Data and code from: Sowing date and seeding rate influence cereal rye productivity across the Northeastern United States

Improving the management of cereal rye (Secale cereale L.), the most frequently used cover crop in the United States, provides an opportunity to enhance agroecosystem service provisioning. Services such as erosion control, weed suppression, and nitrate leaching mitigation are correlated with cereal rye ground cover and biomass, which decline as sowing dates are delayed. Our objective was to quantify whether increasing cereal rye seeding rates could compensate for lost growing degree days as sowing is delayed across the Northeastern United States, and if early spring ground cover could predict late spring biomass and guide grower decision making. We established a two-factor experiment across 13 site-years to test the effects of sowing date, relative to the historic first frost date of each location, and seeding rate (0, 17, 34, 67, 101, and 135 kg ha−1) on cereal rye productivity and weed suppression. Delaying sowing from 2 weeks before to 2 weeks after the historic first frost date..., , # Data and code from: Sowing date and seeding rate influence cereal rye productivity across the Northeastern United States

Dataset DOI: [10.5061/dryad.zkh1893rm](https://doi.org/10.5061/dryad.zkh1893rm)

## Description of the data and file structure

Data were collected to assess cereal rye productivity in response to seeding rate (n=6) and sowing date (n=3). Data were collected from field trials at 13 site-years across the Northeastern US. 

Data collection included cereal rye stand counts (plants/m2) conducted 3 weeks after sowing, ground cover (fractional green canopy cover; %) using smartphone images and the Canopeo app, cereal rye biomass at mid-anthesis (kg/ha), and weed biomass in cereal rye at mid-anthesis (kg/ha). 

Soil data (nitrate-N, P, pH, organic matter) were collected at each sowing date at each site-year. 

Growing degree days (GDDs) were calculated using the Baskerville and Emin sine method (base temperature 4.4C) between sowing and mid-anthesis, when biomass was harv..., ,