Abstract

Cover crops are planted during the off-season to protect the soil and improve watershed management. The ability to map cover crop termination dates over agricultural landscapes is essential for quantifying conservation practice implementation, and enabling estimation of biomass accumulation during the active cover period. Remote sensing detection of end-of-season (termination) for cover crops has been limited by the lack of high spatial and temporal resolution observations and methods. In this paper, a new within-season termination (WIST) algorithm was developed to map cover crop termination dates using the Vegetation and Environment monitoring New Micro Satellite (VENµS) imagery (5 m, 2 days revisit). The WIST algorithm first detects the downward trend (senescent period) in the Normalized Difference Vegetation Index (NDVI) time-series and then refines the estimate to the two dates with the most rapid rate of decrease in NDVI during the senescent period. The WIST algorithm was assessed using farm operation records for experimental fields at the Beltsville Agricultural Research Center (BARC). The crop termination dates extracted from VENµS and Sentinel-2 time-series in 2019 and 2020 were compared to the recorded termination operation dates. The results show that the termination dates detected from the VENµS time-series (aggregated to 10 m) agree with the recorded harvest dates with a mean absolute difference of 2 days and uncertainty of 4 days. The operational Sentinel-2 time-series (10 m, 4–5 days revisit) also detected termination dates at BARC but had 7% missing and 10% false detections due to less frequent temporal observations. Near-real-time simulation using the VENµS time-series shows that the average lag times of termination detection are about 4 days for VENµS and 8 days for Sentinel-2, not including satellite data latency. The study demonstrates the potential for operational mapping of cover crop termination using high temporal and spatial resolution remote sensing data.

Highlights

  • Cover crops are planted after a field is harvested to cover the soil for the benefit of the agroecosystem

  • Our results show that cover crop termination dates can be reliably detected using high temporal and spatial resolution satellite imagery

  • Mapping termination dates for cover crops within the season using remote sensing has been challenging in the past due to the lack of high temporal and spatial resolution data

Read more

Summary

Introduction

Cover crops are planted after a field is harvested to cover the soil for the benefit of the agroecosystem. Different from cash crop production, cover crops are mainly used to reduce soil erosion, increase soil fertility, and improve watershed management [1,2,3] They can be used as “green manures” and plowed before reaching full maturity to provide nitrogen for cash crop production [4] can increase soil organic matter levels and soil carbon sequestration [2]. Another benefit is that cover crops can retain soil nitrogen from chemical nitrogen fertilizer for cash crops and reduce leaching of farmland nitrogen to the groundwater and watershed surface waters [5]. Cost-share programs have been created to encourage the planting of cover crops for improving water quality [8]

Objectives
Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call