Ethylene production and decomposition in soils

Abstract

Six soils differing in texture and use were investigated for their ability to produce and decompose ethylene. In addition, changes in methane and CO2 concentrations were monitored. The effects of organic amendments and different water tensions were studied, and a method using low concentrations of acetylene as an inhibitor of ethylene degradation was tested. Possible reduction of acetylene to ethylene was identified by the use of CO or NH4 +-N, of which the latter turned out to be the more reliable method. This reduction only occurred in a grassland soil. Under aerobic soil conditions, gross ethylene production rates of up to 4.7pmol g–1 h–1 could be measured. Highest ethylene production and lowest ethylene decomposition was detected in a spruce forest soil. Fine textured soils produced more ethylene than coarse textured soils. Amended soils produced more ethylene at –100kPa and –5kPa than at 0kPa water tension. Ethylene decomposition was most effective in soils from deciduous woodlands and reached rates of up to 137pmol g–1 h–1. Parallels between ethylene and methane decomposition were observed. The addition of 5mgg–1 glucose and 1mgg–1 methionine not only promoted ethylene production but also inhibited ethylene decomposition.