Effects of broiler shed litter on the establishment and growth of perennial pasture on infertile acid podzolic soils

Abstract

The effect of applying broiler shed litter, at rates of 2-32 t ha-1, on the establishment and growth of perennial pasture was compared with that of a molybdate/superphosphate/potash fertilizer on two infertile podzolic soils on Tasman Peninsula, Tasmania. Broiler litter had little effect on the establishment of the sown species although white clover establishment was depressed at the highest rate. Herbage yield in the first spring was increased from 1.5-8.0 t DM ha-1 as the rate of litter, applied before sowing, increased from 2-32 t ha-1. Residual effects of the 32 t ha-1 dressing doubled herbage production in the second year in comparison with the 2 t ha-1 litter dressing but residual effects of the 4 and 8 t ha-1 dressings were small. In both years, yields from plots initially receiving inorganic fertilizer or 2 t ha-1 of litter were similar. In the second year the proportion of sown grass increased, and the proportion of weeds decreased, as the initial rate of litter increased from 4-32 t ha-1. The propotion of both white and subterranean clover was also reduced, but only at the highest rate of litter. Irrespective of the initial treatments, a maintenance dressing of litter at 2 t ha-1 at the beginning of the second year slightly increased the proportion of sown grass but halved the legume component in comparison with a maintenance dressing of 250 kg ha-1 of superphosphate. The data indicate that on these infertile soils litter at 2 t ha-1 can replace the inorganic fertilizer recommended for pasture establishment but that superphosphate rather than litter should be applied in the second year to encourage clover growth, and thus build up soil fertility.