ETHYLENE ACCUMULATION IN SOIL IN RESPONSE TO ORGANIC AMENDMENTS

One of the major factors affecting ethylene (C2H4) accumulation in soil is the availability of organic substrates. Various organic compounds were screened for their stimulatory effect on C2H4 accumulation in soil. Since L-methionine (L-met), a sole precursor of C2H4 synthesis in plants, is also an excellent precursor for microbial biosynthesis of C2H4, all the compounds tested were added on a C-equivalent basis with respect to 1 g L-met kg-1 soil. Incubation was carried out under ambient conditions (24 ± 3 °C) for 14 d and the soil was maintained at field capacity (-33 kPa.). Among the 63 compounds tested, the majority of amino acids, organic acids, carbohydrates, proteins, alcohols, and MET analogs promoted C2H4 generation to a greater degree than did the unamended soil.