TITLE:
Nitrogen Fertilization and Inoculation Effects on Dry Bean
AUTHORS:
Ryan Buetow, Grant H. Mehring, Hans Kandel, Burton Johnson, Juan M. Osorno
KEYWORDS:
Dry Bean, Rhizobacteria, Nitrogen, Legume
JOURNAL NAME:
Agricultural Sciences,
Vol.8 No.10,
October
11,
2017
ABSTRACT: Dry bean (Phaseolus vulgaris L.) has the ability to form symbiotic relationships
with N2-fixing bacteria. The research objectives were to evaluate yield
and growth differences between dry bean cultivars from black, navy, and pinto
market classes, with different N management combinations utilizing urea
fertilizer, and two rhizobacteria inoculants. Research was conducted near Park
River and Prosper, ND, during 2010, 2012, 2013. The experiment was a RCBD
3 × 2 × 3 factorial with four replicates with three dry bean cultivars, two N
fertility levels, and two rhizobacteria inoculum sources plus a non-inoculated
treatment. The pinto cultivar was also evaluated in 2014. Results showed significant
cultivar main effect differences for nodules per plant, vigor, height,
and 1000 seed weight. The pinto cultivar had significantly more nodules per
root (19) compared with the black (13) and navy cultivars (9). There were not
significant differences between inoculant treatments. The fertilizer main effect
indicated significant differences for vigor and 1000 seed weight. No significant
interactions were detected among factors. Addition of 56 kg N ha-1 resulted in
more vigorous plants, but had no effect on seed yield, and reduced 1000 seed
weight at harvest at Park River in 2013. Root nodule number was higher with
the inoculant treatments with 16.2 and 15.8 nodules per plant compared to the
non-inoculated treatment with 10.7 nodules per plant at Park River in 2013. The
pinto variety Lariat with an application of 56 kg ha-1 had visually greener plants
in 2013 and 2014, except Park River in 2013, but SPAD readings were not following
the same trend. Inoculation and application of N fertilizer on dry bean
may not be necessary if rhizobacteria are present and soil N levels are sufficiently
high but future research on rates, timing, and N source and appropriate
strains of Rhizobia inoculant on other pinto varieties is suggested.