Técnica de meia-lua e coberturas vegetais no estabelecimento de espécies arbóreas da Mata Atlântica

Abstract

Given the degradation of the Atlantic Forest, restoration actions are required in combination with techniques that mitigate water limitation, such as half-moon planting basins and mulching, especially under climate change scenarios. In this context, this study evaluated the effects of the half-moon planting technique and soil mulching with castor bean residues (Ricinus communis L.) and grass straw (Urochloa decumbens (Stapf) R.D. Webster) on plant survival and growth, as well as herbivory incidence and soil temperature and moisture, using seedlings of six native Atlantic Forest species: aroeira (Astronium urundeuva (M. Allemão) Engl.), jenipapo (Genipa americana L.), jaracatiá (Jacaratia spinosa (Aubl.) A. DC.), pau-formiga (Triplaris americana L.), saboneteira (Sapindus saponaria L.), and tamboril (Enterolobium contortisiliquum (Vell.) Morong). The experiment was conducted at the Parque Natural Municipal de Glória de Dourados (Municipal Natural Park of Glória de Dourados), Mato Grosso do Sul, Brazil, in a completely randomized design with nine treatments: T1 — half moon; T2 — crowning; T3 — half-moon + straw mulching; T4 — crowning + straw mulching; T5 — half-moon + castor bean mulching; T6 — crowning + castor bean mulching; T7 — half moon + straw mulching + castor bean mulching; T8 — crowning + straw mulching + castor bean mulching; and T9 — control. Survival and growth were assessed quarterly, herbivory incidence every two weeks, and soil temperature and moisture monthly. Statistical analyses were performed using R software, applying Kaplan–Meier survival curves and the log-rank test for survival; ANOVA (5%) and Tukey’s test for relative growth rate (RGR); and the Kruskal Wallis test (5%), followed by Dunn–Bonferroni, for herbivory incidence, soil temperature, and moisture. There was a significant difference in survival among species (p < 0.0001), with lower rates in the half-moon with castor bean mulch (T5), attributed to the effects resulting from fermentation and microbial activity observed in the castor bean mulch. Differences were also found in RGR for height and diameter (p < 0.05), with higher values in the half-moon + castor bean mulching treatment (T5) and greater growth in E. contortisiliquum and J. spinosa. Herbivory incidence varied among species (p < 0.05), with the highest occurrence in G. americana and in T8. Soil temperature differed among treatments at 12:00 PM (p < 0.05), with thermal attenuation observed in mulched treatments. Soil moisture also varied among treatments (p < 0.05) and was higher in treatments combining the half-moon technique with mulching. The half-moon technique with castor bean mulch was not efficient due to low seedling survival and high management demand, with straw mulch being a more recommended alternative.