Micromorphology of pores and water erosion in Inceptisol soil after application of pig slurry

The application of pig slurry (PS) to soil is known to change its chemical and physical properties. However, little is known about the alterations that PS causes in pore morphology and water erosion. This research evaluated the influence of PS on the morphology of the pores in the surface layer of the soil and on water erosion in an Inceptisol subjected to simulated rainfall. The soil was cultivated with black oats and the treatments (doses) 0, 50, 100 and 200 m3 ha-1 of PS were applied to the crop residue. The experimental design was completely randomized. Six simulated rainfall lasting 60 minutes and planned constant intensity of 65 mm h-1 were applied to the treatments. Undisturbed soil samples were collected in the 0-0.05 m layer, 24 h before and 24 h after the first, third and sixth rainfall events. Image analysis was performed, determining the percentage of macropores and mesopores, number, diameter and shape of the pores, using the micro morphometry technique. PS doses of 100 and 200 m3 ha-1, combined with simulated rainfall, favored surface sealing and pore rearrangement. There was an increase in the number of small and rounded pores, without interconnection between them, with a consequent increase in water erosion until the moment of stabilization of the superficial crust. Keywords: micro morphometry, organic fertilizer, porometry.