In their abstract, Larsen and Noack say they wanted to take a deeper look to see if “concerns that more simplified cropland with lower crop diversity, less noncrop habitat, and larger fields results in increased use of pesticides due to a lack of natural pest control and more homogeneous crop resources.”
The study gathered data on crop production and insecticide use from more than 100,000 field-level observations from Kern County, CA, and ran from 2005 to 2013. It considered how factors like crop diversity, field size, and cropland affect insecticide use in normal agricultural practice.
The results? Here’s what Larsen and Noack say in their abstract:
“Overall, we find that higher crop diversity does reduce insecticide use, but the relationship is strongly influenced by the differences in crop types between diverse and less diverse landscapes. Further, we find insecticide use increases with increasing field size.
“The effect of cropland extent is distance-dependent, with nearby cropland decreasing insecticide use, whereas cropland further away increases insecticide use. This refined spatial perspective provides unique understanding of how different components of landscape simplification influence insecticide use over space and for different crops.
“Our results indicate that neither the traditionally conceived ‘simplified’ nor ‘complex’ agricultural landscape is most beneficial to reducing insecticide inputs; reality is far more complex.”
American Vegetable Grower® reached out to Larsen, Assistant Professor, Agricultural and Landscape Ecology, to learn more about the study.