Grazing intensity and nitrogen fertilization effects on biomass and morphology of black oat roots in an integrated crop–livestock system

Grazing stimulates root and forage mass of perennial pastures, but few studies have addressed the effects grazing on annual pastures which are often grown in short periods within integrated crop–livestock systems (ICLS). In these N fertilization is a common practice to increase mass, its morphology unclear. field experiment, we evaluated how intensities (ungrazed, moderate, heavy grazing) rates (0, 75, 150 kg ha−1) affected morphological attributes oat (Avena strigosa Schreb.) roots accumulation ICLS Brazilian subtropics. Forage was each cycle were sampled 30-cm depth at end season 2 years. Heavy moderate reduced (p < 0.05) by 15%–37% compared ungrazed (4867 DM first year, characterized extended water deficit, second year from grazed similar > 0.05), averaging 4273 ha−1. increased both years, without differences between 75 ha−1 treatments. mainly diameter concentration. Increasing length it more expressive year. Nitrogen with or moderately an alternative as fine development uptake, when adverse climatic conditions can affect pasture growth.