Successional resistance: leveraging soil legacy to manipulate chemical ecology and promote plant protection

Harnessing Soil Legacy Effects for Sustainable Plant ProtectionSoil legacy effects present a largely untapped opportunity to improve plant protection by manipulating belowground chemical ecology. Despite the critical role soil interactions play in determining plant health and crop resilience, these dynamics remain one of the least explored facets of agricultural research. Historically, agricultural practices have centered on abiotic factors, such as chemical treatments and physical soil manipulation, while the intricate biological and ecological dynamics within soil have been underappreciated. Addressing the complexity of functional soil health demands a holistic, interdisciplinary approach that integrates chemical, biological, and ecological knowledge.Our preliminary studies demonstrate that the choice of cover crops can leave lasting impacts on the resistance of subsequent cash crops to key pests, such asSpodoptera frugiperda(Fall Armyworm),Rhopalosiphum maidis(Corn Leaf Aphid), andDiabrotica virgifera(Western Corn Rootworm), as well as pathogens like Southern Corn Leaf Blight andFusarium verticillioides. Moreover, cover crops influence beneficial natural enemy activity and foster stronger associations with beneficial soil fungi, underscoring the critical role of the soil microbiome in mediating these interactions.Building on these findings, this project aims to investigate the breadth and mechanisms of soil legacy effects, identify key components of these systems, and evaluate whether an optimal mix of cover crops can provide multi-layered resistance to pests and pathogens while improving crop yields. By focusing on the chemical and biological ecology underlying plant-soil-microbe interactions, the project seeks to develop sustainable strategies that reduce pest and pathogen pressure and recruit beneficial organisms for enhanced plant protection.Specific ObjectivesEvaluate the Impact of Cover Crops on Constitutive and Induced Defenses in Diverse Maize Cultivars and Soil TypesWe aim to determine how cover crop-induced soil changes influence both the baseline (constitutive) and responsive (induced) defenses of maize against pests and pathogens. By studying different maize cultivars and soil types, this objective will reveal the robustness and variability of cover crop effects across diverse agricultural contexts.Assess Pest and Natural Enemy Interactions Across Maize Cultivars and Soil TypesThe project will examine whether soil changes resulting from different cover crops affect pest and natural enemy behaviors. Specifically, we will evaluate pest feeding preferences and natural enemy attraction across various maize cultivars and soil conditions, providing insights into how soil legacy effects shape multitrophic interactions.Optimize Pest Resistance and Natural Enemy Attraction Using Soil MixturesWe aim to test whether soil mixtures derived from different cover crop legacies can enhance pest resistance and natural enemy attraction in maize. This objective will focus on identifying combinations of cover crop species that maximize beneficial interactions while minimizing pest and pathogen pressures.Identify Mechanisms Driving Soil Biota-Plant Chemistry-Insect Response CascadesBy integrating chemical ecology, soil microbiology, and plant-insect interactions, this objective seeks to uncover the mechanisms through which cover crops influence soil biota, plant chemical signaling, and subsequent pest and natural enemy responses.Expand Knowledge Across Geographic Locations and Field SettingsTo ensure the broad applicability of findings, we will evaluate cover crop effects on maize defense in soils from multiple locations and under diverse field conditions. This will help determine the consistency of outcomes across environmental and management contexts.