Performance of cover crop under the water deficit

The objective of this study was to evaluate the effect of drought on biomass of different cover crops. The experiment was conducted in a greenhouse at the experimental campus of the Federal University of Piauí (UFPI), on soil classified as Yellow Latosol dystrophic. The treatments were composed by five species of cover crops (Brachiaria brizantha cult. Xarés; Pennisetum glaucum cv. ADR 300; Brachiaria ruziziensis; Mucuna aterrima; Pennisetum. glaucum cv. ADR 7010) and four irrigation intervals levels (2, 4 6 and 8 days). Independent of the levels of water deficit, the highest biomass were obtained in species B. brizantha, B. ruziziensis, P. Glaucum cv. ADR 300 and ADR 7010. There was greater tolerance of M. aterrima levels of water deficit. The species of B. brizantha and B. ruziziensis accumulated 70% of the dry weight of tops of sheets, while P. glaucum cv. ADR 300 and ADR 7010 accumulated 60% of the stem. Even with reductions in biomass under water deficit conditions, the species B. brizantha and B. ruziziensis have potential for soil cover and P. glaucum residues as a source for the maintenance of soil organic matter.