The intensive use of machines and agricultural equipments in the northeastearn São Paulo State has contributed to increase the areas with compaction problems, probably due to the absence of a well-defined operation chronogram or of models capable of predicting the soil support capacity. This study was conducted in Guariba (SP), with the objective of evaluating the spatial variability of the penetration resistance, soil moisture, and bulk density of a Oxisol (rhodic Eutrustox) under sugar-cane cultivation. The soils were sampled at […]

High phosphate adsorption in oxidic tropical soils changes the charge balance on the surface of particles and can increase dispersion. Consequently, it can affect pore size distribution, aggregate stability and susceptibility to compaction. In order to measure the effect of phosphate sorption on compression curves and consistence limits, a Dark-Red Latosol (LE) (very fine, allitic, isothermic Typic Hapludox) and a Cambisol (C) (very fine, isothermic Oxic Distropept) were sampled at 0-3 and 27-30 cm depth, at Campos da Mantiqueira, Minas […]

In a trial carried out at Santa Barbara, MG, Brazil, the influence of plant population on throughfall, crop evapotranspiration (ETc) and soil moisture regime of Eucalyptus grandis stands was evaluated. Plant population varied from 500 to 5000 trees ha-1. Soil moisture was measured down to a depth of 285 cm by a neutron probe, every 15 days. Rain water interception increased linearly with increasing plant population, whereas ETc was not significantly influenced. Soil moisture level tended to increase as plant population decreased. During […]

Face the planosols (Albaqualf) importance to the agricultural activities in the South Region of the State of Rio Grande do Sul, Brazil, the effect of chiselling on physical parameters of this soil was studied. Experiments were carried out at the Agricultural Machines Experimental Area of EMBRAPA – CPACT, in Capão do Leão, RS, November, 1994. It was analysed the effect of chiselling at three operating speeds (4.76; 3.63 and 2.58 km h-1), in two levels of soil moisture content (119.6 […]