EFFECT OF FORM AND RATE OF PIG MANURE ON THE GROWTH, NUTRIENT-UPTAKE, AND YIELD OF BARLEY (CV GALLEON)

The effect of 2 rates of piggery waste on the growth, nutrient uptake and yield of barley (cv. Galleon) were compared with a fertiliser mixture of superphosphate and urea in the field. The piggery waste was either applied as a slurry (16 kL/ha or 32 kL/ha) or as a solid (0.5 t/ha or 1.5 t/ha). Both the fertiliser mix and the slurry significantly increased the growth and yield of barley while the dried manure failed to improve growth and yield. The effects of treatments on the nutrient concentration in plant tissue throughout the year were small and mainly not significant, while the increases in nitrogen and phosphorus content in the crop reflected the changes in dry matter production. The grain yield responses to fertiliser and to the slurry appeared due to an increase in nitrogen available to the crop rather than to the increase in the supply of phosphorus or other nutrients. The higher rate of the slurry reduced the boron concentration and increased the sodium concentration in the tissue but the concentrations of these elements were not great enough to affect plant growth adversely. However, the increase in sodium concentration following application of the slurry suggests that there may be some risk in the build up of sodium in the soil with the continued use of high rates of slurry, particularly in drier environments. The experiment indicates that the slurry was as effective as fertiliser in eliciting a response and was more effective, in the short term, than the dried form of manure.