THE EFFECT OF ACETYLENE ON N-TRANSFORMATIONS IN AN ACID OAK-BEECH SOIL

The effectiveness of acetylene (C2H2) as inhibitor of nitrification was studied in relation to the decomposition of C2H2. This was done by examining the effects of single and multiple additions of different C2H2 concentrations (10, 100, 1000 Pa) on mineral N and NO3--N production in samples of the organic (FH) and upper mineral (Ah) layer of an acid oak-beech forest soil. The decomposition of C2H2 was much faster in Ah samples than in FH samples. A single addition of 10 Pa C2H2 was not sufficient for complete inhibition of nitrification in the Ah samples. Nitrification was blocked completely by all other C2H2 treatments in both FH and Ah samples. Addition of C2H2 decreased net mineral N production in Ah samples but not in FH samples. Addition of carboxymethyl-cellulose and chitin to Ah soil had no affect on the rate of decomposition of C2H2. Chitin had a negative effect on net NO3--N production.