Soil nutrients were measured for 4 years in pastures under heavy, moderate, and light grazing intensities, that were seeded with one of three species (smooth bromegrass (Bromus inermis), meadow bromegrass (Bromus riparius) or winter triticale (X Triticosecale), to determine the effects of grazing intensity and forage species on soil N and P levels. After the third year of grazing, increasing grazing intensity increased nitrate, mineral N, and phosphorous levels in the soil, most likely because 2.4x more feces was deposited on heavily grazed pastures than on lightly grazed pastures. Forage species also affected soil N and P levels. Nitrate and ammonium-N concentrations were higher in pastures with bromegrasses than winter triticale; possibly because triticale had higher nutrient uptake than perennial grasses, or because more grazing days were required to graze bromegrasses to the appropriate grazing intensity, which resulted in 2x more urine and fecal inputs on these pastures than pastures with winter triticale. The input of feces and urine tended to have larger effects on soil nutrient levels than the forage species that was planted, The high nitrate levels under heavy grazing may be of environmental concern and methods to reduce these levels should be investigated.
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