TRANSFORMATION OF SUGARS WHEN RYE HEMICELLULOSE LABELLED WITH ¹⁴C DECOMPOSES IN SOIL

Abstract

Summary Incubation of soil with 14C hemicellulose from rye straw for 448 days resulted in the evolution of about 70 per cent of the substrate as CO2. The two major sugar components of the hemicellulose, xylose (50 per cent) and arabinose (5 per cent), were almost completely decomposed. After 56 days only 5 per cent of the xylose remained and after 448 days only 1‐2 per cent. Similar results were obtained for soil derived from either granitic or basic igneous parent material. Almost 4 per cent of the hemicellulose was transformed to glucose and I per cent to mannose during the first 14 days of incubation. Fine grinding of 14C rye straw increased the extent of its decomposition on incubation but after 448 days 20 per cent of both its xylose and arabinose remained. It is suggested that the isolated hemicellulose is decomposed faster because it has been made water soluble.

The nature and dynamics of soil organic matter: Plant inputs, microbial transformations, and organic matter stabilization

“…The production of these compounds can be used to estimate microbial growth, but 398 may also accumulate in the microbial products, especially in extracellular slimes-biofilms (Redmile-Gordon et al, 2014). They also and react with humic substances (Cheshire et al, 1974). The role of polysaccharides in aggregation is well-established (Acton et al, 1963;Six et al, 2002a, Fry, 2015.…”

Evolution of Concepts of Environmental Natural Nonliving Organic Matter

“…In other soil incubation studies Cheshire et al (1974Cheshire et al ( , 1979 found that some sugars in straw in labeled plant material decomposed rapidly, but others decomposed relatively slowly, and about 15% of these remained after fi ve years. There was little indication that xylose or cellulose was synthesized by soil microorganisms.…”

Relationship between neutral sugars and the degree of humification in Andisols

“…According to Cheshire et al (1974), Murayama (1977Murayama ( , 1980Murayama ( , 1984a and Tanaka (1990), the content of mannose was very low in the neutral sugar composition of plant materials such as wheat straw, rice straw, plant residue from paddy soil, and roots of Japanese pampas grass. Therefore mannose can be considered to be a sugar of microbial origin in soil.…”