Temporal Sediment Particle Size Distribution and Organic Carbon Release with Low and High Kinetic Energy Wetting In Interrill Erosion.

Temporal sediment particle size distribution and organic carbon release with low and high kinetic energy in interrill erosion Abstract Sediment particle size distributions seem to depend on factors such as the erosive agent (rainfall or runoff), flow (sheet or rill), rainfall rates, slope and soil type. Because so many interactions are acting especially in interrill erosion, how temporal sediment size distribution changes and how these changes can affect organic carbon releases still remain unknown. The objective of this study was to evaluate the effect of low (LKE) and high kinetic energy (HKE) on runoff rate, temporal particle size distribution, sediment delivery rate and organic carbon movement in interrill erosion from two different soils under CT and NT. It was found that with HKE, temporal particle size distributions in the sediment changed from a low to a high percentage of the smallest particles, but this behavior was not observed with LKE in the Maury soil. In the Calloway soil only NT shows this comportment. Total organic carbon content (TOC) in different particle sizes in the sediment was analyzed by a repeated measure in time model considering energy, tillage system, soil type and time like main factors. TOC in different particles released from both soils was generally not a time process, according to the third order interaction (energy*tillage*soil*time). TOC released with particles was not changing in time but remained almost constant during the rainfall. The soil by tillage interaction was significant for all particles sizes but these between 0.053 and 0.105 mm, indicating that tillage had an important effect on TOC release. This behavior should be considered to evaluate OC sequestration under NT.