A mini soil bin was used to evaluate the effects of soil physical condition
s and the blades of cereal seeders (one straight and one curved) in the val
ue of the force that produces passive failure. The test was made at 12% hum
idity, 1.15 Mg/m(3) density 12cm depth and rake angle of 50 degrees. It is
concluded that the straight blade needs more putting force (6,03 N/cm(2)) t
han the curved one (4,72 N/cm(2)).