The diffusion of agricultural innovations is rarely rapid. As a result, adoption decisions over time are very likely to be influenced by changes in generic factors such as the price of complementary inputs and environmental conditions. Despite this, the vast majority of studies aiming to explain innovation adoption are limited to cross-sectional data and analysis techniques that cannot accommodate time-dependent variables. This study departs from these attempts by using a duration analysis technique to investigate the significance of time-dependent economic and environmental variables, along with cross-sectional variables such as technology-specific perceptions, on the adoption of soil-conserving cropping practices by grain growers in southern Australia over the period 1983-2003. Of particular interest is the possible trade-off faced by farmers where adoption of no-tillage cropping technology can lead to greater herbicide reliance and subsequently unsustainable weed management due to high risks of herbicide resistance. Results show that factors affecting the cost-effectiveness of herbicides are important in the adoption of the erosion-reducing cropping systems. Several factors relating to the availability and use of technical information are also shown to be influential. The duration analysis approach allowed changes in time-dependent variables, including the fall in the price of the herbicide glyphosate, to be identified as determinants of the timing of no-till adoption. (c) 2005 Elsevier Inc. All rights reserved.