EFFECTS OF THREE TILLAGE SYSTEMS ON WHEAT YIELD AND DOUBLE CROP SOYBEAN YIELD

1
EFFECTS OF THREE TILLAGE SYSTEMS ON WHEAT YIELD
AND DOUBLE CROP SOYBEAN YIELD

• Estienne,C.E. 1
• 1 ANR Extension Agent, Greensville County/City of
  Emporia, VA 23847

ABSTRACT Increasingly southeast Virginia
farmers are limiting tillage to build up soil
organic matter and decrease erosion. Slagle, a
fine, sandy loam soil common in this area, is an
excellent productive soil. However these sandy
soils are prone to developing hardpans from
discing and vehicular traffic during the growing
and harvest season. A Slagle soil field was
tested using a penetrometer and found to have a
uniform hardpan at a 6-8 inch depth. Following
cotton harvest, stalks were mowed and three
tillage treatments were employed. Each treatment
was replicated four times in a randomized
complete block design. Treatment 1 (TRT 1)
consisted of traditional discing, followed by
drilling wheat on 7 inch rows. Treat 2 (TRT 2)
was no-till drilled wheat with no additional
tillage. Treat 3 (TRT 3) included ripping 36
inch on center (between previously ripped cotton
rows) followed by no-till drilled wheat on 7
inch rows. Wheat was harvested and yield, test
weight and moisture were determined. Soybeans
were no-till drilled in 7-inch rows in the same
treatment plots as the wheat. At harvest soybean
yield and moisture were measured. There was a
significant wheat yield increase for TRT 3 when
compared to TRT 1, and TRT 2. There was no
difference between TRT 1 and TRT 2. TRT 3 also
produced a significant yield increase in
double-cropped soybeans when compared to TRT 1.
SOYBEAN YIELDS Treatment with different
letters indicate a statistically significant
difference in yield (Plt .05)
METHODS Following cotton harvest 12 plots were
laid out on a Slagle fine sandy loam field
determined to have a uniform hardpan at a 6-8
inch depth. Three treatments were replicated
four times across the field in 30 foot by
approximately 500 foot plots. The first
treatment consisted of discing the plots. There
was no tillage prior to drilling wheat in
Treatment 2. Treatment 3 consisted of ripping to
a depth of 12 inches, 36 inch on center between
cotton rows ripped at planting. All three
treatments were followed by drilling wheat in 7.5
inch rows at a1.5 inch depth with 22 seeds per
foot. Fertilization and pest management were the
same across all treatments. A 22 foot swath of
wheat was harvested from the center of each plot,
weighed, moisture tested and yield per acre
calculated. Soybeans were no till drilled into
wheat stubble. Once again, seeding rate,
fertilization and pest management were the same
across treatments. Soybeans were harvested from
the center of each plot, weighed, moisture
tested, and yield determined. A significant
treatment effect was determined for mean yields
of wheat and soybeans using analysis of variance
(SAS Cary NC) followed by multiple comparisons
between means.
TREATMENT YIELD (BU/ACRE)
1 44ab
2 42.75a
3 44.45b
Wheat was planted November 9, 2005
WHEAT YIELDS Treatments with
different letters indicate a statistically
significant difference in yield (P lt .05).
TREATMENT YIELD (BU/ACRE)
1 99.87a
2 98.33a
3 104.08b
Soybean Harvest December 8, 2006
Discing prior to drilling wheat
CONCLUSION Deep tillage significantly increased
wheat yield when compared to no tillage and
traditional discing prior to drilling. Soybean
yields were also significantly greater in deep
tillage plots when compared to no till drilling.
However there was no difference in soybean yields
between deep tillage and discing prior to
drilling wheat.
OBJECTIVE The objective of this research
trial was to determine the effect of deep
tillage, compared to no tillage and traditional
discing and planting on wheat yields and
subsequent double crop soybean yields in a field
determined to have a hardpan.
Ripping prior to drilling wheat
ACKNOWLEDGEMENTS The author expresses her
appreciation to Wes Alexander for his help in
conducting this trial, Dr Wade Thomason for
advice on experimental design and running
statistical analysis, Clifton Dixon for tillage
equipment Glen Chappell for his assistance at
harvest, and Bruce and Larry Whitley for their
cooperation.
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Wheat Harvest June 19, 2006
Drilling wheat