Effect of urine volume on nitrate leaching in the northeast USA

To investigate how the urine volume (i.e. size of cow) affects how much NO3-N is leached from a urine deposition in the climatic conditions of the northeast USA, a field study using large drainage lysimeters to measure NO3-N leaching loss from synthetic urine applied in spring, summer and fall in 1-, 2-, and 3-l volumes to an orchardgrass (Dactyls glomerata L., c.v. 'Pennlate') sward was conducted from April 1997 to March 1999. The study site was located in central Pennsylvania on a Hagerstown silt loam soil (fine, mixed, mesic Typic Hapludalf). It was found that increasing urine volume increased the amount of urine N leached but had no significant effect on the apparent percent of urine N leached. The apparent percent of urine N leached was 25% averaged over all treatment times and volumes and was 21% for spring and summer applied urine and 32% for fall applied urine.