Upscaling Gross Primary Production in Corn-Soybean Rotation Systems in the Midwest

Remote Sensing

DarrenT. Drewry¹  MichaelH. Cosh²  JohnH. Prueger³  KenM. Wacha³  JerryL. Hatfield³  Christian Dold³  TomB. Moorman³  TomJ. Sauer³ 

[1] Department of Food, Agricultural and Biological Engineering, The Ohio State University, Columbus, OH 43210, USA;USDA-ARS, Hydrology and Remote Sensing Laboratory, BARC-West, Beltsville, MD 20705, USA;USDA-ARS, National Laboratory for Agriculture and the Environment, Ames, IA 50011, USA;

关键词: ACPF;    eddy covariance;    MODIS fPAR;    NDVI;    radiation use efficiency;   

DOI  :  10.3390/rs11141688

来源: DOAJ

【 摘 要 】

The Midwestern US is dominated by corn (Zea mays L.) and soybean (Glycine max [L.] Merr.) production, and the carbon dynamics of this region are dominated by these production systems. An accurate regional estimate of gross primary production (GPP) is imperative and requires upscaling approaches. The aim of this study was to upscale corn and soybean GPP (referred to as GPP_calc) in four counties in Central Iowa in the 2016 growing season (DOY 145−269). Eight eddy-covariance (EC) stations recorded carbon dioxide fluxes of corn (n = 4) and soybean (n = 4), and net ecosystem production (NEP) was partitioned into GPP and ecosystem respiration (RE). Additional field-measured NDVI was used to calculate radiation use efficiency (RUE_max). GPP_calc was calculated using 16 MODIS satellite images, ground-based RUE_max and meteorological data, and improved land use maps. Seasonal NEP, GPP, and RE ( $\overline{x}$ ± SE) were 678 ± 63, 1483 ± 100, and −805 ± 40 g C m⁻² for corn, and 263 ± 40, 811 ± 53, and −548 ± 14 g C m⁻² for soybean, respectively. Field-measured NDVI aligned well with MODIS fPAR (R² = 0.99), and the calculated RUE_max was 3.24 and 1.90 g C MJ⁻¹ for corn and soybean, respectively. The GPP_calc vs. EC-derived GPP had a RMSE of 2.24 and 2.81 g C m⁻² d⁻¹, for corn and soybean, respectively, which is an improvement to the GPP_MODIS product (2.44 and 3.30 g C m⁻² d⁻¹, respectively). Corn yield, calculated from GPP_calc (12.82 ± 0.65 Mg ha⁻¹), corresponded well to official yield data (13.09 ± 0.09 Mg ha⁻¹), while soybean yield was overestimated (6.73 ± 0.27 vs. 4.03 ± 0.04 Mg ha⁻¹). The approach presented has the potential to increase the accuracy of regional corn and soybean GPP and grain yield estimates by integrating field-based flux estimates with remote sensing reflectance observations and high-resolution land use maps.

【 授权许可】

Unknown