Cereals: Tillage

Excerpt from Agronomy Guide for Field Crops (Chapter 6)

Order OMAFRA Publication 811: Agronomy Guide for Field Crops

Table of Contents

1. Introduction
2. Tillage Options
3. Winter Wheat Yield Response to Tillage Systems 1986-89 - Table 6-1
4. No-Till Seeding
5. Corn Row Syndrome - Table 6-2
6. Yield Response to Fertilizer Rate - Table 6-3
7. Conventional Tillage
8. Frost Seeding of Spring Cereals
9. Aerial Seeding Winter Wheat
10. Broadcast Seeding
11. Updates on Cereals: Tillage
12. Related links...

Introduction

Cereal crops are grown on approximately 25% of the field crop acreage in Ontario. Less management attention is often given to these crops than to corn or soybeans. Historically, cereals have been used as rotation crops and for home-grown feed. With attention to detail and good management, profit from cereal crops can be increased.

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Tillage Options

Cereal crops do not respond significantly to tillage (see Table 6-1, Winter Wheat Yield Response to Tillage Systems 1986-89 and Table 2-3, Tillage System Effects on Crop Yields at Woodstock, Ontario (1996-2000).

Source: Tillage 2000 final report, Aspinall and Kachanoski
¹Average yields vary because comparisons come from a range of sites.

Research comparing the yield response of winter wheat to various tillage options demonstrated that no yield advantage among moldboard plowing, minimum tillage and no-till systems was observed. 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 factors 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.

Seeding options for cereals range from aerial seeding to frost seeding.

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No-Till Seeding

Most winter wheat is now grown using a no-till system. No-till wheat 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 and increases yields. No-till planted winter cereals are better able to resist frost heaving, as the plant anchors itself in firmer soil.

The success of a no-till system requires consideration of fertilizer management, drill capability and weed control. No-till crops show more response to seed-placed starter fertilizer, especially phosphorus, compared to conventional tilled crops.

No-till crops grown without starter fertilizer will often develop the "corn row syndrome" (see the section Fertility and Plate 100).

Plate 100. Corn row syndrome of winter wheat caused by fertilizer or pesticide carryover in the rows of previous crops that affects crop growth.

Wheat plants growing over old corn rows will be significantly taller and more vigorous than plants growing between the rows. This is a result of the higher phosphorous availability from the corn starter fertilizer band, even though the corn crop was grown 2 or 3 years prior to the wheat crop (see Table 6-2, Corn Row Syndrome).

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With 100 lb. MAP (monoammonium phosphate), no difference in visual growth. Ontario data, eight locations, OMAFRA.

Winter wheat is one of the most responsive crops to phosphorous fertilization (see Table 6-3, Yield Response to Fertilizer Rate).

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(Average of 12 sites, 2001)

Seed-to-soil contact is critical for moisture uptake. No-till drills must be able to penetrate into hard soil and through residue to accurately place seed. Add seed-firming wheels or plastic "hockey stick" seed firmers, which will press the seed into the bottom of the seed trench, helping to increase seed-to-soil contact and improving the uniformity of seed depth placement.

Weed control is critical in no-till systems as discussed in the section Weed Control . A burndown before planting ensures control of dandelions and other winter annual weeds and should be a standard practice. Refer to 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, refer to the OMAFRA Publication 812, Field Crop Protection Guide.
(Order OMAFRA Publication 75) (Order OMAFRA Publication 812)

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. It is important to take the necessary steps to create a proper seedbed and get the crop seeded as quickly as possible.

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Conventional Tillage

Cereals have been grown for generations using the plow, disc and cultivator for seedbed preparation. Most spring cereals are still grown using conventional tillage. While this system works well, the potential erosion concerns and lack of yield response to tillage have shifted acreage towards a reduction in 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.

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Frost Seeding of Spring Cereals

Seeding spring cereals into frost is a relatively new technique in Ontario that can significantly advance seeding dates and potentially increase yields. This strategy has been used extensively and with great success in other regions of North America.

"Frost seeding" means 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. Frost is generally not hard enough until 2:00-4:00 a.m. and is out of the ground by 8:00-10:00 a.m. Do not attempt this method of seeding when air temperatures drop below -8°C. The ground will be frozen hard enough to break the no-till equipment.

While this may be a narrow window and may not occur every year, the increase in yield from early planting using this technique can be as much as 25%.

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Aerial Seeding Winter Wheat

In short-season areas or in late wet seasons, consider aerial seeding. Aerial seeding is most successful when seed is flown on before 10% of the soybean leaves have dropped. The dropping soybean leaves will provide some cover and help retain moisture for wheat germination.

Results from aerial seeding have been disappointing. The seed is extremely vulnerable to slug damage. Slugs feed on the germ of the kernel, which can decimate 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 this problem.

The shallow root system that develops from aerial-seeded wheat is more prone to heaving injury and wind damage (see the section Depth of Seeding). In the spring, wheat plants are often attached to the soil by only one hair root. If this hair root breaks as plants twist with the wind, the plant dies. With these inherent risks, yields from aerial-seeded wheat are generally 10% lower than from drilled wheat, according to limited on-farm trial data. Therefore, aerial seeding is not a standard practice. When conditions dictate that aerial seeding is the best option, increase seeding rates to 4.9 million seeds/ha (2 million seeds/ac) to compensate for stand loss.

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Broadcast Seeding

Winter or spring cereal seed can be broadcast to speed up 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 the spreader.

Use airflow units to achieve the uniform spread pattern. Till fields at a shallow (7.5-cm or 3-in.) depth, twice at right angles and, finally, packed. This will help prevent streaking in the seeding pattern and improve seed-to-soil contact.

Depth of seeding is inconsistent with this method. Variable maturity and a 5%-10% reduction in yield often occur. If broadcast seeding, increase seeding rates by 10% to compensate for the potential variability.

Updates on Cereals: Tillage

No updates available at this time.

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Related links...

• Cereals

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