@article{804312c19b61412e837edaa2f4ea30a9,
title = "Photosynthesis, yield, energy balance, and water-use of intercropped maize and soybean",
abstract = "By 2050, the U.S. Corn Belt will likely face a 23% increase in leaf-to-air vapor pressure deficit (VPDL), the driving force of evapotranspiration (ET), which may restrict maize yield improvements for rainfed agroecosystems. Alternative cropping systems, such as maize and legume intercrops, have previously demonstrated yield and resource-use advantages over monocultures. In this study, the residual energy balance approach was used to gain insights into how an additive simultaneous maize and soybean intercrop system regulates ET and water-use efficiency (WUE) compared to standard maize and soybean monoculture systems of the U.S. Corn Belt. Experimental field plots were rain-fed and arranged in a randomized complete block design in three blocks. Photosynthetic capacity and grain yield of maize were conserved in the intercrop. However, its competitive dominance shaded 80%–90% of incident light for intercropped soybean at canopy closure, leading to a 94% decrease in grain yield compared to soybean monoculture. The total grain yield per unit area of the additive intercrop (land-use efficiency) increased by 11% ± 6% (1 SE). Compared to maize monoculture, the intercrop had higher latent heat fluxes (λET) at night but lower daytime λET as the intercrop canopy surface temperature was approximately.25°C warmer, partitioning more energy to sensible heat flux. However, the diel differences in λET fluxes were not sufficient to establish a statistically significant or biologically relevant decrease in seasonal water-use (ΣET). Likewise, the increase in land-use efficiency by the intercrop was not sufficient to establish an increase in seasonal water-use efficiency. Intercropping high-performing maize and soybean cultivars in a dense configuration without negative impact suggests that efforts to increase yield and WUE may lead to improved benefits.",
author = "Pelech, {Elena A.} and Alexander, {Brendan C.S.} and Bernacchi, {Carl J.}",
note = "Funding Information: This work was funded by the USDA to the Global Change and Photosynthesis Research Unit of the USDA Agricultural Research Service. Mention of trade names or commercial products in this publication is solely to provide specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the U.S. Department of Agriculture. The authors thank Tim Mies, David Drag, Ben Harbaugh, Ben Thompson, and Trace Elliot for their management and assistance of the Energy Farm Facility and preparations of the field for this project. The authors also thank Taylor Pederson, David Drag, Evan Dracup, Caitlin Moore, Emily Timm, Marshall Mitchell and Pietro Hughes for their assistance with data collection and sensor maintenance. Funding Information: This work was funded by the USDA to the Global Change and Photosynthesis Research Unit of the USDA Agricultural Research Service. Mention of trade names or commercial products in this publication is solely to provide specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the U.S. Department of Agriculture. The authors thank Tim Mies, David Drag, Ben Harbaugh, Ben Thompson, and Trace Elliot for their management and assistance of the Energy Farm Facility and preparations of the field for this project. The authors also thank Taylor Pederson, David Drag, Evan Dracup, Caitlin Moore, Emily Timm, Marshall Mitchell and Pietro Hughes for their assistance with data collection and sensor maintenance. Publisher Copyright: {\textcopyright} 2021 The Authors. Plant Direct published by American Society of Plant Biologists and the Society for Experimental Biology and John Wiley & Sons Ltd. This article has been contributed to by US Government employees and their work is in the public domain in the USA.",
year = "2021",
month = dec,
doi = "10.1002/pld3.365",
language = "English (US)",
volume = "5",
journal = "Plant Direct",
issn = "2475-4455",
publisher = "John Wiley & Sons, Ltd.",
number = "12",
}