This repository contains the data and code used by Menalled and Ryan (2026) to evaluate sequences of rolled-crimped cover crops and no-till planted cash crops. The research evaluated in this repository reviewed 80 combinations of cover crops, cash crops, and management treatments across four site-years in a total of 1,280 experimental units. In the absence of supplemental management, cash crops exhibited a 2.6-fold mean difference in weed biomass and a 7.3-fold mean difference in yield when no-till planted into the best- versus worst-performing cover crops, indicating that cover crop selection is critical for defining the productivity of the subsequent cash crop.
Version control is done using the renv package. This package maintains a package library within the project folder. It is useful because it automatically restores all package versions that I used during my analysis to the within-project package library on your computer. Don’t worry, all changes will only be within the project and will not affect your R packages outside of this project. The renv package will automatically run when you open the project. Upon your first use of my project, you will have to restore all the packages that I used by running renv::restore() in your R console. To do this, you might have to make sure that your version of R is sufficiently up-to-date. Also, you will need to be connected to the internet. For more information on the renv package, see these wonderful YouTube videos: 1. https://youtu.be/Oen9xhEh8PY?si=wSyaMcTBm3LTK6OH 2. https://www.youtube.com/watch?v=yc7ZB4F_dc0
If the renv workflow is not working, you can remove the renv folder and renv.lock files from the project and manually install packages. However, this is not recommended as you will not be using the same package versions as I used during my analysis. Finally, please note that the renv package makes note of the R version I used the last time I saved my files (4.5.1, although I was using 4.4.0 during paper writing… results don’t change), but it will not change your R version.
This repository has also been uploaded to Zenodo for long-term storage:
- notill-sequences.Rproj: R project file
- CropAnalysis_pub.Rmd: Main code file. This is where all the analysis happened
- COOPData.csv: Data file
- Figures: A folder with all figures used for the paper
- renv: folder containing 1) the local Library of all packages that I used for the analysis and their version information, 2) an active.R file to tell R to match package version numbers, and 3) a setting.json file that stores all of the package information from my analysis
- renv.lock: A file that interfaces with the R project to maintain version control
- Site: Location of the data. Farm Hub (41° 54′ 35.96″, − 74° 5′ 29.41″) and Musgrave (42° 44′ 2.40″, − 76° 39′ 22.98″)
- Experiment: COOP1 and COOP3 are the two replicates of the winter cash crop experiment; COOP2 and COOP4 are the two replicates of the summer cash crop experiment
- Block: Block number within sites and experiments (i.e., Block 1 in Farm Hub / COOP1 is not the same as Block 1 in Farm Hub / COOP2)
- Plot.CashCrop: Plot number of cash crops within sites and experiments
- CoverCrop: Cover crop treatments. SS = is sorghum sudangrass, SH = sunn hemp, Hairy vetch = smooth vetch, HV = smooth vetch, CR = cereal rye
- CashCrop: Cover crop treatments. Wint. = Winter
- Management: Supplemental management treatments. Base = Baseline
- CropDens_PlantsHa: Cash crop density in plants per hectare
- WeedBiomass.CashCrop_KgHa: Dried weed biomass in the cash crops in Kilograms per hectare
- CropBiomass_KgHa: Dried cash crop biomass in Kilograms per hectare
- CropYield_KgHa: Moisture-adjusted cash crop yield in Kilograms per hectare: canola 10%, cereal rye 15%, dry bean 15%, soybean 13%, sunflower 10%, sweet corn 76%, winter pea 15%, and winter wheat 13.5%.
- CoverCropBiomass_KgHa: Dried cover crop biomass in Kilograms per hectare
- WeedBiomass.CovCrop_KgHa: Dried weed biomass in the cash crops in Kilograms per hectare
- Trial: Experiment name where “Winter” is the winter cash crop experiment and “Summer” is the summer cash crop experiment
- Experiment.Site.Block: Combination of the Experiment, Site, and Block variables
Information on data collection methods can be found in the methods section of the manuscript.