The objective of the present research was to evaluate the effect of single sunflower crop on soil aggregation under different tillage systems. Four tillage systems were used: heavy disk harrow + leveling harrow (GA), leveling harrow (GN), sowing on straw (SP) without tillage (PD), in the autumn-winter, and chisel plow + leveling harrow in the spring-summer cultivation, except for PD treatment. The research was conducted under field conditions in Candido Mota and Pedrinhas Paulista, Sao Paulo State. Soybean was sowed in the spring-summer season and sunflower in the autumn-winter. The soil aggregates were evaluated before sowing and after sunflower harvest. The use of sunflower crop induced a better soil aggregation in both places, for all tillage systems.
physical properties; soil aggregation
