ABSTRATC
The adoption of reduced tillage and no-tillage is growing fast in many crops, but studies in soil cultivated with roots and tubers are rare and show controversial results. Thus, this study aimed to assess the impact of tillage systems on physical properties of an Alfissol type as well as the sweet potato tuberous roots yield and root shape cultivated in that soil. The experiment was conducted in randomized blocks design, in split-plot scheme. The plots consisted of the treatments: tillage with moldboard plow and disking (PAG), tillage with moldboard plow, disking and making mounds (PAG + L), making mounds without previous soil mobilization (Leira), reduced tillage (PR) and reduced tillage with straw on the soil surface (PRCP). The subplots consisted of 4 collect periods: 90; 120; 150 and 180 days after planting of the sweet potato crop. Making mounds activity (Leira and PAG + L), opposite to reduced tillage, promoted lower values of soil bulk density, soil resistance to penetration and soil microporosity, higher scores of total soil porosity and soil macroporosity, besides the highest commercial tuberous roots yields and higher dry mass percentage. It was concluded that soil managements influence expressively the soil physical properties and, for making mounds, the activities of moldboard plow and disking are unnecessary, since Leira and PAG + L present similar values in the physical properties studied and in commercial tuberous roots yield.
Key words
Ipomoea batatas; soil bulk density; soil resistance; native vegetation; yield
