MAKING THE MOST FROM SOIL TESTING
First Published December 2015
With stocking rates at their peak in the district & excellent livestock prices, maximizing pasture productivity makes sound economic sense. To determine your soil’s fertilizer requirements, soil testing is an essential tool to make an informed decision. However, it is important to take a planned approach to soil testing to get the most out of the information, rather than randomly selecting paddocks. Some factors to consider before conducting soil testing this year:
1. Understand what you want to achieve: Soil tests are often the first point in property planning, used to assess land capability, help make landscape management decisions and as a diagnostic tool in the case of poor plant performance.
2. Prioritise paddocks: It is not usually practical to soil test each paddock annually. Choose several representative paddocks on the property to provide a guide to the fertility status on your farm
For example: 1 x introduced pasture, 1 x native pasture, 1 x lucerne paddock
and/or taking into account soil type difference: 1 x creek flats, 1 x light ridges).
3. Regularly test your soils: Accurately identify the location by GPS or landmark so they can be re-tested periodically at the same time of year. This will reduce the error associated with soil sampling & provide information on changing nutrient trends over time.
Remember: soil testing can be best described as a ‘blunt tool’ designed to provide a guide to the soil’s nutrient levels. It may take several years to see trends but this is when the value of soil testing is maximised.
4. Take samples correctly: Normal soil testing takes samples from 0–10cm depth. Deeper soil tests are from between 10–20cm. Ensure the samples are representative of the area, avoiding gullies, stock camps and all high nutrient load areas, e.g. ground around water troughs, gateways etc.
Call Landmark Daniel Walker today to get the best out of your soils with their consulting agronomist, Roger Garnsey.
MAXIMISING FORAGE CROP PERFORMANCE NEXT AUTUMN STARTS NOW
First Published January 2016
With harvest now finally completed, growers are already starting to plan for next year’s crop. Achieving a top result from a forage cereal crop requires sound planning, including effective weed control, adequate nutrition & optimum seedling establishment.
This year, Landmark Daniel Walker has grown Blackbutt oats in collaboration with a local grower to ensure supply of good seed. To maximise seedling establishment, Landmark has arranged for application of two important seed treatments, Awaken ST & Gaucho, which have proven to be highly effective in improving seedling nutrition & controlling insects/disease in forage oat crops, as described below.
AWAKEN ST (7-0-1) is a seed treatment containing zinc ammonium acetate with potash and a balanced micronutrient seed treatment package including boron, copper, iron, manganese, molybdenum, and zinc. There are several benefits from Awaken ST:
· Provides crucial micronutrients for early plant nutrition;
· Helps extract and release soil nutrients into the available soil solution;
· Promotes early plant vigor growth for improved yields
(as shown in the attached photo);
· Better root systems improve tolerance to drought and other stresses;
· Seed safe.
Gaucho & Barley Yellow Dwarf Virus:
Barley Yellow Dwarf Virus (BYDV) causes a disease in barley, wheat and oats which can lead to stunting of plants and subsequent losses in yield and quality. It is spread by aphids from infected plants to healthy plants when they feed. Once infected, a plant cannot be “cured” and significant damage can be caused by only a few aphids moving through a crop. The aphids rely on a green bridge over summer to thrive – they cannot survive on dead plant material. The risk is greater in early sown cereals, such as oats, as the aphids actively seek out the green material from these crops.
Barley yellow dwarf virus (BYDV) is spread to cereal crops from infected perennial grasses by cereal aphid vectors. When infected aphids move to healthy plants and start feeding they cause spreading patches of BYDV. In medium to high rainfall zones, where aphids are more likely to arrive early in the life of the crop, the damage to crops has the potential to be greater as more aphids are likely to be carrying virus. However, when these zones experience prolonged dry conditions before the growing season, aphids arrive quite late and the risk of damage from virus is low.
