Cover Crop Influence on Arthropod Biodiversity and Soil–Water Dynamics in a Semi-arid Maize–Soybean Sequence of the Nebraska High Plains

Authors

Carlos Eduardo De Oliveira Martins, University of Nebraska-LincolnFollow

First Advisor

Nicolas Cafaro La Menza

Committee Members

Abia Katimbo, Andrea Basche, Cody F. Creech, Julie Peterson

Date of this Version

12-2025

Document Type

Thesis

Citation

A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Agronomy

Under the supervision of Professor Nicolas Cafaro La Menza

Lincoln, Nebraska, December 2025

Comments

Copyright 2025, Carlos Eduardo de Oliveira Martins. Used by permission

Abstract

With the expansion of cover crop (CC) use in semi-arid regions, producers in the Nebraska High Plains are increasingly interested in understanding how CCs influence both beneficial arthropods and soil-water within maize-soybean (Zea mays L., Glycine max [L.] Merr.) rotations. Integrating CCs in these systems can enhance soil water availability and beneficial insect activity, but potential trade-offs include higher early-season water use by CCs and the risk of increasing potential pest populations. This thesis addresses these questions through two complementary studies conducted under field conditions near Brule, Nebraska. The first study evaluated the effects of a multi-species CC mixture on epigeal and aerial arthropod communities, revealing that even limited CC biomass in this semi-arid system was sufficient to alter arthropod community structure. The CC increased potential pest abundance in both aerial and epigeal communities, while natural enemy responses were modest and inconsistent. Seasonal dynamics were the primary drivers of arthropod abundance, with activity peaking at critical crop stages such as flowering, indicating a key biological window that warrants further investigation. Crop yields remained largely unaffected by CC. The second study examined how CCs influence soil-water dynamics under different levels of water regimes. Soil moisture was monitored using neutron probe readings at multiple depths to assess treatment effects on soil-water storage and availability during the growing season. The CC had minimal influence on soil moisture before soybeans but reduced early-season soil-water storage before maize under limited-water conditions, contributing to lower maize yields when following rye. Water regime was the dominant driver of soil-water availability and soybean productivity, with CC effects secondary to irrigation in this semi-arid system. Overall, this work provides an insight into ecological and hydrological implications of CC adoption in semi-arid cropping systems. The findings aim to inform sustainable management strategies that balance productivity, biodiversity conservation, and soil-water dynamics in the Nebraska High Plains region.

Advisor: Nicolas Cafaro La Menza