Carbon nitrogen ratio

Initial carbon-nitrogen ratios (by mass) hetween 35 and 50 are optimum for aerobic composting. At lower ratios ammonia is given off Biological activity is also impeded at lower ratios. At higher ratios nitrogen maybe a limiting nutrient. 

A number of substituted triazines are used as herbicides, and their biodegradation has been discussed in Chapter 10, Part 1. Treatment of soil contaminated with atrazine (2-chloro-4-(ethylamino)-6-isopropylamino-l,3,5-triazine) illustrated a number of significant features. Although the soil that was used had the potential for degradation, a laboratory experiment with Pseudomonas sp. strain ADP that had an established potential for atrazine degradation revealed important limitations. There was a substantial decline in the numbers of Pseudomonas sp. strain ADP and only limited mineralization. Supplementation with citrate or succinate increased the survival of the strain, and successful mineralization was dependent on the preservation of a carbon/nitrogen ratio >10 (Silva et al. 2004). The last would apply generally to substrates with a low C/N ratio such as triazines. 

Shake flask studies were carried out at 39°C in 125-ml Erlenmeyer flasks containing 40 ml of medium (180 rpm, 2.5 cm dia cycle). The carbon nitrogen ratio was varied by increasing or decreasing the diammonium tartrate supply, and Mn(II) added as specified. A spore inoculum was used (0.5 to 1.0 10 spores/ml final concentration). 

Lin, C. Y., and Lay, C. H. 2004a. Carbon/nitrogen-ratio effect on fermentative hydrogen production by mixed microflora. Int. J. Hydrogen Energy, 29,41-45. 

Roman, M. R. (1980). Tidal resuspension in Buzzards Bay, Massachusetts. 3. Seasonal cycles of nitrogen and carbon Nitrogen ratios in the seston and zooplankton. Estuar. Coastal Mar. Sci. 11, 9—16. 

Agitation rate Carbon/Nitrogen ratio Magnesium level Sulfur level Nitrogen source Dissolved oxygen level... 

Composting was the channel by which many of the plant nutrients were prepared for application to the soil. Many of the waste plant materials were weedy with wide carbon-nitrogen ratios, and the oriental farmers learned early that such materials can be utilized... 

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