Initial growth of millet under bulk density levels in oxisol of the cerrado

The millet (Pennisetum americanum) is an annual cover crop in increasing use in the Cerrado region. Excessive use of agricultural machinery and inadequate management has caused losses in soil physical quality. Research has shown that besides being effective as ground cover, millet has shown ability to break through compacted layers. This study aimed to evaluate the growth and yield of millet plants subjected to levels of soil compaction. The experiment was carried out in a greenhouse using a completely randomized design. The treatments consisted of five levels of soil densities: 1.0, 1.2, 1.4, 1.6, 1.8 Mg m-3 with four replications. The recipients were built with PVC pipes of 200 mm diameter. The collection of the experiment was performed at 34 days after sowing and the variables analysed were: chlorophyll index, plant height, number of leaves and tillers, length and stem diameter, dry mass of leaves, stems and roots. All variables were subjected to analysis of variance and regression test at 0.05 probability. The bulk density of the Oxisol that provided the best development of millet plants varied between 1.0 to 1.4 Mg m-3.