This work had as objective evaluate the penetration depth of cut disks (flat, corrugated and wavy) of seeder in different vegetable coverings (corn, sorghum, black oats, triticale and grass) and applied vertical loads (750, 1500, 2250 and 3000 N). The work was developed at University of Agronomic Sciences - UNESP of Botucatu in a soil classified like NITOSSOLO VERMELHO distroferrico. The experimental design used was in blocks at random with factorial outline (3 coulter disks and 4 vertical loads) and 4 repetitions. The results showed that for all vegetable covering, as larger is the vertical load applied adult as larger is the penetration depth of the coulter disks. The wavy disk cut obtained the smallest values of penetration depth in relation to the others. This happened due to smaller cut pressure in the straw. The largest values of penetration depth of the cut disks were obtained for the covering with straw of nabica following by the triticale, black oats, corn and sorghum. The seeder should be regulated with minimum load of seed and fertilizer so that happen the cash cuts of the straw during the sowing process.
