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 Trimble, M. W. Articles by Sheafter, C. C. Search for Related Content PubMed Articles by Trimble, M. W. Articles by Sheafter, C. C. Agricola Articles by Trimble, M. W. Articles by Sheafter, C. C.

Forage Yield and Nitrogen Partitioning Responses of Alfalfa to Two Cutting Regimes and Three Soil Nitrogen Regimes¹

Plant breeders need to thoughtfully select appropriate crop management systems for the evaluation of alfalfa (Medicago sativa L.) populations. The objective of this study was to determine if genotype x treatment interactions were associated with frequency of cutting and soil N concentrations. Twenty-eight alfalfa populations representing four winterhardy germplasm sources were evaluated in six treatments using hill plots at three Minnesota locations. The six treatments consisted of three soil N regimes, referred to as high, ambient, and low (approximately 200, 20, and 10 kg NO₃/ha, respectively) and each tested over three and four-cut regimes. The experimental design was a randomized complete block with a split-plot treatment arrangement. Whole plots were the six treatments Subplots were the 28 populations. Measurements included herbage, crown, and root yield; plant number per plot; winter injury; nodule mass; root disease; tap root size; and N concentratin in the herbage, crowns, and and roots. The high soil N regime reduced nodulation and increased herbage yield during the establishment year, indicating that plant available N was limiting herbage production in the ambient N and low N regimes. The high soil N increased N concentration in the herbage, crowns and roots, but did not change the N proportion in those palnt parts. The germplasm x soil N regime interaction was not significantly for herbage yield, but it was significant for total root and lateral root yield. Cutting regime affected all measurements except tap root size. Significant germplasm x cutting regime interactions were observed for herbage and root yield, winter injury, and tap root size. Germplasms differed in their ability to partition biomass to herbage and to roots. The results suggested that crop management systems must be chosen carefully because they can affect the rank in performance among alfalfa populations for many agronomic traits.

Key Words: Medicago sativa L. • Genotype x environment • Alfalfa breeding • Alfalfa evaluation • Nodulation • Source-sink relations

² Formerly graduate research assistant, Dep. of Agronomy and Plant Genetics, Univ. of Minnesota (currently research station manager, Pioneer Hi-bred International Inc., Dep. of Corn Breeding, Box 486, Princeton, IN 47670); research geneticist, USDA-ARS; research geneticist, USDA-ARS; research plant physiologist, USDA-ARS; and professor, Dep. of Agronomy and Plant Genetics, Univ. of Minnesota, St. Paul, MN 55108.

Received for publication October 30, 1986.

This article has been cited by other articles:

				D. D. Redfearn, B. C. Venuto, and W.D. Pitman Nutritive Value Responses of Rhizoma Peanut to Nitrogen and Harvest Frequency Agron. J., January 1, 2001; 93(1): 107 - 112. [Abstract] [Full Text]