Cereal aphids (usually oat or corn aphids) pick up the virus whilst feeding from the vascular tissues of infected plants and carry it in their salivary glands for the rest of their lives. They can transmit the virus to healthy plants when they feed on these. They need to probe right into the vascular tissue of the phloem in order to do this, which requires deep and relatively long feeding. This type of transmission is called persistent because the virus persists in the aphid, usually until it dies.
BYDV infection affects the vascular tissues in the cereal plant, restricting movement of water and nutrients up the stem. Symptoms of BYDV include yellowing & reddening of the leaves & can be easily confused with nutrient deficiency (e.g. Nitrogen deficiency). Plants infected before the end of tillering are stunted and yields in sensitive wheat, barley and oat varieties can be decreased by up to 50%. In contrast, with late infection (post-tillering) of the crop, yield may be largely unaffected. In some cases the proportion of shrivelled grain increases, affecting quality. The effects on the plant may take several weeks to appear & can be magnified when plants are under stress such as in drought conditions.
BYDV spread can be controlled using established management techniques including the use of seed treatments (containing Gaucho) &, to a lesser extent, the use of insecticides (e.g. pyrtheroids) on crops (commonly two applications after sowing, at around 4 & 6 weeks) to control the aphid vectors.
For further information on sourcing high quality seed oats for sowing in early autumn, call Landmark Daniel Walker or their consulting agronomist, Roger Garnsey on 0429625880.
MAINTAINING A WEED FREE FALLOW OVER SUMMER
First Published January 2012
The recent rainfall has resulted in an increase in the summer weeds now starting to germinate in sprayfallow paddocks intended for crop/pasture establishment next year. It is important to ensure that these summer growing perennial (e.g. couch) and annual weeds (black stinkgrass, hairy panic) do not extract valuable soil moisture & nutrients over the summer period.
Early control of summer weeds in fallow paddocks is vital; as weeds increase in size & density, maturing plants tap into soil moisture from a greater depth. In addition, sowing may be impeded next autumn if summer weeds are not controlled.
Whilst soil moisture in the top 20-30 cm can be lost over summer due to evaporation, the removal of summer weeds allows any soil moisture below 30 cm depth to be stored for next year’s crop.
Research by the Grains Research & Development Corporation has clearly shown the economic benefits associated with summer weed control in fallows – for every 1$ spent on summer weed control, a return of $3 can be expected in terms of higher grain yield alone. Logically, in years of average rainfall, the benefits of maintaining a clean summer fallow is less than in dry springs.
Clearly glyphosate will form the basis of most herbicide mixes for summer weed control. However various mixing partners may be needed to improve the control of some hard-to-kill summer weeds. The following table provides information on the relative performance of a range of herbicides on several common summer weeds.
For further information on control of summer weeds in your fallow, contact Landmark Daniel Walker to arrange an inspection of your paddock with their consulting agronomist, Roger Garnsey.
BENEFITS OF AWAKEN ST ON FORAGE OATS THIS SEASON
First Published December 2016
Landmark Daniel Walker has secured good supplies of Blackbutt & Bimbil forage oats for early season sowing. To maximize oat crop performance, seed has been treated with Gaucho & Awaken ST.
Gaucho is applied to the seed for aphid control, which reduces the incidence of Barley Yellow Dwarf Virus (BYDV) in forage oats. BYDV is transmitted from plant to plant by aphids, usually the oat aphids, the corn aphid or the rose grain aphid. When aphids feed on plants their mouthpart, called the stylet, penetrates the leaf epidermis and enters the plant’s vascular system, namely the phloem. Within 15 minutes of feeding, the aphid either contracts the virus (if the plant is already infected) or it transmits the disease to the uninfected plant. It can only survive in living tissues and does not survive in stubbles or soils & it is not airborne. Symptoms of BYDV include sporadic patches of yellow, red or purple coloured leaves as well as crop stunting. BYDV reduces crop vigour & winter dry matter production & in severe cases, can result in crop death. It can also cause seed abortion, thereby reducing grain yield. Gaucho provides early effective control of aphids to reduce BYDV. Note: Do not graze for 9 weeks after sowing.
