Effects of cattle dung and dung beetle activity on growth of beardless wheatgrass in British-Columbia

The nutrient value of fresh cattle dung for British Columbia rangeland plants was evaluated over two seasons in a pot experiment using depleted range soil and beardless wheatgrass, Agropyron spicatum var. inerme Heller. Dung treatments comprised fresh cattle feces (200 g) mixed manually with the soil, or worked in by the dung beetle Onthophagus nuchicornis (L.), or the same quantity of dung was placed intact on the soil without burial. There were also fertilizer treatments at 67 kg N/ha and 269 kg N/ha. Total incorporation of the fresh dung into the soil increased total crude protein production, potential seed production, and the vigor of the grass over 2 yr. Burial of an average 37% of the available dung by beetles caused a 38% increase in crude protein over that of the control. Crude protein production of grass treated with 67 kg N/ha was 95% higher than the control, while that treated with 269 kg N/ha was 144% higher. These rangelands have an impoverished native dung beetle fauna in comparison with some other climatically similar areas of the world. Efficient dung beetles should bury cattle dung more effectively during the growing season than do the present species. Establishment of such new species might provide an aid to nutrient recirculation and, through this, to maintenance of rangeland productivity.