Biblioteca do Café
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/1
Navegar
2 resultados
Resultados da Pesquisa
Item Carbon balance in organic conilon coffee intercropped with tree species and banana(Sociedade de Investigações Florestais, 2020) Silva, Diego Mathias Natal da; Heitor, Letícia Célia; Candido, Aildosn de Oliveira; Moraes, Bárbara Santos Antônio de; Souza, Gustavo Soares de; Araújo, João Batista Silva; Mendonça, Eduardo de SáOver the last decade, conilon coffee (Coffea canephora) in consortium with wood trees has been established to improve environmental conditions. Little is known about how individual wood trees and banana affect soil quality when intercropped with conilon coffee. The objective of the present study was to evaluate the impacts of intercropping organic conilon coffee with different wood tree species and banana on C balance. Five cultivation systems including conilon coffee monoculture and intercropped with Inga edulis, Gliricidia sepium, BRS Japira banana (Musa sp.), or Bactris gasipaes were studied in a randomized complete block design, with four replicates at the south of Espírito Santo State, Brazil. A primary forest fragment adjacent to the experiment was also evaluated for comparison with the consortium. Samples of topsoil (0 to 10 cm) were collected in 2016 to evaluate the total organic C and total N. Soil temperature and moisture at 0 to 5 cm depth and the CO2 emission were measured monthly over one year. The species planted with the conilon coffee promoted a 5.52% decrease in the soil temperature and a 17% increase in the soil moisture content. They also promoted an increase in annual C balance, especially intercropped with Gliricidia and Inga (4.70 and 3.56 Mg ha-1, respectively), with a substantial increase in the soil total organic C and total N in both systems.Item Humic substances and its distribution in coffee crop under cover crops and weed control methods(Escola Superior de Agricultura "Luiz de Queiroz", 2016-07) Martins, Bruno Henrique; Araujo-Junior, Cezar Francisco; Miyazawa, Mario; Vieira, Karen MayaraHumic substances (HS) comprise the passive element in soil organic matter (SOM), and represent one of the soil carbon pools which may be altered by different cover crops and weed control methods. This study aimed to assess HS distribution and characteristics in an experimental coffee crop area subjected to cover crops and cultural, mechanical, and chemical weed control. The study was carried out at Londrina, in the state of Paraná, southern Brazil (23°21’30” S; 51°10’17” W). In 2008, seven weed control/cover crops were established in a randomized block design between two coffee rows as the main-plot factor per plot and soil sam- pling depths (0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm) as a split-plot. HS were extracted through alkaline and acid solutions and analyzed by chromic acid wet oxidation and UV-Vis spec- troscopy. Chemical attributes presented variations in the topsoil between the field conditions analyzed. Cover crop cutting and coffee tree pruning residues left on the soil surface may have interfered in nutrient cycling and the humification process. Data showed that humic substances comprised about 50 % of SOM. Although different cover crops and weed control methods did not alter humic and fulvic acid carbon content, a possible incidence of condensed aromatic structures at depth increments in fulvic acids was observed, leading to an average decrease of 53 % in the E4 /E6 ratio. Humin carbon content increased 25 % in the topsoil, particularly under crop weed-control methods, probably due to high incorporation of recalcitrant structures from coffee tree pruning residues and cover crops.