Scientific Information Launching Perennial Horizons
Scientific Information Launching Perennial Horizons

COBS Datasets

Accessing Data on SILPH

SILPH is a PostgreSQL database cluster running on a Microsoft Azure Flexible Server instance. The data within SILPH comes from and is accessible by large interdisciplinary teams at Iowa State University and partner organizations. Members of those teams that are Iowa State users can request access at silph@iastate.edu. Once authorized, users connected to the ISU VPN can make direct connections using PGadmin, DBeaver, R, Python, ArcGIS, QGIS, and many other programs. Team members that do not have access to the ISU VPN or do not wish to make a direct connection can access the data through our GitHub Team page after requesting access at silph@iastate.edu. Other arrangements for data access are also possible.

  • An aerial view of the plot layout at COBS. Photo credit: COBS.
    Authors:
    Matt Liebman, Matthew Helmers, Michael Thompson, Marshall McDaniel, Matthew Stephenson, Matt Woods, David Sundberg

    The Comparison of Biofuel Cropping Systems (COBS) experiment was designed to compare biomass production, fossil fuel replacement value, and environmental impacts for continuous corn grown for grain and stover removal with (CCW) and without (CC) a rye cover crop; multi-species perennial crops grown for aboveground biomass with (PF) and without (P) fertilizer; and a conventional corn-soybean grain system (C2, S2), used as a comparison baseline. The six treatments were randomly assigned to 27 x 61 m plots in four complete blocks. Plots were designed to be individually-drained by perforated tile lines such that drainage water could be sampled from the center portion of each plot without cross-plot contamination. 

    This dataset contains information on the management of the experimental site, including spatial layout and planting, harvesting, and pest management activities. Associated data sets contain information on corn, soybean, rye, and prairie grain and biomass yield; drainage volume and nutrient content; root growth; nutrient content of plant and soil material; soil moisture and bulk density; biodiversity; and solar radiation.

  • A small section of prairie with several species of grasses and forbs.
    Authors:
    Farnaz Kordbacheh, Meghann Jarchow, Lydia English, Matt Liebman

    Productivity and diversity of annually harvested reconstructed prairie communities database was compiled to test whether the long-term maintenance of biodiversity can be achieved alongside substantial productivity in fertilized mixed-species prairie. Using this database, we report how NPK fertilizer application, precipitation, and time affected the species composition and productivity of reconstructed prairie communities harvested annually as biofuel feedstocks over a nine-year period.
    Three main datasets were used for the analyses conducted, each encompassed a part of the full picture. First, we used dataset_productivity_precipitation_diversity to evaluate the relationship between productivity and precipitation. We also used this file to run the Analysis of Variance (ANOVA) on productivity, species richness, Simpson’s evenness and Simpson’s diversity. Results of this analysis are shown in Figure 1 and figure 2 of our article. Further, we used dataset_species_cover for the ANOVA on the cover of individual plant species, cover of functional groups-i.e. C3 grasses, C4 grasses, the non-leguminous, the leguminous and cover of forbs partitioned by flowering time (see Table 2, Figure 3 and Figure 4). For creating a complementary picture from changes in species composition over time and treatment, we used dataset_species_proportional_cover for multivariate analyses- i.e. non-metric multidimensional Scaling (NMDS), Multi Response-Permutation Procedure (MRPP), and the matching of
    ordination method (see Figure 5A and 5B). Usage of these datasets has no copyright or proprietary restrictions other than citation of the paper.