Water use by plant communities across years of varying water availability indicates how terrestrial water balances will respond to climate change and variability as well as to land cover change. Perennial biofuel crops, likely grown mainly on marginal lands of limited water availability, provide an example of a potentially extensive future land cover conversion. We measured growing-season evapotranspiration (ET) based on daily changes in soil profile water contents in five perennial systems—switchgrass, miscanthus, native grasses, restored prairie, and hybrid poplar—and in annual maize (corn) in a temperate humid climate (Michigan, USA). Three study years (2010, 2011 and 2013) had normal growing-season rainfall (480–610 mm) whereas 2012 was a drought year (210 mm). Over all four years, mean (±SEM) growing-season ET for perennial systems did not greatly differ from corn (496 ± 21 mm), averaging 559 (±14), 458 (±31), 573 (±37), 519 (±30), and 492 (±58) mm for switchgrass, miscanthus, native grasses, prairie, and poplar, respectively. Differences in biomass production largely determined variation in water use efficiency (WUE). Miscanthus had the highest WUE in both normal and drought years (52–67 and 43 kg dry biomass ha−1 mm−1, respectively), followed by maize (40–59 and 29 kg ha−1 mm−1); the native grasses and prairie were lower and poplar was intermediate. That measured water use by perennial systems was similar to maize across normal and drought years contrasts with earlier modeling studies and suggests that rain-fed perennial biomass crops in this climate have little impact on landscape water balances, whether replacing rain-fed maize on arable lands or successional vegetation on marginal lands. Results also suggest that crop ET rates, and thus groundwater recharge, streamflow, and lake levels, may be less sensitive to climate change than has been assumed.
Data table for Fig 1 b,c,d & Fig 2a in paper_ step-wise procedure to estimate ET from daily soil water content
This data file has the information of daily soil water of miscanthus (G6) for the year 2012 (as in fig 1 b,c,d) that demonstrates the step-wise procedure for water use calculation from daily soil water content. Each column in the data file has been described in a separate Readme.txt file.
Data table.xls
Data table for Fig 1 b, c, d & Fig 2a_ daily soil water content of different crops
This data file has information on the daily soil water content of different crops based on TDR measurements. Each column in the data file has been described in a separate Readme.txt file.
Data table for Fig 1a & 2a_ Precipitation
This data file has the information of daily precipitation (mm) recorded at the LTER station, KBS Hickory Corners, Michigan. Each column in the data file has been described in a separate Readme.txt file.
Data table for Fig 2b_ Maximum Biomass of switchgrass, miscanthus, prairie and grass mixture
This data table has the information of maximum biomass for switchgrass (G5), miscanthus (G6), native grass mixture (G7), and restored prairie (G10). Each column in the data file has been described in a separate Readme.txt file.
Data table for Fig 2b_ Maximum Biomass of corn
This data table has the information of maximum biomass for corn (G1). Each column in the data file has been described in a separate Readme.txt file.
Data table for Fig 2b_ Maximum Biomass of Poplar
This data table has the information of maximum biomass for hybrid poplar (G8) and made available from Poplar growth curves. Each column in the data file has been described in a separate Readme.txt file.
Data table for Fig 2c_WUE-biomass of all crops
This data table has the information of calculated WUE-maximum biomass (kg/ha/mm) for different crops. Each column in the data file has been described in a separate Readme.txt file
Data table for Fig 2d_Harvest yield
This data table has the information of harvest yield of corn (grain, corn stover and residual stover), switchgrass, miscanthus, grass mixture, hybrid poplar and restored prairie (whole biomass yield). Each column in the data file has been described in a separate Readme.txt file.
Data table for Fig S2_ Drained upper limit
This data table has information of drained upper limit (DUL) of the soil profile (0-150 cm) at the start of the growing season in each year based on TDR measurements. Each column in the data file has been described in a separate Readme.txt file.
Data table for Fig S3_Growing season lengths
This data table has information of growing season lengths of different cropping systems during the four years of study. Each column in the data file has been described in a separate Readme.txt file.
Data table for Fig S1_Percent of days using SALUS
This data table has information of percent of days during growing period when we used SALUS model to estimate the evapotranspiration.Each column in the data file has been described in a separate Readme.txt file.
National Science Foundation, Award: DEB 10277253
U.S. Department of Energy, Award: DE‐FC02‐07ER64494
U.S. Department of Energy, Award: DE-ACO5-76RL01830