- Brassicas
- Ryegrasses
- Cereals
- Other
- Approximate dry matter production by the date of sowing
- Winter Greenfeed Options
Greenfeed Options
Sowing greenfeed is a high priority after the drought, whether it be into land that has been cropped, into run-out paddocks or into land that has been cultivated.
As a rule of thumb, the later sown crops give less feed of lower quality and are available later in the winter. As yields can vary so much depending on sowing date, location and time of grazing, the yield data given here must be used as a guide only.
Brassicas
Brassicas are high yielding, highly digestible forage.
The choice of cultivar will depend on the class of stock to be fed, the timing of the feed and if there is to be single or multiple grazings.
Brassicas must be sown into a firm fine seedbed. Do not plant more often than one year in five, as clubroot may become a problem. Do not sow with a soluble fertiliser (Cropmaster 15 or 20) unless the seed is pelleted. DAP is best for sowing. Brassicas require both N and P, but not S if the index is above 8. An insecticide is required especially after a drought.
Turnips may be sown until the end of February at 0.75 kg/ha, with or without the addition of a light dressing of 5 kg/ha annual ryegrass. York Globe or Appin Stubble Turnips are two commonly grown turnips.
Bonar forage rape (90-100 days) or Pasja Forage brassica (50-70 days) can be sown until mid February as they are early maturing. This is a turnip hybrid bred for rapid growth, multiple grazings and high stock performance. Emerald rape (80-100 days) may be sown until the end of February if under good conditions. All may be sown with ryegrass. Care is needed if brassicas make up a large proportion of the diet. Brassicas are highly digestible and feed flows through the animal very rapidly. Brassicas should be fed in combination with pasture or hay, sources of fibre that slow down the rate of feed passage through the animal, allowing more efficient uptake of nutrients from gut contents. Brassicas are associated with anti-nutritional factors, including SMCO, glucosinolates and nitrates. Animal productivity may be reduced if brassicas comprise a large proportion of their diet. Avoid the use of S fertiliser at sowing to reduce SMCO problems. Nitrate can become a problem with brassicas, ryegrasses and greenfeed cereals if crop growth is rapid after a period of slow growth (eg drought) and under overcast, dull conditions. If in doubt, get samples of the crop tested for nitrate content before grazing. Nitrate concentrations should preferably be less than 1% of dry matter. Crops with concentrations of 2% or more nitrate should not be grazed.
Ryegrasses
Annual and hybrid ryegrasses are high yielding nutritious and will give better spring production than either brassicas or cereals. They may be either diploid (Italian, Concord, Cordura, Mavrick Gold, etc) or tetraploid (Tama, Moata etc).
Ryegrasses can be sown into a rougher seedbed than brassicas, but late sowings will reduce winter yields. Sowing with DAP or Cropmaster 20 at 125 kg/ha will give additional feed, and Urea may be applied after establishment if soil temperatures are 7-10°C. Ryegrasses should be sown before the end of February.
Ryegrass may be affected with grass grub and Argentine Stem Weevil. ASW is not usually a problem if ryegrass is sown after the start of February. Earlier sowings should be treated with insecticide (Thimet or Gaucho) or use Superstrike treated seed.
Sowing rates should be 15-25 kg/ha depending on seed size. Sow into a firm seedbed or direct drill.
Italian ryegrasses provide high yields of highly digestible winter feed. Like brassicas, nitrate problems can occur for animals grazing Italian ryegrasses over the winter period.
Cereals
Oats, ryecorn and triticale are all commonly sown as cereal greenfeeds but wheat and barley can be used. The cereal greenfeeds are useful as they can be late sown into a rough seedbed, and give a high yield but quality is lower, and in the case of oats may be liable to frost damage if it gets too mature. Thus, they require feeding earlier if early sown.
Sow at 90-100 kg/ha with 125 kg/ha Cropmaster 20 or DAP. The seedbed may be moderately coarse and sowing depth should be 35-50 mm.
