Growth of potato under deep tillage and succession with grass types

Potato in Brazil is often cultivated after corn (Zea mays) using the conventional tillage system, which achieve about 20 cm depth, not deep enough to remove physical impairments below the prepared layer. Thus, a deep tillage system associated to succession with grass types is postulated as an alternative to promote the adequate development of the potato crop. This study, with the cultivar Atlantic, aimed to compare the conventional tillage (PC) used in potato, in succession to corn, to a deep tillage system (PP), in succession with three different grass types (corn, Brachiaria brizantha cv. Marandu and Panicum maximum cv. Tanzânia) on the growth dynamics of potato. The dry matter production (MS, t/ha) of the aboveground part of the grasses was different in descending order: Tanzânia PP (26.56) > Marandu PP (19.94) > Corn PP (5.57) = Corn PC (5.72). With respect to potato development, Corn PP (5.56 and 85.51) was higher than Corn PC (4.34 and 64.83 g/plant MS) for the production of roots and leaves respectively, no statistical difference being found among the other treatments. For the production of stalks, Corn PC (5.53 g/plant MS) was the lowest and for the production of tubers, Marandu PP and Corn PP (152.16 and 149.01 g/plant MS) were higher than Corn PC (115.73 g/plant MS). In summary, the deep tillage system provided better development of potato and the effects varied depending on the grass type used for succession.