Factors Affecting Organic Matter Analysis by Weight Loss On Ignition in Louisiana Coastal Wetland Soils.

Soil samples were collected from various Louisiana coastal wetland sites to study effect of salt content, sample sizes, heating temperature, and heating time on organic matter analysis by weight loss on ignition. The samples were treated with saline water at a ratio of 1:1 (v/v) at the concentrations of 5, 10, 20, and 40 ppt. Heating temperatures were varied from 400, 450, 500, 550, 600 and 650 ºC with heating times from 1, 2, 4, 8, and 16 hours. The sample sizes were 0.5, 1.0, and 2.0 g of dry samples. The results showed that the highest salt concentration (40 ppt) resulted in approximately 7-10 % less organic matter content as compared to 20 ppt. Organic matter increased significantly after temperature increased from 400 to 450 ºC (7-16 %). However, at temperature 550 ºC and higher, organic matter content was slightly increased about 0.5-1.5%. Increase of heating time and sample size were also slightly increased amount of organic matter content (1.0-1.5%).