Urine patches from cattle in pastures represent high local applications of nitrogen (N), of which a substantial part is lost to the environment by emissions of NOx, N2O and NH4 and leached as organic N (DON), NO3 and NH4. Cattle stocking schedules provide an important tool for farmers in controlling the amount and distribution of urine patches, and potentially mitigating losses. In a lysimeter study we applied artificial urine (400 kg N ha-1) with 15N labeled urea (1.480% excess 15N) to undisturbed soil cores (Ĝ =18 cm, h = 60 cm) taken from two pastures on sandy soils. Simultaneously, a replicated field study was initiated on one of the pastures, receiving a similar urine application with 0.493% excess 15N. In both studies, 3 treatments were implemented: urine application in the beginning of September, October and November 2004. At the end of the leaching season (October-March) leaching, soil storage and crop uptake averaged approximately 20%, 40% and 30% of the 15N recovery, respectively. The total N-recovery from the urine patches was >90%. Initially, mineral nitrogen (NO3) accounted for the majority of the soil storage (>80%), especially for the November treatment, but in March 60% of the total 15N recovered in the soil was in the form of organic N. Both N2O emissions and N leaching were significantly different in the respective treatments. Therefore, stocking schedules can be used to mitigate various types of nitrogenous emissions from urine patches.
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