INTERCROPPING ANNUAL MEDIC WITH CONVENTIONAL HEIGHT AND SEMIDWARF BARLEY GROWN FOR GRAIN

Citation
Jm. Moynihan et al., INTERCROPPING ANNUAL MEDIC WITH CONVENTIONAL HEIGHT AND SEMIDWARF BARLEY GROWN FOR GRAIN, Agronomy journal, 88(5), 1996, pp. 823-828
Citations number
26
Categorie Soggetti
Agriculture
Journal title
ISSN journal
00021962
Volume
88
Issue
5
Year of publication
1996
Pages
823 - 828
Database
ISI
SICI code
0002-1962(1996)88:5<823:IAMWCH>2.0.ZU;2-M
Abstract
Interseeding annual legumes with grain crops has been proposed as a cr opping strategy to enhance ground cover, thereby reducing weed competi tion, suppressing soil erosion, and providing N for use by subsequent crops. The potential of annual medics (Medicago spp.) for intercroppin g in small-grain cropping systems has not been adequately assessed for the north-central United States. Our objective was to evaluate a spri ng barley (Hordeum vulgare L.)-annual medic intercrop system for barle y grain yield, fall biomass production, suppression of fall weeds, and quantity of N available for incorporation into the soil. Field experi ments were conducted in four Minnesota environments (Becker, Morris, R osemount, and St. Paul). Conventional height 'Robust' and semidwarf 'R oyal' barley were intercropped with each of three medic species ['Geor ge' black medic (M. lupulina L.), 'Mogul' barrel medic (M. truncatula Gaertn.) and 'Santiago' burr medic (M. polymorpha L.)]. Intercropping with medics reduced barley yields by an average of 6% at Rosemount, 30 % at St. Paul, and 76% at Becker, compared with monoculture barley fer tilized with N. Medics increased yields by 9% at Morris. Intercropping with medic reduced fall weed mass by an average of 65% across environ ments, compared with the fertilized Royal monoculture. Nitrogen availa ble for incorporation from the barley-medic intercrops ranged from 66 to 140 kg ha(-1) over the environments, whereas N available for incorp oration from fertilized barley monoculture ranged from 22 to 80 kg ha( -1) We conclude that the prospects for successfully intercropping with annual medic in a barley grain production system are mixed and depend in part on the medic species used and barley stature. A wider array o f medic types should be evaluated for their suitability in intercroppi ng with small grains.