Water content, organic carbon and dry bulk density in flooded sediments

Several basic properties of pond bottom soil are shown to be related. a rel ation that enable to evaluate pond bottom soil characteristics through the determination of one parameter (e.g. soil moisture). In addition, these rel ationships give some insight into the: properties of flooded sediments. Unl ike terrestrial soils. made of gas, liquid and solid phases, flooded sedime nts are made practically of only two phases. liquid and solid. Since all vo ids are filled with water, it is possible to evaluate soil porosity and bul k density, directly from the moisture content of the soil, a property easil y determined. The correlation between bulk density and organic matter was t asted in six different systems (n = 868), including rivers and fish pond se diments in Israel. fish pond sediments in Alabama, USA, and Abbassa, Egypt, lake sediments in New Zealand, alpine lake sediments in Colorado, USA, and sea floor sediments from the Northwest African continental slope. Sediment bulk density was inversely related to the organic carbon concentration. Th e regression for all the data points was. B ulk density (g/cm(3))= 1.776 - 0.363 Log(e) OC (R-2 = 0.70) where OC is the organic carbon concentration (mg/g). The relationship betwe en sediment moisture, bulk density and organic carbon described here can be used as a simple means to estimate the organic content and bulk density of flooded mineral soils by a simple determination of a sediment water conten t. (C) 2001 Elsevier Science B.V. All rights reserved.