| Abstract: | The application of pig slurry as soil amendment is a common agronomic practice, but to avoid environmental hazards the doses are regulated. This article evaluates the N dynamic in two calcareous soils amended with legislated (170 kg N, D1) and high doses (1700 kg N, D2) of pig slurry and incubated for 300 days. Nitrification increased at the end of incubation (39–45 and 154–285 mg kg?1 in control, D1, and D2). Net N mineralization was similar in all soils (24–36 mg kg–1), but negative in D2 in soil 1 (–72 mg N kg?1). Soil type was an important factor for nitrification processes, with greater rates in the soil with high calcium carbonate content and with no effects on ammonification. Thus, legislated doses compared to control could be considered a wise practice. Conversely, overdoses displayed potential N processes influenced by the carbonate content and the salinity of the amended soil. |
