Compaction susceptibility of a yellow-red latossol subjected to different methods of weed control in a coffee field

Abstract

The objectives of this work were: a) to develop bearing capacity models for a Yellow Red Latossol cultivated with coffee, in function of the associated methods of weed control, pre-consolidation pressure and moisture; b) to identify, through these models, the weed control method most resistant and most susceptible to soil compaction between the rows and in the traffic lines. The experiment was set up at the EPAMIG Experimental Farm in Patrocínio, Minas Gerais state, in a coffee field (Coffea arabica L.). The methods of weed control were: between the rows: rotary tiller, disk harrow, were mower and no weeding (control). In each management system, 15 samples were collected at 0-3, 10-13 and 25-28 cm depths (totalizing 315 samples) to generate the bearing capacity model both between the lines and in the traffic lines, except for the control treatment, where sampling was done only between the lines. To obtain the bearing capacity models, the undisturbed soil samples with different moisture contents were subjected to uni-axial compaction. Between the rows, the rotary tiller and were mowers, at 0-3, 10-13 and 25-28 cm, promoted soil compaction, while the grade harrow promoted a relief of the soil’s mechanical resistance at the same depths. In the traffic line, the rotary tiller, at 0-3 cm, was the method of weed control most susceptible to compaction; at 10-13 cm the rotary tiller, disk harrow and were mower promoted soil compaction; at 25-28 cm a higher susceptibility was observed with the were mower.