ABSTRACT
The design parameters and field performance of a liquid waste injection machine for shallow sub-soil placement are described. Field experiments were conducted to determine the effects on pasture growth of
sub-soil injected and surface broadcast liquid cow and pig wastes and animal blood at nutrient rates of 25 kg N/ha, and blood at 317 kg N/ha, and equivalent broadcast dry inorganic fertilizer. The injector was found to adequately dispose of liquid waste in the sub-soil at 75 mm depth. No sustainable responses in pasture growth occurred when 25 kg N/ha of wastes or dry fertilizer were injected or surface applied. A significant increase
in pasture growth was obtained when blood or dry fertilizer at 317 kg N/ha was applied. Pasture growth responses continued over longer periods when blood was injected at this rate than when it was surface applied, suggesting that better nutrient conservation occurred when wastes were placed in the sub-soil.
