Surface runoff and nutrient dynamics in cover crop–soybean systems in the Upper Midwest

Abstract

Relay‐cropping of the novel oilseeds winter camelina (Camelina sativa L.) and pennycress (Thlaspi arvense L.) with short‐season crops such as soybean [Glycine max (L.) Merr.] can provide economic and environmental incentives for adopting winter cover crop practices in the U.S. Upper Midwest. However, their ability to reduce nutrient loss in surface runoff is unknown. Accordingly, surface runoff and quality were evaluated during three seasonal phases (cover, intercrop, and soybean) over 2 yr in four cover crop–soybean treatments (pennycress, winter camelina, forage radish [Raphanus sativus L.], and winter rye [Secale cereale L.]) compared with no‐till and chisel‐till fallow treatments. Runoff was collected with Gerlach troughs and assessed for concentrations and loads of NO3−–N, total mineral N, soluble reactive P (SRP), and total suspended solids (TSS). Cumulative runoff and nutrient loads were greater during the winter cover phase because of increased snow melt and freeze–thaw released nutrients from living vegetation. In contrast, cumulative TSS was greater during intercrop and soybean phases due to high‐intensity rainfall events with an open soybean canopy. Average TSS loads during the intercrop phase were reduced by 75% in pennycress compared with fallow and radish treatments. During the soybean phase, average TSS, total mineral N, and SRP loads were generally elevated in cover crop treatments compared with no‐till. Overwintering cover crops may contribute to mobility of nutrients solubilized from living or decomposing vegetation; however, this was balanced by their potential to reduce runoff and TSS during high‐intensity spring rains.

Chromosome‐level Thlaspi arvense genome provides new tools for translational research and for a newly domesticated cash cover crop of the cooler climates

“…Pennycress is extremely winter hardy (Warwick et al ., 2002 ) and can be planted in traditional fallow periods following summer annuals such as wheat, maize or soya bean (Cubins et al ., 2019 ; Johnson et al ., 2015 ; Ott et al ., 2019 ; Phippen and Phippen, 2012 ). By providing a protective living cover from the harvest of the previous summer annual crop through early spring, pennycress prevents soil erosion and nutrient loss, which in turn protects surface and below‐ground water sources, suppresses early‐season weed growth, and provides a food source for pollinators (Del Gatto et al ., 2015 ; Johnson et al ., 2015 ; Weyers et al ., 2019 , 2021 ). The short life cycle allows for harvest in May or June in temperate regions, with reported seed yields ranging from 750 to 2400 kg/ha (Cubins et al ., 2019 ; Moore et al ., 2020 ).…”

Chromosome-level Thlaspi arvense genome provides new tools for translational research and for a newly domesticated cash cover crop of the cooler climates

“…Pennycress is extremely winter hardy (Warwick et al, 2002) and can be planted in traditional fallow periods following summer annuals such as wheat, maize or soybean (Cubins et al, 2019;Johnson et al, 2015;Ott et al, 2019;Phippen and Phippen, 2012). By providing a protective living cover from the harvest of the previous summer annual crop through early spring, pennycress prevents soil erosion and nutrient loss, which in turn protects surface and below-ground water sources, suppresses early-season weed growth, and provides a food source for pollinators (Johnson et al, 2015;Weyers et al, 2021Weyers et al, , 2019Eberle et al, 2015). The short life cycle allows for harvest in May or June in temperate regions, with reported seed yields ranging from 750 to 2400 kg ha -1 (Cubins et al, 2019;Moore et al, 2020).…”

Plant Breeding for Intercropping in Temperate Field Crop Systems: A Review

“…Intercropping represents within-field diversity, is defined as growing two or more crop species simultaneously in the same field, and encompasses a range of practices including mixed intercropping (growing component crops simultaneously with no distinct row arrangement), row intercropping (growing component crops simultaneously in different rows), strip intercropping (growing component crops simultaneously in different strips), and relay intercropping (growing component crops with overlapping growth periods; Andrews and Kassam, 1976 ). Intercropping can provide valuable benefits, including increased yield ( Trenbath, 1974 ; Hauggaard-Nielsen et al, 2001 ; Nyfeler et al, 2009 ; Finn et al, 2013 ; Martin-Guay et al, 2018 ; Li et al, 2020 ), yield stability ( Rao and Willey, 1980 ; Raseduzzaman and Jensen, 2017 ), improved crop quality ( Sleugh et al, 2000 ; Bélanger et al, 2014 ), reduced pest and disease impacts ( Altieri, 1999 ; Boudreau, 2013 ; Gaba et al, 2015 ), improved weed management ( Hauggaard-Nielsen et al, 2001 ; Finn et al, 2013 ; Johnson et al, 2017 ; Connolly et al, 2018 ; Hoerning et al, 2020 ), reduced input needs ( Nyfeler et al, 2009 ; Gaba et al, 2015 ; Raskin et al, 2017 ), improved soil health ( Cong et al, 2015 ; Li et al, 2021 ), support for a wide range of native pollinators ( Eberle et al, 2015 ; Forcella et al, 2021 ), and a range of other ecosystem services, such as wildlife conservation, soil conservation, water quality improvements ( Weyers et al, 2021 ), and carbon sequestration ( Malézieux et al, 2009 ). Intraspecific diversity in the form of cultivar mixtures can provide benefits for productivity and resilience ( Reiss and Drinkwater, 2018 ), but this review focuses on interspecific diversity through intercropping.…”