Impact of Cover Crop Planting and Termination Dates on Arthropod Activity in the Following Corn

Abstract

Relative to fallow-cash crop rotations, the addition of a cover crop can contribute to greater plant diversity and has the potential to conserve predatory arthropods. The transition of arthropods from a cover crop to a subsequent cash crop depends on several factors, such as cover crop biomass production and weather conditions. Information about the effect of cover crop planting and termination dates on arthropods in a subsequent corn system is limited. A two-year field study was conducted in Nebraska in 2018/2019 and 2019/2020 to evaluate the impact of cover crop planting and termination dates as a source for arthropods in the subsequent corn. A total of 38,074 and 50,626 arthropods were collected in the first and second year, respectively. In both years, adding a grass cover crop increased predatory arthropods but reduced yield in follow corn crop. Of the arthropods collected, Carabidae and Araneae had greater activity with cover crop biomass increments, whereas Collembola and Acari activity only increased in treatments with little or no cover crop biomass. Insect pest pressure was not significant in any treatment for either year. A cover crop planted in mid- or late-September and terminated at corn planting was identified as the best management strategy to maximize cover crop biomass, increase predator activity, and modify predator-prey dynamics. The results of this study provide growers with a cover crop management strategy to maximize cover crop biomass, beneficial arthropod activity, and potentially minimize insect pest problems; however, corn Zea Mays (L.) grain yield was reduced as cover crop biomass increased.

Evaluating the impact of at-plant termination of a cereal rye cover crop with different corn planting dates on arthropod activity

“…Pitfall traps were used to estimate the ground-dwelling arthropod activity with a focus on three sampling times that span the period of transition between the cover crop to corn. The pitfall trap design followed Carmona et al (2022) with one pitfall placed in the center of each split-plot. Arthropod activity during the transition from cover crop to corn was evaluated by placing pitfall traps at the early (hereafter: sample one) and late corn planting dates (hereafter: sample two) as well as at the first corn injury assessment (hereafter: sample three).…”

“…More recently, Rosa et al (2021) performed field studies in western Nebraska, in a semi-arid environment, and reported that cover crops reduced maize grain yield regardless of the termination timing. Carmona et al (2022) also found decreased corn yields when cover crop biomass was increased. Even though having a decent cover crop biomass is frequently the goal for growers, any loss in the production of corn is likely a serious concern and potential impediment for growers when adopting cover crops.…”

“…For arthropods, a delay in cover crop termination is expected to increase biomass accumulation resulting in a more complex and favorable habitat for beneficial arthropods (Ward et al 2011, Rivers et al 2018, Shearin et al 2008, Carmona et al 2022). A recent two-year field study reported a significant increase in Araneae activity with management strategies that increased cover crop biomass (Carmona et al 2022).…”

“…For arthropods, a delay in cover crop termination is expected to increase biomass accumulation resulting in a more complex and favorable habitat for beneficial arthropods (Ward et al 2011, Rivers et al 2018, Shearin et al 2008, Carmona et al 2022). A recent two-year field study reported a significant increase in Araneae activity with management strategies that increased cover crop biomass (Carmona et al 2022). The study found that planting a cereal rye-oat cover crop mix in early or mid-September combined with a late termination of the cover crop at corn planting resulted in the greatest cover crop biomass and greater Araneae activity (Carmona et al 2022).…”

“…A recent two-year field study reported a significant increase in Araneae activity with management strategies that increased cover crop biomass (Carmona et al 2022). The study found that planting a cereal rye-oat cover crop mix in early or mid-September combined with a late termination of the cover crop at corn planting resulted in the greatest cover crop biomass and greater Araneae activity (Carmona et al 2022). Moreover, Shearin et al (2008) had previously found that more cover crop biomass attracted and retained more carabids (Order: Coleoptera) in the system compared to treatments with less biomass accumulation.…”