Browsing by Author "Ewing, Patrick"

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    Microbial Husbandry: Nurturing Microbes to Capture Soil Ecosystem Services
    (2018-09) Ewing, Patrick
    Soil microbes drive many agroecosystem functions that dictate crop productivity, environmental outcomes, and management costs. Chapter 2 introduces microbial husbandry, a framework to manage soil microbes by creating soil conditions that allow critical taxa to thrive. Subsequent chapters apply microbial husbandry to nutrient cycling under maize (Zea mays L.) using a model system, ridge tillage and rye cover cropping (Secale cereale L.). We tested hypotheses with Bayesian structural equation modeling. In Chapter 3, arbuscular mycorrhizal fungi (AMF) insured against early season phosphorus (P) deficiency: AMF contributed to 40% higher maize P uptake in ridge till, at a 7% growth cost. Managers may increase P uptake by reducing physical disturbance to increase AMF abundance, and by increasing bulk density beyond levels in chisel plow. For Chapter 4, we wrote pyroots, a Python computer vision module, to measure roots and fungal hyphae in environmental samples cheaply and reproducibly (Appendix A; www.github.com/pme1123/pyroots). We also reported the first AMF hyphal length density values at 60 cm depth. Hyphal growth was independent of maize root growth, which suggests roots and hyphae can be managed independently. In Chapter 5, filamentous fungi acquired as much mineral nitrogen (N) as maize roots over five weeks after planting. While most root N uptake occurred in rows, fungal uptake occurred in both rows and inter-rows. Managers may encourage fungal N uptake without competing with crop needs by concentrating crop residue in the inter-rows. Overall, microbial husbandry helped us manage competing microbial functions simultaneously: nutrient provisioning in rows, and fertility building in inter-rows. Context-appropriate management tools can create soil conditions that enable microbes to perform these functions.
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    RCP-Minnetonka Green Roofs Report
    (Resilient Communities Project (RCP), University of Minnesota, 2013) Ewing, Patrick; Habeel, Nadine; Swanson, Chris; Tuladhar, Babina; Appleby, Elizabeth; Hampton, Kadence
    This project was completed as part of the 2012-2013 Resilient Communities Project (rcp.umn.edu) partnership with the City of Minnetonka. The City was interested in implementing green roofs as a priority environmental sustainability initiative, but was concerned about the physical and regulatory challenges, as well as public opposition. Minnetonka project lead and natural resources manager Jo Colleran partnered with students in AGRO 5321: Ecology of Agricultural Systems, and PA 5242: Environmental Planning, Policy, and Decision Making, to interview businesses and residents about their opinion of green roofs, research case studies of green roofs in northern climates, and develop best practice recommendations focused on policy, design, and maintenance. The final combined report, presentation, and poster from the two classes are available.
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    USDA-ARS Phenocart RGB Imagery Collected in Brookings, SD in 2021
    (2024-06-13) Ewing, Patrick; Runck, Bryan; patrick.ewing@usda.gov; Ewing, Patrick; Real-time Geoinformation Systems Lab, GEMS Informatics Center
    Data were collected from an experimental field in 2021 at the Eastern South Dakota Soil and Water Research Farm in Brookings, SD, USA (44.351 N, 96.805 W). The experiment consisted of a number of oat (Avena sativa L.) variety-by-seeding-rate treatments that were further divided into medium red clover planting treatments in a strip-block design with four replicates and a plot size of 6 m by 6 m. Oat treatments crossed variety (Reins, Natty, Sumo) and target oat population (140, 220, and 320 plants m-2) in 19 cm, drilled rows; red clover showed no responses to these oat treatments. Red clover treatments compared clover planted concurrently with oats (“underseeded”) on April 28, 2021; planted after oat harvest (“post-harvest”) on August 12, 2021; or no clover (“fallow”). Red clover was drilled at 1.25 cm depth at a rate of 8.2 kg ha-1 at a row spacing of 19 cm. An herbicide application of 210 g ha-1 sethoxydim (Poast, BASF Crop Protection, Research Triangle Park, North Carolina, USA), which selectively targets monocots, was applied on August 20, 2021, to control volunteer oats. A total of 720 RGB JPEG images were collected over six dates. The dates span the emergence of the post-harvest red clover planting to the first killing frost: August 21st, September 9th, September 29th, October 5th, October 15th, and October 25th. Images were collected by a Canon PowerShot ELPH 190 IS at a height of 2.5 m in the center of each plot using a phenotyping cart (White & Conley, 2013). To mirror the simplest use by researchers and practitioners, the camera was configured in full default, automatic mode, including ISO (a standard setting for controlling image darkness) and white balance and a 74-degree horizontal field of view. One image was taken from a representative location per plot on each date.