Agronomic practices such as fertilizer application or seed rates have been known to affect rice pests and damage, but the evidence is often blurred in studies on pest management decisions and invisible in studies on pesticide lock-in. Combined agronomic practices and pesticide use may create technological lock-in, occurring when the combination has accumulated advantages over time which encourages its continued use, even if better options are available. We present results from a survey among farmers (N = 400) from five provinces in Cambodia. We asked about field-level, agronomic practices and applied a regression analysis to determine whether these practices affect pesticide application. Farmers from the selected provinces produce rice intensively, particularly those in provinces in the Mekong Delta where a percentage of farmers would aim for three crops per year.

Cambodian farmers in the five sampled provinces rely on pesticides for pest controlwith an average of 2–5 applications each for herbicide and insecticide, and 1–6 applications of fungicide per season. Farmers from the Mekong Delta, particularly Prey Veng Province, made more pesticide applications. Interestingly, of nine agronomic practices tested, six were found to significantly correlate with no applications as in organic management recommendations, as well as misuse of pesticides. Varied combinations of agronomic practices including seed rate, crop establishment method, seed treatment, cultivating larger landholdings, irrigation through gravity irrigation system, and number of fertilizer applications predicted herbicide, insecticide and fungicide application. Interactions varied across wet and dry season. Pesticide use makes sense to farmers given a specific combination of agronomic practices. Therefore we argue that field-level agronomic practices contribute to pesticide lock-in as much as wider innovation system conditions such as trade and regulation of pesticides.

These findings imply that addressing the pesticide lock-in to facilitate a shift to more sustainable practices, such as Integrated Pest Management, should not only aim at broader innovation systems or industry level changes. There are adjustments and fine-tuning of agronomic practices that also need to be made to wean farmers from pesticide reliance.