Short-term nitrogen balance in urine-treated areas of pasture on a yellow earth in the subhumid tropics of Queensland.
1984
Vallis I. | Gardner C.J.
The recovery of nitrogen from cattle urine applied to a legume-grass pasture on a yellow earth in north-eastern Queensland was measured over periods of 8-28 d in March, July-August and October-November. Urea labelled with 15N was used as a tracer for urine nitrogen. The weather in all three experiments was dry; cumulative evaporation from an open pan was 6-25 times rainfall. The total apparent loss of 15N from the soil-plant system was 18 percent after 8 d in March, 32 percent after 28 d in July-August, and 16 percent after 28 d in October-November. Losses of 15N were most rapid during the first 1-2 d after application. Most of the recovered 15N was in the soil. Further, most of the 15N in the soil was present as mineral nitrogen, mostly exchangeable ammonium. Wetting the soil or removal of herbage and litter resulted in poorer recovery.
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