The relation between water use and pesticides – Some remarks on the influence of integrated farming practices

Agriculture is the main user of the world’s water resources. Due to increasing concern on water quality and quantity, there is a growing interest to use the scarce water resources in the most efficient way to feed the growing world population. By employing a meta-analysis, this paper shows that pesticide use in combination with other improved production technologies have tripled agricultural water use efficiency (WUE) in the last 30 years. Recently, the European Union banned several active substances, among these more than 20 pesticides formerly used in crop growing. By doing so the progress in WUE has been put into question. This paper argues that a sudden reduction of pesticides by 50 % would lead to a need for more than 55 million hectares of additional arable land and for more than 158 km3 of additional water. Furthermore, in such a case the global irrigated area would have to be increased by 4 %. As most studies on the worldwide potential of additional arable land show, this land does not exist. Therefore, there are strong arguments to invest even further into new water saving technologies including pesticides. Specific research is needed to clarify which countries would be affected most by a sudden restriction or even ban of pesticides.