Impacts of timber harvest intensity and P fertilizer application on soil P fractions

Author(s)

Rocha, Jose Henrique T. ^{[1, 2]} ; Menegale, Marcella L. C. ^[3] ; Rodrigues, Marcos ^[4] ; Goncalves, Jose Leonardo de M. ^[2] ; Pavinato, Paulo S. ^[4] ; Foltran, Estela Couvre ^[2] ; Harrison, Robert ^[3] ; James, Jason N. ^[3]

Affiliation

^[1] FAEF, Agr & Forest Engn Coll, Garca, SP - Brazil

^[2] Univ Sao Paulo, Dept Forest Sci, Luiz de Queiroz Coll Agr, BR-13418900 Piracicaba, SP - Brazil

^[3] Univ Washington, Sch Environm & Forest Sci, Seattle, WA 98195 - USA

^[4] Univ Sao Paulo, Dept Soil Sci, Luiz de Queiroz Coll Agr, BR-13418900 Piracicaba, SP - Brazil

• Document type: Journal article
• Source: FOREST ECOLOGY AND MANAGEMENT; v. 437, p. 295-303, APR 1 2019.
• Web of Science Citations: 3

Abstract

Research has shown significant effects of timber harvest residue management on soil organic carbon (SOC), but less impact has been observed on the available P pool. The objectives of this study were: (1) to estimate the effects of different timber harvest intensities and P fertilization on soil labile P and P fate over time; and (2) to identify which soil P fractions supply P to Eucalyptus plantations cultivated in soils with low P availability. P fractions were assessed using Hedley's sequential extraction methodology, which corresponds to differing degrees of soil P lability. Three timber harvest intensities (stemwood only, whole tree and whole tree plus litter) and two levels of P fertilization (0 and 44 kg ha(-1) of P) were used. A total of 70% of total soil P was found in a non-labile form in the whole tree plus litter removal treatment, while in the whole tree treatment only 66% was found in this form. Removal of harvesting and litter residues resulted in a 40% reduction in the labile P fraction when compared to stemwood only harvested treatment even with fertilizer application. Acid phosphatase activity, which is crucial in mobilizing P for plant uptake, was 45% higher in soils that did not receive P fertilizer, but it did not resulted in higher concentration of labile P. Timber harvest intensity and P fertilizer application did not influence the soil total P concentration over 12 years of Eucalyptus cultivation. However, there was an increase in non-labile and inorganic P fractions and a reduction of labile and organic P fractions with increasing timber harvest intensity. The organic, moderately labile P fraction was the main source of P to the trees under low P availability conditions. Acid phosphatase and low molecular weight organic acid excretion seem to be important strategies of Eucalyptus species to improve P uptake. (AU)

• FAPESP's process: 14/15876-1 - Forest residue management and nutritional deficiency in two growth rotation of eucalypt
• Grantee: José Henrique Tertulino Rocha
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/08338-4 - IUFRO Eucalyptus 2018 - Managing eucalypt plantations under global changes
• Grantee: José Henrique Tertulino Rocha
• Support Opportunities: Research Grants - Meeting - Abroad