With the objective of evaluate the root growth capacity in the compacted soil layer, four vegetal species of the cover crops (amaranth, pearl millet ADR500, finger millet and kenaf) were cultivated in columns of PVC with increasing levels of subsurface compaction (soil bulk densities: 1.18; 1.34; 1.51 and 1.60 Mg m-3). The experiment was carried out in a greenhouse conditions, using a Dusky Red Latosol. The subsurface compacted layer was restrictive to the roots growth of the studied species, causing the root concentrating to the surface. Pearl millet ADR500 and the amaranth were the species that had detached in the production of dry matter weight and developed itself in the compacted layers and below of them. Pearl of millet ADR500 presented the biggest root length density in all layers. Finger millet and the amaranth had similar behavior in relation to the shoot length root. Finger millet and kenaf had presented minor dry matter weight of root in relation to the other species. The kenaf presented minors values of dry matter, but it was not affected by the presence of compacted layers.
soil resistance; root length density; growth root
