241-5 Nitrogen and Carbon Dynamics Within a Maintained Bermudagrass-White Clover Lawn.
A 3-year study evaluated the effects of white clover inclusion within a hybrid bermudagrass lawn. Supplemental N (0, 0.5, 1, 2, 4, and 8 g N m-2) was applied monthly, April to August, in order to evaluate the effects of supplemental N upon biomass composition, N fixation, N transfer, and soil carbon.
Mixed grass plus clover swards yielded higher clipping biomass than grass-alone swards, which was evidence of enhanced bermudagrass growth due to biological N fixation. Likewise, grass biomass of mixed swards was increased relative to that of grass-alone swards at supplemental N rates ≤ 10 g N m-2 year-1 but was decreased at higher supplemental N rates. N fixation was estimated to be 6.6 g m-2 year-1 during the 3-year study, with an apparent increase in fixation as years progressed. Results indicate that N fixation was suppressed at the lower and upper extremes of supplemental N rates. N transfer to the associated bermudagrass sward was estimated to be 24% during the latter two years of the study. Soil carbon levels were similar among all treatments.