Reduction in Ammonia Volatilization from Pig Slurry Using Acidic Mechanisms

Pig slurry can be used as an alternative source for nutrients, particularly nitrogen (N), for plants. However, after applying the pig slurry to the soil, gaseous loss of N this nutrient may occur, mainly in the form of ammonia. Hence this study aimed to evaluate the loss of N by volatilization after the application of pig slurry with an acidified pH. Ammonia volatilization was evaluated using pig slurry, with its pH modified to 5.0 using four acids (sulfuric acid, citric acid, ascorbic acid, and acetic acid). Additionally, pig slurry with natural pH and a control were also used. The work was conducted in a greenhouse, and collectors were used to capture the volatilized ammonia in a static free semi-open chamber. The application of pig slurry with natural pH (7.19) resulted in 61% loss of ammonia, whereas acidification with ascorbic acid (pH 5.0) caused a loss of only 26%. The application of pig slurry with pH above 7.0 caused N loss, indicating that using acids to maintain a pH of 5.0-6.0 could be an alternative to reduce N loss by ammonia volatilization.