Changes on soil chemical properties in no tillage system that received pig slurry applications for long time

This study was based on two experiments carried out in Western Santa Catarina, Brazil, to evaluate
the effect of pig slurry and N fertilizer on soil nutrient availability in no-till corn on a Red Latosol (Oxisol). Soil samples were collected after the last corn cropping (season 2003/04), at dephts of zero to 5, 5 to 10 and 10 to 20cm, and were submited to chemical analyses. Treatments consisted of zero, 40 and 115m3/ha of pig slurry application
on the soil, combinated with zero, 60 and 120kg/ha N. Surface application of pig slurry in no-tillage system increased the nutrient availability mainly at zero to 5cm depth. Utilization of pig slurry for three or four years increased the contents of organic matter, cation exchange capacity and extractable phosphorus. The intensity of observed alterations in the layers were proportional to the application rates. Treatments had no effect on the exchangeable K, Ca, Mg, Al and pH. It was observed that phosphorus in a clayey Latosol has very low mobility.