Report summary for the project period:

During this timeframe, year 1 of the experiment was established, in-season plant, soil, and water samples were collected, harvest was completed and preliminary analysis of in-season plant samples was conducted. While a central focus of this project is to use stable isotope methods to evaluate nitrogen in perennial groundcover (PGC) systems, no isotope analysis has been conducted yet. We anticipate this analysis to begin late February or early March 2025 and subsequent reports will include these data. Preliminary results are as follows: Read more about Investigating the Fate of Nitrogen Fertilizer in Perennial Groundcover Corn Cropping Systems Using 15N Stable Isotope Labeling Jan 2025

Since our last report we have completed the processing of all plant and soil materials collected in year 1 of the project. These samples are awaiting 15N isotopic analysis, which will be completed once the appropriate instrument has been installed and is operational. Read more about Investigating the Fate of Nitrogen Fertilizer in Perennial Groundcover Corn Cropping Systems Using 15N Stable Isotope Labeling Jul 2025

This project explores the viability of using a grassed waterway as an in-field practice for nitrate reduction in Northeast Iowa. Traditionally, saturating soils to improve nitrate reduction has been an edge-of-field practice. Read more about Extending saturated buffers to additional landscape positions Jul 2025

We have made strong progress on addressing how microbiome communities differ between woodchip and corncob reactors and the impacts of varying hydraulic retention times (HRTs). We have established which taxa correlate to nitrate removal efficiency, denitrification gene abundances (nirS, nirK, nosZ), and greenhouse gas emission rates (N₂O, CO₂, CH₄). We are also analyzing if low-performing bioreactors harbor similar microbial communities regardless of substrate type and HRT, suggesting universal signatures of poor performance. Read more about Unlocking the bioreactor microbiome for nutrient management and water quality Jul 2025

Activities this period focused on sample processing and enumeration and data entry, including counts of zooplankton, phytoplankton and benthic macroinvertebrates.

Activities and related accomplishments 

Partial filming for virtual field day, with further filming planned in summer 2025 and a presentation date in winter 2025/2026.

One student presentation on INRC work accepted for the 2025 Ecological Society of America conference in Baltimore, Maryland (Aug 10-15).  Read more about Co-benefits and possible unintended consequences of restoring wetlands for nutrient reduction Jul 2025