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Winter Small Grains Cover Crop Following Potatoes
R.L. Dovel, K.A. Rykbost, G. Chilcote, and J. Rainey 1
INTRODUCTION
A major obstacle to sustained agriculture in the Klamath Basin is soil
loss due to wind erosion. Light soils and high spring winds provide conditions for substantial soil loss in this region. To ensure the continued
productivity of highly erodible soils, federal farm programs are requiring
greater erosion control on these soils. The local SCS office has determined
that residue covering 33 percent of the soil surface will provide sufficient
cover to prevent substantial soil loss. The amount of crop residue left
following potato harvest is minimal and vines are sometimes burned to reduce
over-wintering pathogens. A cover crop is needed to protect the soil
through the winter and especially during the spring following potato harvest. The highest erosive wind energy is received in April in the Klamath
Basin.
A small-grain cover crop is one of the most effective methods for
The cost of erosion control could be minimized if the
erosion control.
cover crop could also produce a marketable grain or forage crop. While
small grains are, an important component of cropping systems in the Klamath
Basin, most of the grain planted is sown in the spring. This project was
conducted to identify species and varieties of winter grains that are
adapted to this region. Screening should include both forage and grain
yield as well as the ability to provide adequate soil protection.
PROCEDURES
A trial consisting of seven wheat varieties, seven barley varieties, two
oat varieties, and one variety each of cereal rye and triticale was planted
at the KES on October 15, 1987. Plots were 5 feet wide and 40 feet long.
Seed was planted 1 inch deep with rows 6 inches apart at a rate of 30 seeds
per square foot, which corresponds to roughly 100 lbs/A for wheat, barley,
and triticale and 85 lbs/A for rye and oats. Fertilizer was banded in at
planting at a rate of 50 lbs N, 60 lbs P205, and 44 lbs S/A. No chemical
Seed was sown into fairly dry soil; however,
weed treatment was applied. seed did germinate and emerge. Due to low moisture availability, growth
was slow until rains on November 9 provided adequate moisture for rapid
growth.
/ Assistant Professor, Superintendent/Associate Professor, Research
Technician, Experimental Biology Technician, respectively
Klamath Experiment Station.
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Three harvests were made: one on May 10, to monitor biomass accumulation
and ground cover for the prevention of wind erosion; one on June 12 when
most of the cultivars were in the boot stage, to assess forage production;
and one after complete grain fill to measure grain production.
RESULTS
No differences were seen between varieties or species in emergence and
fall growth.
All varieties reached the four-leaf stage before snow cover
stopped growth.
Adequately monitoring early spring growth was impossible
due to grazing by geese.
By May 10 effects of the geese damage were no
longer seen and plants were harvested. Cereal rye was clearly the highest
biomass producer, more than doubling the average yield of all barley
varieties and more than tripling the average wheat yield. No real differences among barley varieties for early spring biomass production were evident.
Some varieties of wheat were definitely superior to others in early spring
biomass production. Hill '81 and Nugains were the highest wheat biomass
producers. Cereal rye also dominated total forage yield as assessed by the
harvest on June 12. It yielded 4.4 tons/A compared to an average of 3, 2.5,
and 2.5 tons/A for barley, wheat, and oats, respectively (Table 1). The
forage yield of triticale was roughly equivalent to the barley varieties
included in this study.
The highest average grain yield was obtained by barley. Hesk and Boyer
significantly outyielded all other barley varieties. Similarly, Hill '81,
outyielded other wheat varieties (Table 1).
CONCLUSIONS
In a mild fall and winter, cover crops planted on October 15, following
potato harvest, achieved sufficient fall development to provide late fall
and early spring erosion protection. Cereal rye produced the greatest
biomass and largest amount of early ground cover and is the species most
likely to provide protection against wind erosion under adverse conditions.
Low grain yields and low price for cereal rye make it a less desirable cover
crop alternative. Maury winter barley produced the highest early spring
biomass and forage yield and also produced over two tons of grain. Maury
provided the option of harvest for either forage or grain while providing
ground cover in the early spring. The use of winter wheats studied as
ground cover/cash crops does not look as promising as barley due to lower
ground cover, hay production, and grain potential.
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Table 1. 1987-1988 Winter Small Grains Cover Crop Trial. Observations
of forage and grain production of fall seeded winter grains
following potatoes, planted on October 15,at the Klamath
Experiment Station.
'
Barley
1)
2)
3)
4)
5)
6)
7)
FORAGE PRODUCTION
May 10
June 12
tons/A
GRAIN YIELD
lbs/A
lbs/bu
Henry
Maury
Sussex
Wysor
Hesk
Scio
Boyer
MEAN
0.8
0.9
0.6
0.8
0.8
0.8
0.8
0.8
2.8
3.8
2.6
3.3
3.2
2.6
2.9
3.0
3821
4155
3287
3873
5674
4162
5267
4320
46.5
46.0
44.0
46.0
46.0
42.0
44.0
45.0
Faro
Fortyfold
Stephens
Yamhill
Weston
Hill '81
Nugains
MEAN
0.4
0.5
0.5
0.2
0.4
0.6
0.7
0.5
2.1
2.8
2.6
1.8
2.6
2.4
2.9
2.5
2514
3502
2834
2175
3453
4292
2655
3061
52.0
58.5
54.5
50.0
61.5
57.5
60.5
56.0
Grey Winter
Walken
MEAN
0.5
0.6
0.6
2.7
2.4
2.5
1378
1341
1360
32.0
27.0
29.5
Triticale
17) Flora
0.8
2.8
2644
42.0
Rye
18)
1.7
4.4
3160
56.5
0.7
29.5
0.3
2.8
30.6
1.2
3344
21.1
1003
48.0
5.8
4.0
Wheat
8)
9)
10)
11)
12)
13)
14)
Oats
15)
16)
Rheidol
OVERALL MEAN
CV
LSD(0.05)