Enzymatic stoichiometry in tropical soil under pure and mixed plantations of eucalyptus with N-2-fixing trees

Autor(es)

de Araujo Pereira, Arthur Prudencio ; Ferreira Araujo, Ademir Sergio ; Santana, Maiele Cintra ; Viana Lima, Antonio Yan ; Vieira Prudencio de Araujo, Victor Lucas ; Verma, Jay Prakash ; Bran Nogueira Cardoso, Elke Jurandy

• Tipo de documento: Artigo Científico
• Fonte: CIENTIA AGRICOL; v. 80, p. 7-pg., 2023-01-01.

Resumo

Soil enzymes play a fundamental role in nutrient cycling in forest systems. The stoichiometry of C, N, and P-acquiring enzymes has been used to indicate nutrient limitation in the soil. However, the enzymatic stoichiometry remains poorly understood in pure and mixed eucalypt plantations. Thus, this study aims to assess the activity of enzymes in the soil to address the hypothesis that the introduction of N-2-fixing trees could influence the enzymatic stoichiometry on C, N, and P cycling. The activity of beta-glucosidase (BG), urease (U), and acid phosphatase (AP) was assessed in soil (0-20 cm depth) of pure Eucalyptus grandis without (E) and with N fertilization (E+N), and a mixed system with E. grandis and Acacia mangium (E+A), and a pure A. mangium (A) plantation at 27 and 39 months after planting. The activities of BG/U, BG/AP, and U/AP were used to calculate the enzyme C/N, C/P, and N/P ratios, respectively. Rates of N-acquiring enzymes were higher in E and E+N, while soil microorganisms invested in P-acquiring enzymes in A and E+A. The vector length and angle demonstrated that C demand by microorganisms does not change in relation to N and P, regardless of the treatment. However, N demand decreased in relation to P in A and E+A (mainly at 27 months). Our results suggest that enzymes activity in pure eucalypt systems is limited for their soil-litter nutrient contents. At the same time while acacia and mixed plantation seem to invest in P-acquiring enzymes to improve biological N-2 fixation promoted by diazotrophic bacteria associated to acacia. (AU)

• Processo FAPESP: 17/16610-3 - Plantações intercaladas de Eucalyptus grandis e Acacia mangium: o microbioma do ciclo do nitrogênio na interface solo e serapilheira
• Beneficiário: Arthur Prudêncio de Araujo Pereira
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 10/16623-9 - Intensificação ecológica de plantações de eucaliptos pela associação com espécies leguminosas arbóreas fixadoras de nitrogênio
• Beneficiário: José Leonardo de Moraes Gonçalves
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 16/01636-4 - O metagenoma de florestas mistas de Eucalyptus urograndis: Diversidade taxonômica e funcional do microbioma do solo associada à ciclagem do nitrogênio
• Beneficiário: Arthur Prudêncio de Araujo Pereira
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 16/18944-3 - Mudanças climáticas e eficiência energética na agricultura: um enfoque em estresse hídrico, manejo orgânico e biologia do solo
• Beneficiário: Elke Jurandy Bran Nogueira Cardoso
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático