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 cover crop
biomass at termination for decision support tools.