HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Zhu, Y. Articles by Montealegre, C. M. Search for Related Content PubMed Articles by Zhu, Y. Articles by Montealegre, C. M. Agricola Articles by Zhu, Y. Articles by Montealegre, C. M.

Inoculation and Nitrogen Affect Herbage and Symbiotic Properties of Annual Medicago Species

Dep. of Agronomy and Plant Genetics Univ. of Minnesota, St. Paul, MN 55108

Carroll P. Vance, Peter H. Graham, Michael P. Russelle, Soil Scientist and C. M. Montealegre

Dep. of Agronomy and Plant Genetics, Univ. of Minnesota, St. Paul, MN 55108
Dep. of Soil, Water, and Climate Univ. of Minnesota, St. Paul, MN 55108
USDA-ARS Univ. of Minnesota, St. Paul, MN 55108
Dep. of Soil, Water, and Climate Univ. of Minnesota, St. Paul, MN 55108

^* Corresponding author (sheaf001{at}maroon.tc.umn.edu)

The interactive effects of Sinorhizobium inoculants and soil N status should affect the N contribution of annual medics (Medicago spp.) in cropping systems. We determined the effect of N and commercial medic inoculum on nodulation, dry matter, and N yield of annual medics and also determined Sinorhizobium strain occupancy in annual medic nodules. Field experiments were conducted on a sandy, mixed Udorthentic Haploboroil and on a fine-loamy, mixed, mesic Typic Hapludalf. More than 75% of annual medic plants (except M. rugosa Desr.) were nodulated in the absence of commercial inoculum, and nodulation was due in part to a Sinorhizobium strain that frequently nodulates alfalfa (Medicago sativa L.). Among the five strains in the commercial medic inoculum, 102G3 and 102A13 had the greatest nodule occupancy. When no N was applied, inoculation improved the percentage of plants nodulated and nodule mass only in M. rugosa, compared with no inoculation, but inoculation increased herbage yields of spring-seeded M. truncatula Gaertn. cv. Sephi, M. polymorpha L., and M. rugosa by about 60%, compared with no inoculation. Nitrogen addition reduced the nodule mass of all species when inoculum was applied, and N addition increased only the herbage dry matter yield of spring-seeded M. scutellata (L.) Mill. when inoculum was applied. This suggests that a more effective inoculum could be developed for M. scutellata so that N would not limit herbage growth. Annual medics fixed from 40 to 80 kg N ha^–1 if spring-seeded and grown for 60. d, and from 20 to 50 kg N ha^–1 if summer-seeded and grown for 43 d.

Received for publication November 1, 1997.

This article has been cited by other articles:

				P. Seguin, C. C. Sheaffer, N. J. Ehlke, M. P. Russelle, and P. H. Graham Nitrogen Fertilization and Rhizobial Inoculation Effects on Kura Clover Growth Agron. J., November 1, 2001; 93(6): 1262 - 1268. [Abstract] [Full Text] [PDF]