Cover crops growth under water deficit

Abstract

One of the challenges to be overcome in no till deploying in tropical regions is the production of straw in the offseason, a period commonly with low water availability. To help in the choice of species to be used as cover crop in dry winter regions, the aim of this work was to evaluate the effect of soil water potential on growth of black oat (Avena strigosa Sckreb), pearl millet (Pennisetum glaucum (L.) R. Brown), grain sorghum (Sorghum bicolor L. Moench.) e guinea sorghum (Sorghum bicolor subespécie bicolor raça guinea). Pearl millet is a good option to be cropped during offseason by show high yield potencial, even been more sensitive to water deficit. Grain sorghum and guinea sorghum are also good options, particularly by showed abundant root system, which possibly gives them a certain tolerance to low water availability conditions. The black oat, even with high tolerance to water stress (tolerance conferred by highest percentage of fine roots), seems to be much affected by higher temperatures, common to these regions.