The Effect of Crop Rotation on Pesticide Leaching in a Regional Pesticide Risk Assessment

Abstract

New modeling approaches that include the use of GIS are under development in order to allow a more realistic assessment of environmental contamination by pesticides. This paper reports a regional GIS-based risk assessment using a software tool able to simulate complex and real crop rotations at the regional scale. A single pesticide leaching assessment has been done. The mean annual pesticide concentration in leachate has been analyzed using both stochastic and deterministic approaches. The outputs of these simulations were mapped over the sampling locations of the regional pesticide monitoring program, demonstrating that GIS-based risk assessment can be used to establish new monitoring programs. A multiple pesticide leaching assessment for analyzing the risk related to pest control strategies in six different maize-based rotations has been carried out. Additive toxic units approach has been used. Crop rotation allows to mediate the risk related to pesticide use because forces the use of different compounds with different fate and toxicology properties.

Investigating Potential Water Quality Impacts of Fungicides Used to Combat Soybean Rust in Indiana

“…Balderacchi et al (2008) has shown that crop rotation mitigates the risk from pesticide contamination by 48-74% depending upon the number of crops involved in the rotation. Therefore, for a cornsoybean rotation (currently the dominant crop rotation within Indiana), the fungicide concentrations in runoff and in the bottom of the root zone soil water from small agriculturally dominated watersheds would be approximately 50% of the modeled values if other model inputs remained the same.…”

Preferential Flow in a Pedological Perspective

“…For example, Balderacchi et al (2008) used the network of pedotransfer functions (pedotransfer system) developed by for the dual-permeability model MACRO to support a catchment and regional-scale risk assessment tool for pesticide leaching to groundwater in northern Italy. the EU Water Framework Directive and the 'Thematic Strategy for Sustainable Use of Pesticides') have prompted the development of spatial modeling tools to support pesticide risk assessment and management that can account for all significant loss pathways, including preferential flow.…”

Comments on pesticide risk assessment by the revision of Directive EU 91/414

“…Eco-ethical principles may be used to derive the acceptable concentrations and the acceptable risk in a landscape ecological context. It is welcome that pesticide effects will be assessed in a pest control strategy context (Balderacchi et al 2008) because they never reach the whole share of the market (Brown et al 2007). Options will be identified.…”