Effectiveness of undersown crops and strip tillage at reducing erosion and pesticide transfer in maize crop
(2022) Land Use and Water Quality: Agriculture and the Environment — Location: Maastricht, the Netherlands (12.September.2022)
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PosterLuWQ2022-Effectivenessofundersowncropsandstriptillageatreducingerosionandpesticidetransferinmaizecrops.pdf
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- Authors
Clement, Timothée 
- Abstract
- Soils of the European loess belt are intensively used for industrial cropping and are known to be prone to surface crusting and erosion. Subsequent runoff and sediment transfer from cropland result in various off-site impacts such as muddy floods and the contamination of surface waters by sediments, nutrients, and pesticides. As a result, there is increasing pressure on the agricultural community to adopt alternative cropping practices to alleviate their environmental impacts. To this end, as part of the Intell’eau project, we assessed the effectiveness of two conservation practices at mitigating water, sediment, and pesticide flows by means of erosion plots under natural rainfall during the 2021 cropping season in forage maize. A control treatment, representing conventional maize farming practices, was compared to 1) maize undersown crops (red fescue or white clover) sown in the inter-row at the same time as the maize and 2) strip-tillage, which consists in preparing the seedbed by tine-tilling the maize row only, leaving the inter-row surface undisturbed. All treatments were implemented in triplicate. Results from the undersown crop plots showed no statistically significant difference in seasonal runoff, soil and pesticide (sulcotrione) losses compared to the control practice (bare inter-row). Most soil and pesticide losses occurred in June, when the undersown crops and maize are still poorly developed (< 5% total vegetation cover). Total seasonal runoff, soil and sulcotrione losses were 15.7±4.4 mm, 13.6±7.1 t/ha and 0.19±0.05 g/ha for undersown crop plots, and 18.6±2.6 mm, 11.5±4.7 t/ha and 0.15±0.08 g/ha for control plots. Nevertheless, during the extreme rainfall events of 13-15 July 2021 (119 mm in three days at the trial site), the undersown crops reduced runoff by 83% (1 mm, versus 6 mm for control plot) and soil losses by 90% (0.03 t/ha, versus 0.3 t/ha for control). When strip tillage was performed after a winter cover crop (mustard), a statistically significant difference (p = 0.1) between strip-till and the conventional practice (rotary harrow) was observed regarding seasonal runoff (-45%), soil (-70%) and pesticide (-66%) losses. When strip tillage was performed on soil left bare during winter, no differences were observed in terms of runoff, soil and pesticide losses. On the latter site, a particularly important development of rills was observed in the inter-row in the strip-till plots. Yield differences between conventional and conservation practices were always below 10%, and none were statistically significant. Further investigations (additional years and locations) are needed to better evaluate the effectiveness of these two techniques. In particular, the follow-up of the undersown crop in time must be considered, since benefits are expected from a well-established cover during the winter period, as well as from the supply of organic matter to the soil upon destruction before spring, with likely improvements in soil structure.
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Citations
Clement, T., Bielders, C., Degré, A., Manssens, G., Foucart, G., Pigeon, O., Blondel, A., & Huyghebaert, B. (2022). Effectiveness of undersown crops and strip tillage at reducing erosion and pesticide transfer in maize crop. Land Use and Water Quality: Agriculture and the Environment, Maastricht, the Netherlands. https://hdl.handle.net/2078.5/241012