Early-season biomass and weather enable robust cereal rye cover crop biomass predictions

Farmers need accurate estimates of winter cover crop biomass to make informed decisions on termination timing or to estimate potential release of nitrogen from cover crop residues to subsequent cash crops. Utilizing data from an extensive experiment across 11 states from 2016 to 2020, this study explores the most reliable predictors for determining cereal rye cover crop biomass at the time of termination. Our findings demonstrate a strong relationship between early-season and late-season cover crop biomass. Employing a random forest model, we predicted late-season cereal rye biomass with a margin of error of approximately 1,000 kg ha-1 based on early-season biomass, growing degree days, cereal rye planting and termination dates, photosynthetically active radiation, precipitation, and site coordinates as predictors. Our results suggest that similar modeling approaches could be combined with remotely sensed early-season biomass estimations to improve the accuracy of predicting winter cove..., 2.1 Field sites and operations
 
Cereal rye cover crop biomass data used in the modeling approach were obtained from a field experiment conducted on research farms in 11 states between 2016 and 2020 (as outlined in Supplementary Table 1). Cereal rye was planted in 9.1 by 12.2 m plots in the late fall of each year, with four or five replicates per site-year. Management practices (i.e., cereal rye variety, seeding rates and methods) specific to each site were based on local norms. Biomass samples were collected from two 0.5-m2 quadrats in each plot at six weeks (hereafter referred to as “early-season biomass”) and two weeks (“late-season biomass”) prior to target dates for soybean planting. Cereal rye variety, as well as cereal rye planting and early and late-season biomass dates are summarized across sites and years in Supplementary Table 2.
 
2.2 Data assembly and preparation
 
In addition to early-season biomass, which was hypothesized to predict winter cover crop growth, weather varia..., , # Early-season biomass and weather enable robust cereal rye cover crop biomass predictions

Utilizing data from an extensive experiment across 11 states from 2016 to 2020, this study explores the most reliable predictors for determining cereal rye cover crop biomass at the time of termination. The dataset includes experimental data such as early-season biomass, cereal rye planting and termination dates, and site coordinates, and we extracted weather data such as growing degree days, photosynthetically active radiation, and precipitation to predict cereal rye biomass at the time of termination.

## Description of the data and file structure

Two data files are included; first, the \"experimental_data.csv\" which includes all of the data describing and collected as a result of the field experiments. Another file \"experimental_and_weather_data.csv\" joins the weather and experimental data. All columns are defined in detail in the \"data_dictionary.csv\" file. \"NA\" entries correspond to missi...