The effects of 12 years of cover crops and sediment collection on the SOC stocks (Mg∙ha−1
∙layer–1
∙year−1 or
layer thickness × 100 m × 100 m) retained on the lower slope landscape position are shown in Table 3. The
calculations assume that most or all of the SOC remains attached to the sediment and 50% to 70% of SOC rich
sediment is retained in the border and filter strips. Any SOC dissolved in runoff water and not attached to sediment
would be delivered to the stream. The mass of the SOC dissolved in the runoff water is not known. However,
the mass of the dissolved SOC is probably rather small when compared to the amount of SOC attached to
sediment particles. This dissolved SOC will most likely be quickly returned from the water to the atmosphere as
either methane gas or carbon dioxide. The sediment rich in SOC is deposited in the border strips and filter strip
located on the lower slope and between the plots and stream. The SOC stored on the lower slope includes both
the SOC stored or retained on the cover crop plots and the sediment retained in the border and filter strips.