Slurry field management and ammonia emissions under M editerranean conditions

In S pain, farmers are interested in applying pig ( S us scrofa domesticus) slurry ( PS ) to their fields throughout the year. During the spring and summer months, ammonia ( NH sub(3)) volatilization may be high. We studied the potential range of NH sub(3) losses under a warm and a hot period of the year, using available field practices, and two strategies: PS directly incorporated into the soil, in spring ( I -spring); and PS applied by splash-plate, in summer time ( SP -summer), both to bare soil. Measurements were conducted, after PS application, using the micrometeorological mass balance integrated horizontal flux method. The cumulative NH sub(3)-N volatilization was 35% ( I -spring) and 60% ( SP -summer) of total ammonium nitrogen applied, and half of the total NH sub(3)-N losses happened by 17 h and 8 h, respectively, after application. Incorporation strategy was less effective in avoiding NH sub(3) losses than is described in the literature. This fact has important consequences for the implementation of NH sub(3) mitigation measures in M editerranean agricultural systems.