Avalia??o da fertilidade dos solos de sistemas agroflorestais com cafeeiro (Coffea arabica L.) em Lavras-MG

摘要

The objective of this wark was to evaluat e the soil fertility in an agroforest system using coffee trees (Coffea arabica L - Mundo Novo), inga trees (Inga vera Wild) and grevillea trees (Grevillea robusta A Cunn) situated in Lavras, Minas Geris. A completely randomized experimental design with tree treatments and seven replicates was utilized. The treatments were : a) coffee trees in full sunshine; b) coffee trees mixed with inga trees and c) coffee trees mixed with grevillea trees. Tree spacings in the three systems were 4 x 1m for coffee, 8 m x 15 m for inga and 12 x 10 m for grevillea. With coffee and inga trees at 15 years of age and grevillea trees at 9 years of age, the following soil characteristics were evaluated; pH, potential acidity (H+Al), exchangeable aluminum (Al+3), exchangeable bases (Ca+2 and Mg+2), available potassium (K+), available phosphorus (P), sulfur (S), effective CEC(t), base sum (BS), base saturation (V) and organic matter (OM). The results were subjected to the analysis of variance and means compared by the Scott-Knott test. After data analysis, it was concluded that although there were differences among some studied parameters, the chemical characteristics of the soils under the three systems were not severely affected.