Alfalfa and Reed Canarygrass
Response to Midsummer Manure Application
JoAnn F. S. Lamb,* Michael P. Russelle, and
Michael A. Schmitt
Abstract
Perennial forages like alfalfa (Medicago
sativa L.) or various perennial grasses, which
are cut several times during the growing season, could
provide an alternative land base and time management
strategy for manure applications. Our objectives were
to evaluate the response of two forage species to
increasing rates of swine manure slurry applied in
midsummer and to compare commercially available alfalfa
cultivars for tolerance to swine manure applied during
the growing season. The first experiment, hereafter
referred to as the rate experiment, included four
entries, two N2–fixing (UMN 3097
and ‘Agate’) and one non-N2–fixing
(Ineffective Agate) alfalfa and reed canarygrass (Phalaris
arundinacea L.), grown at two locations in Minnesota.
Liquid swine manure was applied at five rates (0,
23.4, 32.7, 42.1, and 93.6 kL ha-1) within
4 d after the second forage harvest in July 1998 and
1999. In the second experiment, hereafter referred
to as the cultivar study, six alfalfa cultivars, Magnagraze,
5312, Rushmore, Wintergreen, Winterstar, and WL 325
HQ, were evaluated for response to manures applied
at three rates (0, 37.4, and 93.6 kL ha-1)
as described above. Manure slurry containing less
than about 3300 kg ha-1 organic solids
applied 4 d after cutting in July improved reed canarygrass
yields and had no effect or slightly improved yields
of normalN2–fixing alfalfa. Ineffective Agate
yields improved with increasing manure rates, but
insufficient N was applied to keep this entry productive.
Alfalfa cultivars did not differ in yield response
to manure applications. Organic solids in the manure
slurries at one of the locations compromised forage
yields and stand scores at the highest application
rate by completely coating and smothering the plants.
Results emphasized the importance of manure testing
to reduce adverse effects on alfalfa and reed canarygrass
yields.
Keywords:Medicago
sativa L., Phalaris arundinacea L.,
Alfalfa,Reed Canarygrass,Organis
farming.
