Effects of low-molecular-weight organic compounds on sulphur immobilization and re-mineralization and extraction of immobilized sulphur by hot-water and acid hydrolysis

Autor: Sophie Slezack-Deschaumes, P.C. Vong, Séverine Piutti, Armand Guckert, Emile Benizri
Rok vydání: 2010
Předmět:
Zdroj: European Journal of Soil Science. 61:287-297
ISSN: 1365-2389
1351-0754
DOI: 10.1111/j.1365-2389.2010.01228.x
Popis: We examined the effects of salicylate, glutamate and glucose on sulphur (S) immobilization and re-mineralization in three calcareous soils: from arable, fallow and forest managements. Each of the three substrates, at a single rate of carbon (1000 mg C kg -1 soil) was added to the three soils and then incubated with Na3/2 5 SO 4 plus Na 2 SO 4 for 1, 2, 6 or 12 weeks prior to analysis. The extraction of the immobilized S was performed with either hot water (HW-S) or 3 M hydrochloric acid (HCl-S). Except for the forest soil, the average amounts of immobilized S increased in the order control salicylate > glutamate = glucose, suggesting that the hot-water action was substrate dependent. In addition, the proportion of HW-S decreased with increasing incubation time, indicating that the youngest immobilized S was the most labile. Thus, hot water extracted more homogeneous S compounds than HCl. Sulphur immobilization induced by glutamate and glucose produced more recalcitrant S products (small quantities of 35 S re-mineralization) than that induced by salicylate. Glutamate tended to generate more recalcitrant S compounds than glucose. Hot-water extractable S was a valuable and rapid indicator of readily labile organic S. Consequent microbial S immobilization resulting from glucose or glutamate addition was followed by a small rate of re-mineralization of immobilized S.
Databáze: OpenAIRE
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