Abstract
The effects of cattle dung deposition on nitrogen flow were investigated in bahiagrass pasture rotationally grazed by Holstein heifers. ND (no dung was deposited), JD (a dung pat was artificially deposited in June) and AD (a dung pat was artificially deposited in August) treatments were applied to the pasture. Measurements were done for a year after the dung deposition for each treatment. Results were as follows. 1. Dung nitrogen disappearance was slower in AD treatment than in JD treatment, mainly caused by the lower rainfall in Autumn. 2. Annual nitrogen uptake and retention by plant and grazed herbage nitrogen by heifers in JD and in AD treatments were not significantly different from those in ND treatment, while effects of dung deposition appeared in the seasonal nitrogen uptake and retention and grazed herbage nitrogen. 3. Litter nitrogen productions in the dung covered and the surrounding areas of JD and AD treatments were significantly higher than those in ND treatment. The results were discussed in relation to the characteristics of bahiagrass pasture.
