Oil radish is a cross between fodder radish, fodder rape and rapeseed. It was developed as a plowdown and this is its primary purpose. It is also refered to as oilseed radish. Although relatively unknown to most farmers, it is gaining in popularity on organic farms as a green manure or winter cover crop.

1. Reasons for

crop selection

* Market

Oil radish currently sells for $0.75/lb, and yields have been reported as high as 1100 lb/acre, making a gross income of $825/acre to the seed grower.

* Root structure

Oil radish possesses a central radish-like tap root with an enormous amount of roots sprouting from it. Its ability to absorb soil nutrients,especially nitrogen, and tie them up for the winter makes this an ideal cover crop.

* Residue addition

Oil radish has a heavy plant growth. It is possibly to get ten tons of green matter per acre after 45 days. It can be seeded after a cereal is harvested and still provide significant benefits to the soil by winter. Oil radish makes a good alternative if there has been a missed planting or poor establishment.

* Soil conditioning

Oil radish is a renowned soil conditioner. Its large tap root with a proliferous hair root system extends well into the subsoil, loosening and aerating. Many farmers have observed that soils usually requiring fall plowing have excellent tilth in spring when an oil radish stand is left untouched over winter. It is a sulphurous crop, and warms the soil.

* Nutrient benefit

Oil radish is not a large nitrogen source, but it does encourage the growth of the bacteria that will be needed in following years by nitrogen fixing plants.

Oil radish is an opportunist in the area of nutrient consumption. It responds dramatically to manure application, immobilizing in its biomass large amounts of nitrogen and phosphorus for the next yearÕs crop. A primary function of oil radish is to ensure that your nutrients are not exposed to leaching. Without the use of oil radish many valuable nutrients would be lost.

Oil radish is a heavy nitrogen user, responding well to residual nitrogen. Growth will be slowed in soils low in nitrogen. It would appear to be an ideal crop to carry over the nutrients from manure application.

* Weed control

Oil radish can mature in less than 60 days. It grows to a height of three feet in six to eight weeks. Flowering weeds will not be so prevalent the year after oil radish, and it may control nut-sedge.

* Silage

Oil radish is not recommended as a silage crop in its flowering stage, as its pungency may be adverse to ruminant system. Using it in its pre-flowering stage may be acceptable.

* Pollinator

Oil radish is a heavy bee pollinator in the warm months.

* Residue addition

Oil radish residue is brittle and works in easily in the spring.

* Erosion control

Erosion control is excellent

2. Crop requirements

* Soil

Oil radish grows on all soil types.

* Temperature

Heat units not important when growing oil radish. In south-west Ontario which has an average of 2700 corn heat units, early seeding is recommended.

3. Planting Methods

* Timing

Planting should occur in the last two weeks of August to capture the maximum amount of nutrients while avoiding the problem of volunteer oil radish the next growing season. Oil radish is capable of withstanding heavy frost. However, the crop is winter killed.

Growers must adjust seeding dates so that the crop does not have time to set seed before winter. In the 2700 heat unit area a seeding date of August 15 will usually mean no seed set. If, however, the crop approaches seed set before heavy frosts, growers can plow down, disc, or chop it down in the fall.

* Seedbed preparation

Seedbed preparation for oil radish is similar to the preparation made for cereal grains. If oil radish follows a cereal crop harvest, (or early maturing specialty crops like vegetables), in the crop rotation, the ground should be worked well. Chisel plow, cultivate, and harrow, and make sure that the seed bed is firmed (rolled) after planting.

Volunteer oats or barley compete heavily with oil radish and therefore repeated cultivation should be used to eliminate most viable seed before planting the oil radish. Volunteer winter grains (wheat, spelt, rye) tend to be less aggressive. Sprouted at this time of year they grow out instead of up, and no cultivation is required.

* Seeding rate

Oil radish seed is inexpensive ($12-15/acre) and is easy to reproduce seed on the farm. A seeding rate of 15 to 20 lbs/acre if broadcast and 10-12 lbs/acre if drilled in a well-prepared seedbed is recommended.

The oil radish seed is small, similar in size to canola seed and therefore must not be planted too deep. Regardless of seeding method, firming the soil after seeding is a good practice with summer seeding, especially if the soil is somewhat dry. Rolling is sometimes practiced.

