Cropping systems alter plant volatile emissions in the field through soil legacy effects

Abstract Crops emit a variety of volatile organic compounds (VOCs) that serve as attractants or repellents for pests and their natural enemies. Crop rotations, off-farm chemical inputs, mechanical cultural tactics – collectively called cropping systems alter soil nutrients, moisture content, microbial communities, all which have the potential to crop VOC emissions. Soil legacy effects diversified been shown enhance emissions in greenhouse studies, but how they influence under field conditions remains virtually unknown. To determine effect on plant field, air samples were collected from headspace wheat ( Triticum aestivum L. Judee) grown simplified wheat-fallow rotations wheat-cover where cover crops terminated by grazing cattle. Across two growing seasons, rotation with fallow emitted greater amounts Z -3-hexenyl acetate β-ocimene, key stem sawfly Cephus cinctus Norton), major pest wheat. While overall blends relatively similar among system during first season, varied substantially second year this study quantities characteristic abiotic stress. Below-average precipitation addition reduced water content suggests VOCs may driven primarily availability, factor limiting growth dryland agriculture. specific mechanisms driving changes not explicitly tested, work shows agricultural practices applied one season can differentially next through effects, illustrating additional avenues be leveraged management.