The surface-atmosphere exchange of carbon dioxide, water, and sensible heat across a dryland wheat-fallow rotation

摘要: Abstract Summer fallow – the practice of keeping a field out production during growing season is common in dryland wheat (Triticum aestivum L.) cropping systems to conserve soil water resources. Fallow also depletes carbon stocks and thereby quality. The area summer has decreased by tens millions hectares since 1970s northern North American Great Plains as producers have recognized that avoiding usually confers both economic conservation benefits. Observed summertime cooling across parts this region coincided with reduction, suggesting role atmospheric processes needs be ascertained. We measured dioxide, latent heat, sensible heat flux winter spring sequence Montana, USA determine effects crop management on ecosystem resources energy partitioning at surface-atmosphere interface. Winter fields were sinks (Fc = −203 ± 52 g C CO2 m−2 −107 ± 29 g CO2 m−2), respectively, April September study period, but was source 135 ± 73 g CO2 m−2. Evapotranspiration crops over 100 mm greater than 275 ± 39 mm observed period. Modeled maximum daily boundary layer height average 210 m higher up 900 m compared more crossings modeled lifted condensation level, regional studies near-surface temperature moisture are necessary understand reduction climate dynamics. Results demonstrate detrimental impact yet less intensive, consequences for via its impacts development global metabolism.