Studies about reduced tillage in soil cultivated with roots and tubers are rare and controversial. This study aimed to assess and compare the sweet potato tuberous roots yield in an alfisol type soil managed with conventional tillage (plowing followed by leveling and making mounds) and reduced tillage with straw on the soil surface (cultivated only along the rows). The experimental design was in randomized blocks in split-plot scheme. The principal plots corresponded to conventional tillage (with mounds) and reduced tillage, and the subplots to four collect periods: 90, 120, 150 and 180 days after planting. The characteristics evaluated were: total and commercial yields, numbers of total and commercial tuberous roots, and commercial tuberous roots individual fresh mass. Sweet potato crop had total and commercial tuberous roots yields around 68 and 75% higher in conventional tillage, respectively, than in reduced tillage. This response was caused by the high numbers of total and commercial roots in soil under conventional tillage. There was no difference between the soil management on tuberous roots individual fresh mass. As conclusion, the conventional tillage is better to the sweet potato crop.
Ipomoea batatas; soil conservation; reduced tillage; tuberous root
