It has been found that the results of the land use and management techniques adopted for soils derived from Caiuá sandstone in the Northwest of Paraná are not always satisfactory in terms of crop yields. In this region, sandstone occurs in two forms: the Caiuá and Paranavaí Formations, with differences in soil particle size. We hypothesized that the water retention and availability for agricultural production is lower in the Caiuá soils, due to the higher proportion of coarse sand than in the Paranavaí soils. The aim of this work was to characterize the retention and availability of soil water in an integrated crop-livestock system and pineapple cultivation in Caiuá and Paranavaí soils in the Northwest of Paraná, Brazil. In 2010, two studies were conducted in four commercial farming areas (integrated crop - livestock and pineapple cultivation), with a sandy texture in the 0-40 cm layer. There was evidence that even under the best soil management the yields of soybean, pasture, and pineapple were very low in soils of Caiuá Formation. Disturbed and undisturbed soil samples were collected (layers 0-10, 11-20 and 21-40 cm) to characterize particle size (clay, silt, fine sand and coarse sand), organic carbon and water retention through water retention curves. In soil of the Caiuá Formation, the particle size was larger, pores had a greater diameter and water availability was lower than in Paranavaí soil. The risk of water stress was higher for Caiuá than for Paranavaí Formation soils.
Caiuá sandstone; clay; brachiaria grass; organic carbon; pore size distribution; water retention curve; livestock-crop integration
