Tm. Reinbott et Dg. Blevins, MULTIYEAR USE OF KILLED STRIPS FOR FORAGE AND GRAIN-SORGHUM PRODUCTION IN A TALL FESCUE PASTURE, Journal of production agriculture, 8(3), 1995, pp. 354-359
Tall fescue (Festuca arundinacea Schreb.) is an excellent perennial gr
ass for spring and fall forage production and for erosion control on s
loping land. Tall fescue forage production is poor during the summer,
however. Our objective was to improve pasture productivity without inc
reasing erodibility by planting a sorghum x sudan hybrid [Sorghum bico
lor (L.) Moench x Sorghum bicolor L. Moench] (S x S) or grain sorghum
[Sorghum bicolor (L.) Moench] (GS) in 12 in. killed strips of tall fes
cue and to determine if strips could be used in subsequent pars withou
t additional herbicide treatment. Forage from a block of tall fescue w
as harvested in May 1990, and plants were allowed to regrow for 1 wk b
efore application of glyphosate in 12 in. strips on 30 in. centers at
two rates of 1.2 and 0.6 lb ai/acre (strip-kill). For control treatmen
ts, the entire tall fescue sod was killed (complete-kill) or tall fesc
ue was not sprayed in order to measure forage production from the gras
s monoculture. The SxS (cv. FFR 201) was planted into strip-kill and c
omplete-kill plots 1 wk after glyphosate treatment in 1990 and again i
n 1991 and 1992 without additional glyphosate treatment. In May 1991,
GS (cv. MFA GS-10) was planted into strip-kill and complete-kill plots
and these! strips were used again in 1992. Tall fescue was successful
ly killed with a single application of each rate of glyphosate in the
strip-kill and complete-kill systems. There was little difference in S
xS dry matter yield or GS grain yield between glyphosate treatments, D
ry matter yield of S x S in strip-kill plots decreased each year after
initial treatment in 1990, probably a result of increased competition
from tall fescue encroachment into the killed strips. Dry matter yiel
d of S x S in strip-kill plots was 16, 49, and 52% less than that of t
he complete-kid plots in 1990, 1991, and 1992, respectively. Tall fesc
ue yield in strip-kill plots was only slightly less than that of tall
fescue (monoculture) control plots, Total forage yield (S x S plus tal
l fescue) in the strip-kill plots was 3.49, 2.39, and 1.63 tons/acre g
reater than that of the tall fescue (monoculture) control in 1990, 199
1, and 1992, respectively, Grain sorghum yield in strip-kill plots was
25 bu/acre less than that in complete-kill plots in 1991 and 53 bu/ac
re less than that in complete-kill plots in 1991, Planting S x S into
the same strip-kill plots is feasible for 3 yr, however for GS to be s
uccessful in a strip-kill system, tall fescue strips must be killed an
nually.