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Research article - Peer-reviewed, 2022

Agronomic performance, nitrogen acquisition and water-use efficiency of the perennial grain crop Thinopyrum intermedium in a monoculture and intercropped with alfalfa in Scandinavia

Martensson, Linda-Maria Dimitrova; Barreiro, Ana; Li, Shoujiao; Jensen, Erik Steen;

Abstract

The perennial forage grass Thinopyrum intermedium (Host) Barkworth & Dewey, commonly known as intermediate wheatgrass (IWG) or by the commercial name Kernza (TM), is being developed as a perennial grain crop, i.e. being bred for its improved agronomic performance and food qualities. Intercropping legumes and grasses is a strategy for improving resource use and sustainability in cropping systems. Here, we show for the first time the agronomic performance of IWG as a perennial cereal grown as a monocrop and as an intercrop (alternate row, 0.5:0.5) with Medicago sativa L. (alfalfa/lucerne) in southern Sweden. The seeds of cycle 3 IWG were accessed from The Land Institute (TLI) of Salinas, Kansas, USA, and used to establish a local seed production plot (in 2014) for the establishment of the perennial systems (in 2016) utilised in this study. Both the monocrop and intercrop were sown with 25 cm row spacing with alternate rows of IWG and alfalfa in the intercrop (i.e. replacement design) with unknown sowing density. Intercropping provided sustained IWG grain production under the dry conditions of 2018, but also in the following year. This was evidently associated with a higher nitrogen accumulation in intercropped practice. Thus, intercropping seems to have stabilised the IWG grain production in the dry conditions of 2018, when the grain production in the intercrop was similar to that of the monocrop in the same year. This result was further supported by the lower discrimination against C-13 (as an indicator of water use efficiency) in the intercrop components compared to the sole crop in 2018. The lower discrimination indicates high water use efficiency in the intercropped IWG in comparison to the IWG in monoculture, and we conclude that intercropping perennial cereal grain crops with legumes provides better growing conditions in terms of nitrogen acquisition, and water status, to cope with more extreme drought spells expected from climate change.

Keywords

Intermediate wheatgrass; Grain yield; Straw yield; Drought; N content; N-2 fixation; Lucerne

Published in

Agronomy for Sustainable Development

2022, volume: 42, number: 2, article number: 21
Publisher: SPRINGER FRANCE

Authors' information

Barreiro, Ana
Swedish University of Agricultural Sciences, Department of Biosystems and Technology
Swedish University of Agricultural Sciences, Department of Biosystems and Technology
Swedish University of Agricultural Sciences, Department of Biosystems and Technology

Sustainable Development Goals

SDG2 Zero hunger

UKÄ Subject classification

Agricultural Science

Publication Identifiers

DOI: https://doi.org/10.1007/s13593-022-00752-0

URI (permanent link to this page)

https://res.slu.se/id/publ/116459