| Soybeans | Forages
| Cereals | Dry
Edible Beans |
Table of Contents
Cereal crops do not respond significantly to tillage.
Research comparing the yield response of winter wheat to various
tillage options demonstrated no yield advantage among moldboard
plowing, minimum tillage and no-till systems Table
4-1, Winter Wheat Yield Response to Tillage Systems. While yields
are not affected greatly by tillage systems, good seed-to-soil contact
and soil moisture for germination are essential.
The selection of a tillage system will impact other
components in the system. The tillage method chosen must fit with
factors such as fertility, insect pressure, disease incidence and
weed control for producing high-yielding, profitable crops. Risks
associated with more intensive tillage in winter crops include greater
frost-heaving potential and increased risk of snow mould. Erosion
is a concern with tillage in all crops.
There are several options for seeding cereals that include:
Most winter wheat is grown using a no-till system. No-till yields are often equal to yields obtained with conventional tillage. No-till drills can follow the combine in the same field, which advances seeding date, therefore increasing yields. No-till planted winter cereals are better able to resist frost heaving, as the plant anchors itself in firmer soil.
1 Average yields vary because comparisons come from a range of sites.
The success of a no-till system requires consideration of fertilizer
management, drill capability and weed control. No-till cereals show
more response to seed-placed starter fertilizer, especially phosphorus,
compared to conventional tilled crops.
No-till crops grown without starter fertilizer often develop "corn
row syndrome" symptoms. Wheat plants growing over old corn
rows will be significantly taller and more vigorous than plants
growing between the rows. This is primarily due to higher phosphorus
availability from the corn starter fertilizer band, even though
the corn crop was grown 2 or 3 years prior to the wheat crop. Fields
receiving 58 kg/ha of supplemental P2O5 (100
lb/acre MAP) overcame the variability in wheat growth. The addition
of low rates of P with a liquid starter reduced the corn row effect
but did not eliminate it. (Table 4-2, Corn Row
Syndrome, and Plate 23. Winter wheat
is one of the most responsive crops to phosphorus fertilization.
This is shown in Table 4-3, Yield Response to
Fertilizer Rate, which summarizes 4 years of comparisons on
fields with a large range of fertility levels.
Seed-to-soil contact is critical for moisture uptake. No-till drills
must be able to cut through residue and penetrate into hard soil
to accurately place seed. Adding seed-firming wheels or plastic
"hockey stick" seed firmers will help press the seed into
the bottom of the seed trench, which will help increase seed-to-soil
contact and improve seed depth uniformity.
Weed control is critical in no-till systems. A burndown before
planting ensures control of dandelions and other winter annual weeds
and should be a standard practice. See OMAFRA
Publication 75, Guide to Weed Control, for burndown recommendations.
To reduce disease incidence, use a fungicide seed treatment. For
further information on seed treatments, see the OMAFRA
Publication 812, Field Crop Protection Guide.
In dry soils, the addition or use of tillage coulters may show
some benefit in a no-till system. Slight loosening of dry, hard
soils allows for better, more rapid root development and growth.
In a wet fall season, light tillage may speed soil drying and allow
for planting in better conditions. These limited tillage methods
should be used when soil conditions dictate.
Cereals have been grown for generations using the plow, disc and
cultivator for seedbed preparation. Many spring cereals are still
grown using conventional tillage. While this system works well,
erosion concerns, fuel costs, labour costs and limited yield response
to tillage continue to shift acres into reduced tillage. The guidelines
regarding seed-to-soil contact, planting into moisture and seeding
depth accuracy are consistent with the no-till section. The tillage
operations replace the herbicide burndown.
Seeding spring cereals into frost can significantly advance seeding
dates and increase yields.
"Frost seeding" refers to no-till seeding cereals into a light frost in early spring. After the snow has melted, and the frost is out of the ground, there are often several cold nights with below-zero temperatures. Seeding into this light frost is possible, as the frost will support the tractor and avoid compaction or rutting. It is not essential to close the seed trench when frost seeding, as the soil will naturally fall in and cover the seed as the frost comes out of the ground. Simply set no-till equipment to make a shallow (2.5-cm or 1-in.) seed trench and firm the seed into the bottom of the trench.
The window of opportunity for this method of seeding is short.
Do not attempt this method of seeding when air temperatures
drop below -8°C. The ground will be frozen hard enough
to damage the no-till equipment, and seed will be left on the soil
surface with poor results. Best results are generally as the frost
is just beginning to firm the soil, about -3 to -4°C, often
near midnight. It is critical to stop as soon as frost begins to
soften in the morning sun, as thawed soil will stick and plug equipment
in as little as 15 m (50 ft.) of travel.
While this narrow window of opportunity may not occur every year, the increase in yield from early planting using this technique can be as much as 25%. Table 4-4, Frost Seeding vs. Seeding Into Dry Soil of Spring Cereals, shows the yield and quality advantage of frost seeding. Frost seeding of winter cereals in the late fall or early winter has also been successful. However, in these situations it is critical that seed placement is at least 2.5 cm (1 in.) deep, and that yield expectations are realistic.
Aerial seeding is most successful when seed is flown on before
10% of the soybean leaves have dropped. Soybean leaves will cover
seed and help retain moisture for wheat germination.
Results from aerial seeding have been variable. The seed is extremely
vulnerable to slug damage. Slugs feed on the germ of the kernel,
which can severely thin or destroy the stand, particularly on headlands.
The seed will appear to still be on the surface, as if waiting to
germinate, but on closer examination, the damage to the kernel becomes
evident. Reseeding of headlands after soybean harvest can help overcome
The shallow root system that develops from aerial-seeded wheat is more prone to heaving injury and wind damage Depth of Seeding. In the spring, wheat plants will be attached to the soil by only one hair root. If this hair root breaks as plants twist with the wind, the plant dies.
1 Each treatment represents an average of three different populations; 0.8, 1.2 and 1.6 million seeds/acre for oat and 1.2, 1.6 and 2.0 millions seeds/acre for spring wheat.
With these inherent risks, yields from aerial-seeded wheat are
often 10% lower than from drilled wheat, (limited on-farm trial
data). Therefore, aerial seeding is not a standard practice. Where
aerial seeding is attempted, increase the seeding rate to 5.0 million
seeds/ha (2 million seeds/acre) to compensate for stand loss.
Broadcast seeding can greatly speed the planting process. It is
important to get good seed-to-soil contact and a uniform seeding
rate across the width of the spread pattern and between passes of
Using airflow units is an effective way to achieve the uniform
spread pattern. Till fields at a shallow depth (7.5-cm or 3-in.)
twice, at right angles, then pack the crop to help prevent streaking
in the seeding pattern and improve seed-to-soil contact.
This method produces an inconsistent seeding depth. Variable maturity
and a 5%-10% reduction in yield are often the result. Increasing
seeding rates by 10% will help compensate for the potential variability
of broadcast seeding.
For more information:
Toll Free: 1-877-424-1300