Mineralization and humification of Dactylis glomerata litter in field experiment excluding macroarthropods

Decomposition rate of Dactylis glomerata was compared in two types of field mesocosms - (O-open) accessible for macroarthropods active on the grassland soil surface, or not accessible (C-closed) for them. Content of total carbon and nitrogen, as well as carbon incorporated in humus compounds was determined in the litter exposed in litter bags and inside poor in organic matter sandy substratum underlying the litter. Studies were repeated in two experiments, each lasting about a year. At the end of experiments 51-61% of the initial amount of carbon, introduced in the litter was mineralized, 13-19,7% was transformed into humus acids. Mineralization rate was more intense in C mesocosms, higher amount of humus was recorded in mesocosms accessible for macroarthropds (by 2,3 and 14,6% in autumn, respectively in both experiments). This newly formed humus was easily decomposable, part of it, particularly fulvic acids, were mineralized during winter