Soil structure influences the hydraulic properties of the soil such as infiltration, runoff, evaporation and redistribution of water in the soil. Soil management practices have an influence on soil structure with consequences on the runoff of pesticides and leaching of both, pesticides and nitrates.
However, predictions of changes in the soil structure remain challenging due to its spatial and temporal variability. Roger-Estrade et al. (2009) propose an indicator of soil structure dynamics based on the proportion of compacted clods in the tilled layer to evaluate the effects of different crop management systems on soil structure and soil water transfer. Fawcett et al. (1994) reviewed the research on the impacts of conservational tillage on pesticide runoff in the USA from the years 1967-1991. According to Freier et al. (2015), glyphosate-containing herbicides were especially used in zero-tillage cropping systems (winter wheat and winter barley). On the contrary, Arondel and Girardin (2000) could show that ploughing was effective in decreasing both herbicide and fungicide use intensity, especially in high risk cropping systems.
There is no consensus regarding the effect of tillage on the transfer of nitrogen, several studies have shown equivalent losses between the two systems (Shipitalo et al., 2000; Oorts, 2006).
Therefore, the percentage of low/zero-tillage cropping systems could be used as indicator for herbicide use.