Dynamics of phosphatase activities in a cork oak litter (Quercus suber L.) following sewage sludge application |
| |
Authors: | Sylvie Nèble Virgile Calvert Jean Le Petit Stéven Criquet |
| |
Institution: | Institut Méditerranéen d’Ecologie et de Paléoécologie, UMR CNRS 6116, Laboratoire de Microbiologie, Service 452, Faculté des Sciences et Techniques de Saint-Jérôme, 13397 Marseille cedex 20, France |
| |
Abstract: | As part of a study of the processes involved in litter biodegradation following sewage sludge (SS) addition, the variations over 14 months of phosphatase activities in a cork oak litter (Quercus suber L.) were investigated. A field experimental design was carried out using the litter-bag method on both a fertilized plot receiving SS applications (twice ) and a control plot. Acid (APH) and alkaline (BPH) phosphatases were measured, along with several biotic and abiotic variables potentially involved in the regulation of these enzymes. These included moisture, temperature, pH, water-extractable inorganic P (PW), culturable heterotrophic bacteria and fungi. Sludge addition had significant effects on all the variables measured. Indeed, sludge increased significantly BPH activities, available PW, microbial densities (i.e. bacteria and fungi) and pH in the fertilized plot. In contrast, APH activities decreased significantly following sludge addition. As a consequence, the BPH/APH ratio increased markedly and immediately in the fertilized plot, but only after the 1st amendment. Following the 1st preconditioning SS amendment, the 2nd fertilization had fewer effects on biological variables, because of summer dryness. The different properties examined varied significantly with incubation time, and most were significantly related to the seasonal patterns of litter moisture in this Mediterranean forest ecosystem. Hence, sewage sludge application modified the intensity of microbial responses to environmental factors, but biological patterns regulating P turn-over were maintained. |
| |
Keywords: | Alkaline and acid phosphatases Available P Bacteria Fungi Organic amendments |
本文献已被 ScienceDirect 等数据库收录! |
|