Remote sensing evaluation of winter cover crop springtime performance and the impact of delayed termination

Alison Thieme; W. Dean Hively; Feng Gao; Jyoti Jennewein; Steven Mirsky; Alexander M. Soroka; Jason Keppler; Dawn Bradley; Sergii Skakun; Gregory W. McCarty

doi:10.1002/agj2.21207

USGS · 70242665

Remote sensing evaluation of winter cover crop springtime performance and the impact of delayed termination

Alison Thieme·W. Dean Hively·Feng Gao·Jyoti Jennewein·Steven Mirsky·Alexander M. Soroka·Jason Keppler·Dawn Bradley·Sergii Skakun·Gregory W. McCarty

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Abstract

In 2019, the Maryland Department of Agriculture's Winter Cover Crop Program introduced a delayed termination incentive (after May 1) to promote springtime biomass accumulation. We used satellite imagery calibrated with springtime in situ measurements collected from 2006–2021 ( n = 722) to derive biomass estimates for Maryland fields planted to cereal cover crop species (286,200 ha total over two seasons). Cover crop C content remained steady throughout the cover crop growing season (42.6% of biomass), whereas N concentration had an inverse relationship with biomass and ranged from 1.7 to 2.9%. Throughout Maryland, delayed termination fields ( n = 19,120; average termination of May 18) were, on average, estimated to accumulate an additional 789 kg of biomass, 15 kg of N, and 336 kg of C per hectare when compared to fields associated with standard termination dates ( n = 28,811; average termination of April 16). Over two cover crop seasons (2019–2021), the delayed termination incentive yielded an extra 75,660,000 kg biomass, 1,526,000 kg N, and 32,230,000 kg C across 96,040 hectares. Regularly terminated field incentives cost an average of US$0.10 per kg of biomass and $4.09 per kg of N, with variability associated with agronomic management (species, planting method). Delayed termination fields cost of $0.08 per kg of biomass and $3.51 per kg of N. Late-planted cover crops that were terminated early had minimal environmental benefit, and wheat, which comprised 68% of cover crop area, performed poorly compared with other cereal species. Our findings demonstrate that substantial additional springtime biomass, C, and N accumulation were achieved through the delayed termination incentive.

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Source-reported bounding extent: 37.911717° to 39.721811° latitude; -79.486862° to -75.049268° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Alison Thieme, W. Dean Hively, Feng Gao, Jyoti Jennewein, Steven Mirsky, Alexander M. Soroka, Jason Keppler, Dawn Bradley, Sergii Skakun, Gregory W. McCarty. 2023-01-11. Remote sensing evaluation of winter cover crop springtime performance and the impact of delayed termination. https://doi.org/10.1002/agj2.21207

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