantations in Brazil. The objectives were (1) to determine the amounts and forms of soil P-o; (2) to build a structural model of the soil P cycle to provide quantitative estimates of the transformation processes of soil P. Soil P was found to consist of large amounts of Monoesters-P (on average 43.7 mg kg(-1)) followed by Diesters-P in the form of DNA (on average 4.2 mg kg(-1)), as well as containing high reserves of P-i species (on average 101.6 mg kg(-1) of the ortho-P; 2.7 mg kg(-1) of the pyrophosphate). Thestructural model indicated that the P cycle is regulated by clay, soil organic carbon, total P and pH. High total P-o concentrations (on average 48 mg kg(-1)) reveal a high potential of P supply to Eucalyptus trees, in which Diester-P (DNA) would be the main source P for the available P pool. The close interconnection between ortho-P, pyrophosphate, DNA and Monoester-P compounds provides evidence of a strong influence of soil biological activity on the distribution and accumulation of these P compounds and therefore on the availability of P. Thus, these results are relevant to establish soil fertility management strategies for low-fertilizer input Eucalyptus systems in soils with low fertility. (AU)

• FAPESP's process: 10/16623-9 - Ecological intensification of eucalyptus plantations by association of nitrogen fixing leguminous tree species
• Grantee: José Leonardo de Moraes Gonçalves
• Support Opportunities: Research Projects - Thematic Grants