e-mail: els.wynen@elspl.com.au website www.elspl.com.au

The availability of the new technology of minimum or zero tillage and direct drill in Australia since the 1970s has led to the adoption of this technology at different rates in different states. This led to a radical increase in expenditure on herbicides in Australia in general, and in Western Australia in particular.

It is often claimed that the technology stemmed soil deterioration in cropping areas. However, wheat yield trends in Australia over the last 40 years are low as compared to those of its competitors. Short rotations are seen as part of the problem. Though these are brought about partly by financial factors such as relative product prices, the availability of a technology which slows down soil erosion is likely to influence rotation decisions. Expansion into areas which would have suffered unacceptable levels of soil deterioration with previous weed management techniques are seen to have occurred with the help of direct drill.

Several private and public costs and benefits were pointed out. The dichotomy between opinions of some farmers and researchers on the one hand (herbicide resistance), and those of many other researchers and extension personnel on the other hand (often with a brief in the area of farm productivity and soil and water conservation) could well be related to differences in costs and benefits to the different players.

Some institutional arrangements are relevant to the adoption of minimum tillage/ direct drill. These include:

• research funding bodies, which are mainly commodity-based. Off-farm problems, even those due to the production of a particular commodity, are often not considered relevant to the funding body's charter;
• policies regarding input costs:

In Australia, cost of pesticides reflect the market price, without an explicit allowance for non-market costs such as environmental costs.

In summary, the adoption of minimum tillage / direct drill seems still to be on the increase in Australia, probably partly due to the efforts of government departments connected with agricultural production and soil and water conservation and other institutional arrangements. This is the case even though the advantages of direct drill per se are not clear, especially since at least part of the benefits claimed could well be due to stubble retention. Warnings by some of the scientific community about long-term problems with direct drill (for example herbicide resistance) and environmental considerations generally seem to receive little attention in Australia.

The paper contains information on:

• the scale of adoption of the technology of minimum tillage / direct drill;
• figures on pesticide use in Australia over the last 20 years shown under different categories; and
• consequences of the adoption of the new technology in terms of private and public costs and benefits.