Preparo do solo, fertilização e controle de plantas daninhas em povoamentos de Pinus no sul do Brasil

Abstract

Silvicultural practices are essential for promoting significant gains in growth and productivity in Pinus forests. However, despite their widespread use in the management of this genus, responses to silvicultural practices are highly dependent on edaphoclimatic conditions. This study aimed to evaluate the effects of soil preparation, fertilization, and weed control on the survival, growth, and productivity of Pinus taeda and Pinus maximinoi in stands approximately seven years old in southern Brazil. Part of this research was organized and written in the form of a scientific article, with submission planned to an international forestry journal. The study was conducted at two sites: Otacílio Costa, with Pinus taeda established on a clayey Humic Cambisol, and Telêmaco Borba, with P. maximinoi cultivated on a clayey Red Latosol. The experiments were established in a randomized complete block design with a split-plot factorial arrangement, with soil preparation, fertilization, and weed control as experimental factors. Survival, height, and diameter at breast height (DBH) were periodically assessed over approximately seven years. Basal area and volume were calculated as productivity metrics. Statistical analyses were performed using linear mixed-effects models, with block considered as a random effect, followed by mean comparison tests to identify significant differences among treatments. The results demonstrate that responses to silvicultural practices were strongly dependent on site characteristics. In Otacílio Costa, weed control was the primary factor associated with increased survival, growth, and productivity of P. taeda, whereas soil preparation with subsoiling showed no effect and fertilization did not promote growth gains. In Telêmaco Borba, soil preparation with subsoiling was essential for survival and resulted in the greatest gains in growth and productivity of P. maximinoi, weed control also led to productivity gains over time, while fertilization contributed to early stand growth.