May be sown until the end of April, but late sowings will give little winter feed except in favoured positions.
Digestibility characteristics and energy levels for greenfeed cereals are not as good as for brassicas or Italian ryegrasses. Nitrate toxicity can be a problem for greenfeed cereal crops.
Other
Lupins, either brown or white, have been used for greenfeed but often seed is difficult to obtain. The seed is moderately large, so seedbeds can be coarse. The seed is usually sown at 60 kg/ha in association with oats or ryecorn. Lupins have the advantage of fixing nitrogen if allowed to survive through the spring.
Feed peas have been trialed for winter feed and may have a place on some farms. The seed cost will be moderately high and peas do not grow well under cold or wet conditions. Peas should not be grown if freezer peas, etc are in the rotation.
Approximate dry matter production by the date of sowing
| Sowing date | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Total Dry Matter | |
|---|---|---|---|---|---|---|---|---|---|---|
| Turnips | 1-Feb | 600 | 600 | 800 | 600 | 300 | 2900 | |||
| 1-Mar | 500 | 600 | 600 | 400 | 2100 | |||||
| Annual | 1-Feb | 50 | 200 | 450 | 450 | 300 | 200 | 400 | 1000 | 3050 |
| ryegrass | 1-Mar | 100 | 300 | 450 | 300 | 200 | 400 | 1000 | 2750 | |
| 1-Apr | 100 | 300 | 200 | 200 | 400 | 1000 | 2200 | |||
| Perennial | 1-Feb | 50 | 150 | 450 | 300 | 200 | 200 | 400 | 800 | 2550 |
| ryegrass | 1-Mar | 50 | 200 | 300 | 200 | 200 | 400 | 800 | 2150 | |
| Greenfeed | 1-Mar | 100 | 300 | 450 | 300 | 200 | 1350 | |||
| cereals | 1-Apr | 100 | 300 | 300 | 200 | 500 | 1500 | 2900 | ||
| 1-May | ||||||||||
| Pasture | 360 | 450 | 300 | 180 | 150 | 300 | 900 | 2640 | ||
| kg/ha/day | 12 | 15 | 10 | 6 | 5 | 10 | 30 |
Winter Greenfeed Options
| Option | Latest Sowing Date | Potential 100 Day Winter Yield | Positives | Negatives |
|---|---|---|---|---|
| Brassica, Pasja or Appin | Mid to late March | 4.5 tonnes DM/ha | High quantity of feed; Highly digestible, very high energy, high CP feed; Pasja rapid growth, earlier source of feed; Appin, more winter-hardy. | Anti-nutritional factors-nitrates, SMCO, glucosinolates; Highly digestible, may need extra source of fibre to slow feed passage through gut. |
| Italian ryegrass/brassica | Mid to late March | 3.5 tonnes DM/ha | High quantity of feed; Highly digestible, high energy, high CP feed; Nutritionally superior to 100% brassicas. | Highly digestible, may need extra source of fibre; Nitrates. |
| Italian ryegrass | Mid to late March | 3.0 tonnes DM/ha | Moderate quantity of feed; Multiple grazings; Highly digestible, moderate energy, high CP feed; Better spring production than brassicas. | Less feed over winter compared with brassicas; Nitrates. |
| Hybrid ryegrass | Mid-March | 2.5 tonnes DM/ha | Persists through into summer; Can have similar DM production to Italians (hybrid dependent). | Lower quantity of feed through winter; Nitrates. |
| Cereals (oats, triticale, winter wheat, ryecorn) | To late April | 3.0 tonnes DM/ha | Frost tolerant; Potential to hold over for grain; Can still get moderate yields from later sowing. | Poorer quality than ryegrass, brassicas; Fewer grazings during winter; Nitrates. |
Ken Muscroft-Taylor
Agricultural Consultant
Agriculture New Zealand
Darfield
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North Island Regions
Sector Performance Policy
MAF Policy
Hamilton
NEW ZEALAND
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