Seed of oilseed radish seed has up until now not been handled by traditional seed companies in Ontario. Most of the seed available has been grown by farmers who use the crop themselves for ploughdown and have surplus seed for sale. Seed has sold in the $.60 - $1.00/lb range. Your local Ministry of AgricultureÕs soils and crop specialist may know of seed sources in your area.

If one plants oilseed radish in the spring to produce seed, seed shatter before harvest is not a problem, but there certainly will be some seed loss during combining. Be prepared to control volunteer plants in future years.

4. Post-planting

management

* Harrowing

Volunteer wheat is not too much of a problem as a competitor for oil radish. However, volunteer oats or barley are much more competitive and can reduce the oilseed radish stand by up to 50 percent. Some growers will work a spring grain field once after harvest to induce grain sprouting, and then rework the soil, and seed the oil radish about two weeks later.

* Weed control

Oil radish can produce viable seed from a summer seeding. It can become a weed problem in future years if planted early, or if the fall growing conditions were very good. This seed can remain viable in the soil for several years. To prevent this problem, oil radish should be disced under before it sets seed.

5. Diseases

Oil radish is quite susceptible to white mold attacks during the its flowering period in July, particularly in wetter years. Thus it should not be grown for seed if other crops like white beans, canola and sunflowers which are also susceptible to white mold, are also being grown on the farm. (There are no reports of white mold problems when oil radish is grown as a fall cover crop. This is probably because of the low temperatures if the crop flowers in October).

6. Incorporation as

green manure

In good conditions oil radish can grow very rapidly. It is possible to have two to three feet of top growth and a profusion of blossoms in four to five weeks. Six to eight weeks after seeding there would normally be about three feet of top growth. This provides excellent soil protection over winter. Once winterkilled, the plant residue becomes easy to handle by spring. Oil radish should not be plowed under; disking is preferable.

Oil radish that is planted after September 1st is usually not worthwhile as a nutrient conserver, but will still be adequate as a ground cover. The disadvantage to this minimal growth (less than one foot) is the absence of any significant soil aeration effect from the roots.

7. Suitable following crop

It is not a good idea to follow oil radish with another brassica, but with that exception, most crops can follow oil radish.

seedbed is recommended.Othe publishing of this handbook

Crop ble seed from a summer seeding.

* Disease control erefore5. Oil radisha ,isin the,6s (canola, mustard, cabbage)ugh3.10 Oil Radish

OOil radish hould as its volunteers will create problems the following year, but it should be sown as soon as possible after harvest the maximum amount of nutrients providing relatively little competition toollowing-year volunteers a problem.he spring to produce seed, seed-provides a good source of pollen and nectar for beesnt of roots sprouting from it. Oil radish has proven itself to be an ideal cropa wide variety

A primary function of oil radish is to ensure that valuable nutrients are not lost through exposure to leaching. It immobilizes in its biomass large amounts of nitrogen and phosphorus to be used by next years crop. It also provides excellent erosion control over winter.

vy plant growth. It is possible (although rare) Under good conditions there will be 2-3 feet of top growth and a profusion of blossoms in four to five weeks. therefore The residue is brittle and is easily worked into the soil in spring. I planting or poor establishment, oil radish makes a good alternative crop.

The rapid growth - to one metre in six to eight weeks - makes it very competitive against most weeds. Farmers have reported finding it useful where nutsedge was a problem.

( it encourages the growth of bacteria that will be needed by nitrogen fixing plants!? should something about sulphur go in here?

and acidifying effect around roots which helps make minerals available )

Diversity can be increased in a rotation of predominantly small grains and legumes by including oil radish which is a broad leaved cruciferous plant.

As more farmers become interested in the crop there will likely be an increased demand for seed. Oil radish has not been handled by traditional seed companies in Ontario. Most of the seed available has been grown by farmers who also use the crop for plowdown. Yields have been reported as high as 1100lb/ac, which provides a good return to the seed grower.also provides a good source of pollen and nectar for bees¥ Crop requirements is a heavy nitrogen user, and it responds dramatically to liquid manure( 22000L/ha or 2000gal/ac) or compost applications directly onto the gowing plant. Growth is slower in soils low in nitrogenIt will grow well in a wide variety of soil types.Heat units are not a vital factor when growing oil radish. It is capable of withstanding heavy frost. The crop, however is winterkilled.

¥ OIl radish for seed can be planted at any time from spring until ??

For a cover crop plas soon as possible after harvest he maximum amount of nutrients. If the crop does approach seed set before heavy frosts, disc or chop it to prevent volunteer oil radish creating problems the following year.