Monday, November 13, 2006

Soil Active Carbon Assesment as Affected by Soil Properties and Testing Conditions.

Jianli Ping, Thomas Morris, Dawn Pettinelli, and Robert Durgy. Univ of Connecticut, 1376 Storrs Rd; Unit 4067, Plant Science, Storrs, CT 06269

Soil active C is that portion of C in the soil that can serve as a sensitive indicator of soil quality associated with management practices. A recently proposed test for active carbon involves the oxidation of C by potassium permanganate. The test has been shown to provide a simple and effective assessment of active C that is related to changes in management of the soil. However, the test does not measure the total C in the soil, and the reliability of the test can be affected by soil properties and laboratory procedures.  This study aims to quantify how soil properties and small differences in laboratory procedures affect test results for active C. Our results indicate that when soil C content is high, the amount of soil per ml of K-permanganate should be reduced. Additionally, the testing procedures should be completed in a well-controlled sequence to ensure that each soil sample has similar time of contact with the regent. The test for active carbon should achieve more reliable results and should be a more reliable indicator of soil quality if users of the test follow our small modifications.