Ratios of C, N and P in Soil Water Direct Microbial Immobilisation-Mineralization and N Availability in Nutrient Amended Sandy Soils in Southwestern Australia

• Published in: Agriculture, ecosystems & environment Vol. 127; no. 1; p. 93
• Main Authors: Qiu, Song, McComb, Arthur J, Bell, Richard W
• Format: Journal Article
• Language: English
• Published: 01.08.2008
• ISSN: 0167-8809

Ratios of C, N and P in soil water direct microbial immobilisation-mineralisation and N availability in nutrient amended sandy soils in southwestern Australia are examined. The response of microbial activity to the soil amendments depends on amendment type and original nutrient conditions. The availability of carbon and nutrients plays an important role in sustaining microbial activity, and the highest response is triggered by the amendment combining C, N and P. The data suggest that net-N-mineralisation is mainly a microbial response to non-carbon amendments; while the net-N-immobilisation is the microbial response to the increased C availability. Such microbial behaviour appears to be due to microbial physiological response to soil nutrient conditions to sustain growth, and essentially the soil conditions can be expressed as the C/N ratio.