In recent times there has been a movement towards the use of non-conventional mineral and organic fertilisers. Advocates of these fertilisers believe that the overuse of synthetic fertilisers has resulted in the loss of natural soil fertility, reduction in food quality, pollution of ground waters and waterways, and acidification of soils (1). Very little rigorous research has been done to compare the different effects alternative fertilisers might have on crop productivity. This poster paper reports on these effects.

Methods

During 1990 a randomised block trial was conducted at Roseworthy to compare field performance of barley, Hordeum vulgare cv. Galleon, subjected to ten fertiliser treatments. The treatments, all of which were based on commercially available formulations, included synthetic, mineral and organic types compared with a control (nil fertiliser). The trial was sown at a rate of 140 seeds/m²and fertiliser application rates were based on the commercial recommendations. Various agronomic data were collected including plant and weed emergence, tiller numbers, grain yield, grain protein and grain test weight. In addition, cost effectiveness (relationship between grain yield relative to application cost) of each fertiliser was calculated. All data were subjected to an analysis of variance.

Results and discussion

The economic analysis demonstrated the superior cost effectiveness of Triple super, Biophosphate and Composite mix over the other fertilisers. All agronomic measurements, including grain yield and grain protein (Table 1) showed no significant difference irrespective of fertiliser type. This outcome was not surprising as the level of phosphorus in the soil at the beginning of the trial was quite high at 34 mg/kg. It is intended to continue this experiment over a number of years in order to take note of any long term advantages which are said to be associated with the use of mineral and organic fertilisers.

Table 1. Effects of fertiliser type on grain yield and grain protein of barley including the cost effectiveness of each fertiliser

* Values in rows not followed by the same letter differ significantly (P<0.05).
A = Pelletised chicken manure; B = Complete organic cropping fertiliser; C = Cropping Mix; D = Base product; E = Biophosphate; F Alkaphos extra; G = Triple super; H = Diammonium phosphate/sulphate of ammonia; I = Composite mix; J = Control.

Reference

8. Allenson, C.J. 1988. Acres Australia 1, 30-32.