Biases in the spatial estimation of pesticide loss to groundwater Yves Coquet, Dalila Hadjar, Jean-Marc Gilliot, Marie-Paule Charnay, Julien Moeys, Alexandre Dufour and Nicolas Beaudoin Agron. Sustain. Dev., 25 4 (2005) 465-472 DOI: 10.1051/agro:2005046