Crescimento da parte aérea de plantas cultivadas em vaso, submetidas à irrigação subsuperficial e a diferentes graus de compactação de um Latossolo Vermelho-Escuro distrófico

Compaction is a process that can occur in soils managed inadequately, affecting crop growth and yield directly or indirectly. The shoot development was evaluated as a function of different degrees of subsoil compaction in soybean, corn, cotton, and Brachiaria brizantha plants grown in pots filled with soil material from a dystrophic Dark-Red Latosol, with water supply through subsurface irrigation. The experiment was carried out in screened greenhouse at the School of Agronomy and Veterinary Medicine of UFMT, in rigid PVC pots with 195 mm internal diameter in a completely randomized design in a 4 × 5 factorial scheme (four species and five soil densities - 1.0; 1.2; 1.4; and 1.5 Mg m-3). The water content in the soil/pot system was maintained above 60% of its maximum water retention capacity. At the end of the experiment, the plant height was measured and the plants cut at ground level; the leaf area estimated, and cotton, corn and soybean yield and the shoot dry matter evaluated. Soil densities above 1.4 Mg m-3 led to significant reduction in the development of shoot growth of cotton, corn, and soybean, while in Brachiaria brizantha plants the reduction was verified only at a density of 1.5 Mg m-3. Soybean presented the largest increment of the evaluated characteristics at a density of 1.2 Mg m-3. Brachiaria brizantha presented higher tolerance to compaction, whereas cotton plants were the most sensitive to effects of soil compaction. In general, the quadratic model adequately explained the growth of the studied plants as a function of soil compaction.