Establishment and Persistence of Legumes Interseeded into Switchgrass

Abstract

Little information is available for renovation of established switch‐grass (Panicum virgatum L.) with cool‐season forage legumes. Field experiments were conducted to determine seeding success, persistence, and impact on grass when 10 forage legumes and a legume mixture were no‐till interseeded into established ‘Cave‐in‐Rock’ switchgrass near Ames, IA. Legumes interseeded in early April 1991 and 1992 were biennial ‘Polara’ white‐flowered sweetclover (Melilotus alba Medik.) and ‘Madrid’ yellow‐flowered sweetclover (‘Melilotus officinalis’ Lam.), ‘Norcen’ and ‘Fergus’ birdsfoot trefoil (Lotus corniculatus L.), ‘Apollo Supreme’ and ‘Alfagraze’ alfalfa (‘Medicago saliva’ L.), Mammoth and ‘Redland II’ red clover (Trifolium pratense L.), ‘Emerald’ crownvetch (Coronilla varia L.), common hairy vetch (Vicia villosa Roth.), and a 50:50 mixture of Norcen trefoil and medium red clover. Legume renovation was compared with grass fertilized with N at 0, 60, 120, and 240 kg ha−1. Excellent legume establishment was observed in June, about 2.5 mo after interseedings, with mean legume plant density of 195 and 163 plants m−2 for 1991 and 1992 seedings, respectively. Both alfalfa cultivars and hairy vetch had highest percentage establishment. Average legume persistence to June of the second year was nearly 50% for 1991 and 30% for 1992 seedings (less in 1992 because of greater winter losses). Grass stem density during the establishment year was not affected by legume renovation. Decline in grass stems during the second year was greatest for trefoil and the trefoil‐red clover mixture, and intermediate for alfalfa and red clover, with minimal to no effect for the sweetclovers, crownvetch, and hairy vetch. Hence, legumes can be successfully established into switchgrass and can be maintained into the second year

A quantitative review comparing the yield of switchgrass in monocultures and mixtures in relation to climate and management factors

“…Switchgrass yield was significantly higher in the mixtures with legumes present compared with mixtures without legumes (Table 1). This supports the findings of Blanchet et al (1995) and that legumes benefit the grass in a grass-legume mixture if the legumes achieve an adequate stand density. Total yield of the mixtures was significantly higher when legumes were present (Table 1) and was not significantly different from monoculture yield, suggesting legumes can be incorporated into established switchgrass without negatively impacting total dry matter yields.…”

QUALITY CHARACTERISTICS OF THE MIXTURES OF SOME WARM SEASON PERENNIAL GRASSES WITH ALFALFA (Medicago sativa L.) UNDER IRRIGATED CONDITIONS OF CUKUROVA

“…Some researchers reported that warmseason forage crops could be succesfully grown in mixtures with legumes (Aganoglu 1985;Blanchet et al, 1995;Larbi et al, 1995;Gettle et al, 1996;Tessema and Baars 2006).…”

Forage Yield and Botanical Composition of Mixtures of Some Perennial Warm Season Grasses with Alfalfa (Medicago sativa L.) Under Mediterranean Condi

“…Some researcher reported that growing warm-season grasses with legumes resulted in higher dry matter yields than pure sowings (Aganoglu 1985;Blanchet et al, 1995;Larbi et al, 1995;Gettle et al, 1996;Tessema and Baars 2006 ).…”