Vigor and Persistence of Birdsfoot Trefoil Populations Selected with or without an Orchardgrass Companion Evaluated in Grass Sod

Abstract

RESEARCHI n the United States approximately 37% of nonfederal land in the lower 48 states is either rangeland, pasture, or in the Conservation Reserve Program ( Barnes and Nelson, 2003), although more recent changes in commodity prices likely have caused this number to decline (Wright and Wimberly, 2013). Forage legumes are very often a part of these grasslands and pastures. Forage legume breeders therefore often consider the merits of incorporating grass competition in their variety development programs. Breeding plants specifically adapted to competitiveness in mixture is not unique to forage breeding for pasture use but has been broadly considered for intercropping systems as well (Brummer, 2008). Two pertinent examples include breeding for increased bean (Phaseolus vulgaris L.) and maize (Zea mays L.) yield in intercropped mixtures (Zimmermann, 1997) and breeding white clover (Trifolium repens L.) for increased competitiveness in mixture with grass (Annicchiarico, 2003). Breeding methodology and theory to assist in this endeavor have been proposed and reviewed (Hamblin et al., 1976;Hill et al., 1998;Brummer, 2008).Particularly germane to forage legume breeding is the case of breeding white clover specifically for competitive ability in mixtures with grass. This is likely because of white clover's almost exclusive use in mixtures with grass. White clover-grass mixture ABSTRACT Forage legumes are often grown in mixtures with grass for grazing or harvested for hay or silage. Forage legume breeders often debate the necessity of incorporating grass competition into the breeding process, particularly when bred varieties will be used in mixture with grass. To address this debate, a two by two by two factorial of eight birdsfoot trefoil (Lotus corniculatus L.) populations were developed from selections of plants made at two nursery sites (Boone, IA, and Prairie du Sac, WI), out of two base cultivars (Norcen and WITT), and under two nursery treatments [orchardgrass (Dactylis glomerata L.) overseeded and no-grass overseeded]. Spaceplants of the eight birdsfoot trefoil populations were transplanted directly into grass sod and evaluated for 4 yr for visual vigor (a proxy for biomass yield) and plant persistence. Persistence over time was measured using a linear model describing the decline in stand percentage per month. Overall, the four birdsfoot trefoil populations bred with a grass companion persisted better when transplanted into grass sod (slope -1.12% persistence mo -1 ) compared with the four birdsfoot trefoil population bred without a grass companion (slope -1.43% persistence mo -1 ). On average, only the WITT-derived populations selected with a grass companion had superior visual vigor ratings when transplanted into sod compared with the WITT-derived populations selected without a grass companion. This study provides evidence that selecting birdsfoot trefoil with an orchardgrass companion leads to more persistent birdsfoot trefoil varieties for use in grass mixtures compared with birdsfoot trefoil bred without a...

Understanding Species Traits and Biodiversity Indices to Solve Problems Associated with Legume Persistence in Cropping Systems

“…Previously, it has been shown that legumes persist less in mixtures because of exploitation by grasses for light and fixed N as earlier mentioned [10]. This scenario is evident from changes in morphological traits [28] as well as resource allocation [29]. Both species traits and management practices influencing forage monocrop persistence have been described in detail by Bouselinck et al [26].…”

Plant breeding for resilient pastures

“…When measuring crude protein concentration, there was no genetic correlation between the two systems (r= -0.13, not significant). Similarly, Riday & Brummer (2014) demonstrated that selecting birdsfoot trefoil (Lotus corniculatus) with a cocksfoot companion leads to more persistent birdsfoot trefoil varieties for use in grass mixtures than birdsfoot trefoil bred without a grass companion.…”

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

“…Forages are frequently grown in grass-legume mixtures ( Riday and Brummer, 2014 ). In alfalfa ( Medicago sativa ), the most widely grown forage crop, planting practices vary by region, with mixtures more common in the northeast and upper Midwestern United States ( Undersander et al, 2011 ).…”

“…In alfalfa ( Medicago sativa ), the most widely grown forage crop, planting practices vary by region, with mixtures more common in the northeast and upper Midwestern United States ( Undersander et al, 2011 ). White clover ( Trifolium repens ) is grown almost exclusively in mixed stands ( Riday and Brummer, 2014 ). In general, legumes are weaker competitors compared to grasses, with the exception of alfalfa which often dominates mixtures when included as the legume component ( Haynes, 1980 ; Zannone et al, 1986 ; Jones et al, 1989 ; Annicchiarico and Proietti, 2010 ; Brophy et al, 2017 ; Maamouri et al, 2017 ).…”

“…Among forages, white clover-grass mixtures have a longer history of research and breeding, since white clover is grown predominantly in mixtures ( Dijkstra and De Vos, 1972 ; Hill, 1990 ). Other forage legumes, including alfalfa, red clover ( Trifolium pratense ), and birdsfoot trefoil ( Lotus corniculatus ) have received less attention in terms of breeding specifically for mixture systems ( Riday and Brummer, 2014 ).…”