1. Skip Row Corn Planting Techniques with Cover Crops for
Sustainable Grazing
Hoormann, *R.1; Ellis, C.2
1Agronomy Specialist, University of Missouri Extension, Montgomery City, MO, 63361
2Environomental Resource Engineer, University of Missouri Extension, Troy, MO, 63379
Abstract
Broadcasting cover crops into standing corn has the potential to increase forage dry matter production, increase total forage quality available for grazing and increase livestock grazing capacity. However, the dense foliage canopy of traditional
high plant population systems limits light penetration necessary for cover crop seed germination until normal crop senescence at the R-5 stage of growth. Five replications of a randomized complete block design comparing the local standard
corn population to a reduced planting population and skip-row planting techniques was used to remove canopy density as a restriction of light penetration allowing for earlier cover crop seed germination and thereby maximizing the number
of growing days prior to fall killing temperatures. Two years of data collection to date of a three year study indicates increased light penetration by varying corn populations does result in significant differences of dry matter yields of corn grain
yield, cover crops dry matter yield and weed dry matter yield. First year results include significant suppression of corn yields and cover crops in skip-row treatments due to late season weed pressure. Second year results using herbicides
eliminated weeds resulting in significantly greater cover crop dry matter yield. A third year of study is planned.
Background/Problem/Solution 2011 Results
Greater profitability per acre and reduced business risk by getting more forage out of existing acreage is critical to In 2011 the corn crop was replanted (June 5) due to weather conditions. The replant in June pushed broadcast
sustainment of livestock production. Intense management of marginally productive soils can result in minimizing input seeding using an electric seeder on a JD 6000 self propelled sprayer at tassel (August 11). The growing season
costs by the addition of cover crop species. By extending the length of time animals can graze forages a reduction in had below normal rainfall resulting in a regional 50% reduction in corn grain yields. However, the plots had no
purchased feed costs will result in a profitable operation even during extreme challenges of high input costs, competition weed growth and cover crop yields were greatly improved over 2010.
for productive acres and livestock price cycles.
6000
2010 Forage/Grain lb/ac
5171
I am in the process of switching from feeding harvested grains to meet feed requirements for feeder lambs, goats and 5000
4705
4899
4484
beef cattle, to a year round grazing system that includes grazing standing corn during the late fall. After the corn ears
4000
are grazed the quality of the remaining corn stover is poor. After I attended a SARE cover crop field day in October of
2009, I was curious about seeding cover crops to enhance the grazing quality of stalks.
lb/ac
2010 Corn
3000
2010 Biomass
2010 CC
Poly. (2010 Corn)
2000 1798 Poly. (2010 Biomass)
1738
MUEXT staff discussed the possibilities of using cover crops in standing corn to get a longer period of high quality
grazing, greater stocking density and develop a system giving a greater return per acre. 1000
679
937
185 251
125 114
0
SS26 SS20 SK26 SK32
Timing of broadcast seeding Aerial seeding is not an economical option for small acreage, but dealer access to high
Population-spacing Treatments
clearance dry box equipment is available and economical when used with dry fertilizer application. If cover crops could
be seeded into standing corn during late June through early July when ground seeding is possible cover crops could 2011 Forage/Grain lb/ac
establish a thick enough stand to achieve fall grazing goals. This would lead to developing a system to that would have
a very positive economic impact on small and large livestock producers in Missouri.
Plot Design
lb/ac
Plot Design
Recommended timing by review of SARE and associated cover crop projects in Illinois, Ohio, Indiana and Michigan, is
to aerial seed at beginning senescence of the corn crop. This maybe too late in the season for cover crops that
winterkill and need to be grazed before deterioration in late December Population-spacing Treatments
There is also limited work on using high clearance ground seeding equipment to get mid season establishment.
2010-11 Forage Yield per Acre
8000
Strip cropping practices with different height crop species in the same field have long been known to allow greater use
of light interception the leaf canopy, resulting in greater yield, particularly on outside rows of the taller crop. Using a corn 7000
variety that takes advantage of addition sunlight and adds more biomass at the same seeding rate makes it possible to
6000
consider early seeding of cover crops into reduced stands or corn.
5000
2010 Biomass
Greater sunlight penetration into a May seeded corn crop can be achieved by skip planting two rows out of a six row
lb./ ac
2010 CC
4000
2011 CC
planter. Measurement of corn grain yield and cover crop (CC) dry matter yield in comparison to full six rows of planting 2010 Corn
as a control will give needed insight and the economic value of the practice. 3000 2011 Corn
2111
2000
1818 1799 1738
1638 1638
A randomized complete block design of four treatments with five replications in a 20 acre field will be used for 1000 937
evaluation. In late June to early July, a mixture of summer annual cover crop species will be seed with nitrogen fertilizer 679
251
into standing corn. Additional winter cover crop species will be broadcast seeded as late in the growing season as corn 0
SS26
185
SS20
125
SK26 SK32
114
height will allow. The two skip-row/population treatments are 26,000 plants/acre and 32,000 plants/acre. The solid stand Population –Spacing Treatment
treatment is 20,000 plants/acre and 26,000 plants/acre. The solid stand 26,000 population is a local standard rate and
will be used as the control for the experiment.
Interim observations and 2012 Plans
2010 Results Data collected to date indicates skip-row planting to manage light for CC growth is not significantly better than solid
stands planting. In addition, weed pressure influenced grain yields in 2010-11, and residual herbicides are useful.
Data collected indicates that greater cover crop seeding rates are necessary to achieve useful CC yields. Mid
In 2010 a late May planting resulted in a June 30 broadcast of dry nitrogen and cover crop seed. While rainfall was season ground broadcast is viable for annual ryegrass, oats, kale and field peas all of which have a broad
favorable during the growing season, there were dry periods that affected cover crop establishment success and germination window. Brassica species will not be seeded in 2012, but crimson clover and grazing turnips will be
allowed late season grass weeds (fall panicum) to dominate cover crop species. Corn grain yields were strongly added.
influenced by the weed biomass