Location: Cropping Systems and Water Quality Research
Title: Water and nitrogen use efficiency of corn and switchgrass on variable claypan-soil landscapesAuthor
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Ransom, Curtis |
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Abendroth, Lori |
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BOARDMAN, DARA - Elemental Enzymes |
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Schreiner-Mcgraw, Adam |
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KITCHEN, NEWELL - Retired ARS Employee |
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 11/11/2024 Publication Date: 11/11/2024 Citation: Ransom, C.J., Abendroth, L.J., Boardman, D., Schreiner-Mcgraw, A.P., Kitchen, N. 2024. Water and nitrogen use efficiency of corn and switchgrass on variable claypan-soil landscapes [abstract]. ASA, CSSA, SSA International Annual Meeting, November 10-13, 2024, San Antonio, Texas. Paper No. 158748. Available: https://scisoc.confex.com/scisoc/2024am/meetingapp.cgi/Paper/158748 Interpretive Summary: Technical Abstract: The U.S. 2007 Renewable Fuel Standard mandates that by 2022 36 billion gallons of fuel originate from renewable sources, but caps corn (Zea mays L.) grain use at 15 billion. Therefore, other renewable sources, such as switchgrass (Panicum virgatum L.), need to be explored. Further, water and N are crucial but limited resources required for optimal crop production, and usage needs to be evaluated over variable soils. The objective of this research was to measure and compare water use efficiency (WUE) and crop N recovery efficiency (REN) from corn and switchgrass grown on variable claypan soil landscapes. Research was conducted in Missouri from 2009 to 2022 examining corn and switchgrass grown on plots constructed to represent a typical claypan soil landscape. Soils varied in the depth of topsoil (A and E horizons) above the initial argillic (Bt) horizon, referred to as depth to claypan (DTC). Water use efficiency for variable DTC was simulated using yield and an original water-balance model. Yield and N content in grain and switchgrass biomass were used to calculate REN. Switchgrass had higher WUE than corn (185-700%) for most growing seasons, generated less runoff (averaged 51%), but had more days of water stress (averaged ~50 d more annually). In dry years and depositional soils, switchgrass had higher WUE (21.9-27.7 kg ha^-1 mm^-1 greater) and REN (50-55% greater) than corn. These results quantify the level of drought tolerance switchgrass has compared to corn when these two crops are grown on claypan soils. These findings, along with knowledge of site-specific soil conditions, can help farmers decide where to grow perennial bioenergy crops in lieu of corn to optimize water and N resources and maximize bioenergy production. |