Article
Dinitrogen fixation and transfer in legume‐crested wheatgrass mixtures on semiarid rangelands
Arid Soil Research and Rehabilitation
(1993)
Abstract
The inclusion of legumes in grass pastures often increases grass forage quality due to the transfer of fixed N from legumes to associated grasses. This benefit may be important for crested wheatgrass [Agropyron cristatum L. Gaertn. and A. desertorum Fisch. ex (Link) Schult.] growing on western rangelands where productivity is frequently N‐limited. To evaluate this benefit, alfalfa (Medicago sativa L.) or annual sweetclover(Melilotus alba Medik. var. annua Coe) was interplanted with Hycrest crested wheatgrass [Agropyron cristatum L. Gaertn. × A. desertorum Fisch. ex (Link) Schult.] in single species rows on 15N‐labeled Aquic Argiustoll and Calcic Argixeroll soils in Cache Valley and Tintic Valley, Utah, respectively. Crested wheatgrass herbage had significantly lower 15N concentrations when grown near alfalfa than in monoculture, and alfalfa near crested wheatgrass had significantly lower l5N concentrations than monoculture alfalfa. Sweetclover herbage had significantly lower 15N concentrations when grown near crested wheatgrass than when grown in monocultures. Analysis of crested wheatgrass herbage showed significantly lower 15N concentrations near sweetclover than in monoculture. Isotope dilution calculations indicated that crested wheatgrass derived up to 32 and 29% of its N from alfalfa and sweetclover, respectively, depending on site, year, and grass‐legume ratio. Nitrogen transfer occurred over a distance of at least 25 cm and increased as the proportion of alfalfa or sweetclover to crested wheatgrass increased. Alfalfa and sweetclover apparently are capable of transferring significant amounts of fixed N to crested wheatgrass when growing in mixture on Great Basin rangelands.
Disciplines
Publication Date
1993
DOI
https://doi.org/10.1080/15324989309381330
Citation Information
Christopher A. Call. "Dinitrogen fixation and transfer in legume‐crested wheatgrass mixtures on semiarid rangelands" Arid Soil Research and Rehabilitation Vol. 7 Iss. 1 (1993) p. 1 - 13 Available at: http://works.bepress.com/christopher_call/63/