Grazing management in an integrated crop-livestock system: soybean development and grain yield

Resumo

Grazing livestock in integrated crop-livestock systems can cause impacts in the subsequent crop cycle.
Aiming to investigate how grazing could affect soybean, the 9th crop cycle of a pasture/soybean rotation was assessed.
Treatments were grazing intensities (10, 20, 30 and 40 cm of sward height) applied since 2001 in a mixed of oat and
annual ryegrass; and an additional no grazing area as control. Treatments were arranged in a completely randomized
block design with three replicates. Grazing affected soybean population and the mass of individual nodules (P<0.05),
while the number and mass of nodules per plant were similar (P>0.05). Soybean yield showed differences among
treatments, but no difference was found between grazed and non-grazed areas. Grazing intensities impact the coverage
and frequency of weeds (P>0.05). In conclusion, grazing intensity impacts different parameters of soybean yield and
development, but only the grazing intensity of 10 cm can jeopardize the succeeding soybean crop.