Fertilization of P. taeda L. on an acidic oxisol in southern Brazil: growth, litter accumulation, and root exploration

Authors: CONSALTER, R - Universidade Federal Do Parana; MOTTA, A - Universidade Federal Do Parana; BARBOSA, J - Uninga University Center; VEZZANI, F - Universidade Federal Do Parana; RUBILAR, R - University Of Concepcion; Prior, Stephen - Steve; NISGOSKI, S - Universidade Federal Do Parana; BASSACO, M - Western Paraná State University

Submitted to: European Journal of Forest Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/27/2021
Publication Date: 6/2/2021
Citation: Consalter, R., Motta, A.C., Barbosa, J.Z., Vezzani, F.M., Rubilar, R.A., Prior, S.A., Nisgoski, S., Bassaco, M.V. 2021. Fertilization of P. taeda L. on an acidic oxisol in southern Brazil: growth, litter accumulation, and root exploration. European Journal of Forest Research. 140:1095-1112. https://doi.org/10.1007/s10342-021-01390-z.
DOI: https://doi.org/10.1007/s10342-021-01390-z

Interpretive Summary: Pine forests can show low yield, high litter, and high root exploration of litter on very low fertility latosols in southern Brazil. The influence of nutrient and lime additions on these measures were studied in a nutrient experiment with seven treatments: 1) complete (N, P, K, B, Zn, Cu, Mo, and lime as a Ca and Mg source); 2) NPK omission; 3) micronutrient omission; 4) K omission; 5) Zn omission; 6) lime omission; and 7) control. Treatments were applied when the stand was five and seven years old, followed by harvest at twelve years. Macronutrients (N and P) enhanced commercial volume, while lime and Zn additions reduced yield. Fertilization and lime increased number of trunks and wood commercial volume with larger diameter and commercial value, and also increased litter accumulation (especially without K) where enhanced root exploration was twice as much as the control. Litter amount and extensive root growth within litter helped manage soil fertility that influenced yield and timber classification on this poor acid soil in southern Brazil.

Technical Abstract: On very low fertility latosols in southern Brazil, Pinus taeda L. forests can exhibit low yield, high litter accumulation, and high root exploration of litter layers. Under such conditions, the influence of nutrient and lime additions on growth, yield, timber classification, litter accumulation, and root distribution within litter was tested. In 2008, a nutrient omission experiment with seven treatments (one complete, five omission, and one control) was implemented: 1) complete (N, P, K, B, Zn, Cu, Mo, and lime as a Ca and Mg source); 2) NPK omission; 3) micronutrient omission; 4) K omission; 5) Zn omission; 6) lime omission; and 7) control. Treatments were applied when the stand was five and seven years old, followed by harvest at twelve years. Treatments influenced tree height and diameter at breast height. Macronutrients (N and P) enhanced commercial volume (60 to 122 m3 ha-1), while lime and Zn applications reduced yield. Fertilization and lime increased number of trunks and wood commercial volume with larger diameter and commercial value. Fertilization and lime also increased litter accumulation, especially under K omission where enhanced root exploration was twice that of the control (i.e., root mass, length/area, and length/litter mass). An extensive root system with root masses of ~ 3 to 8 ton ha-1 and lengths of ~100 to 300 km ha-1 was found within litter. Litter amount and root growth within the litter fraction appeared to help manage soil fertility that influenced yield and timber classification on this poor acidic latosol in southern Brazil.