Awaken ST (7-0-1) is a seed treatment containing zinc ammonium acetate with potassium and a balanced micronutrient seed treatment package including boron, copper, iron, manganese, molybdenum, and zinc. The main benefits from this seed treatment include:
- Increased speed of emergence;
- Increased root mass and depth;
- Promotes plant growth;
- Improves overall plant health and vigour;
- Increases plant’s ability to deal with stressed conditions;
- The use of Awaken last year clearly showed improved early emergence & dry matter production in forage oat crops. Secure your forage oat seed supplies for autumn 2017 by placing your seed requirements now with Landmark Daniel Walker to avoid disappointment.
THE IMPORTANCE OF SULPHUR
First Published December 2016
Whilst there is much emphasis placed on addressing Phosphorus (P) levels in the soil for optimum pasture growth, Sulphur (S) is equally important.
Without Sulphur, plants fail to thrive and legumes cannot fix nitrogen from the atmosphere. Sulphur is a principal component of three essential amino acids needed to make plant proteins and deficiency limits growth.
Sulphur is also essential for symbiotic fixation of nitrogen by legumes, where Rhizobia bacteria in root nodules use atmospheric nitrogen to produce amino acids and proteins. Soil organisms process organic matter derived from legumes to release (mineralise) nitrogen to the soil for uptake by plants and other organisms.
Single Superphosphate is particularly effective where Sulphur (& Phosphorus levels) are critically low & a rapid response is required. The Sulphur (available in the sulphate form) in Single Super is available to the plant in days. In contrast, products containing elemental Sulphur are slow release & need to be converted into the sulphate form before it can be taken up by plants (taking several months). If your property has a strong history of Single Superphosphate with elevated levels of Phosphorus & Sulphur in the soil, then a slower release fertiliser product may be appropriate (e.g. BioAgPhos S10).
For further information on Sulphur, or choosing the most appropriate fertiliser for your situation, please call Landmark Daniel Walker or their consulting agronomist, Roger Garnsey on 0429625880.
PRODUCT UPDATE – GLYPHOSATE
First Published January 2015
Roundup Ultra Max; 570g/L GLYPHOSATE; more comprehensive weed killing capability, greater translocation qualities, 20 minute rainfast coverage & 1 hour spray to sow. Improved compatibility with over 50 tank mix partners. Reduced foaming and excellent viscosity properties.
Deadsure from Caltex; a new adjuvant or wetting agent to maximize glyphosate performance & reduce drift. For use in fallow spraying situations from a ground based boom spray rig when using glyphosate and/or phenoxy herbicide tank mixtures. Effective in improving rate of glyphosate-kill of grass and broadleaf weeds in fallow situations. Maintains glyphosate efficacy in hard water. Compatible with ammonium sulphate adjuvants. Effective when 2,4-D herbicides e.g. Amicide 625, are used in the same tank mix as glyphosate. Application rate: 250-500 mL/100 L.
Goal Tender 480SC Herbicide. A higher concentration of oxyfluorfen. Oxyfluorfen is a contact, LDPH (Light Dependent Peroxidising herbicide) chemical which is primarily taken up through foliar absorption rather than root uptake. It causes rapid disruption of the cell membrane after application which in turn causes cell leakage & death. Apply with a non-ionic surfactant when used as a spike with glyphosate. Twice as strong as the original Goal Herbicide
Lower odour. Lower chemical scheduling as exempt from
scheduling classification (has a modern, safer, water-based
carrier system which does not contain hydrocarbon
solvents). Lower volatility.
Awaken seed treatment on forage oats this year
Seed oats is likely to be in short supply again this season
but Landmark has secured supply of Blackbutt forage oats
in collaboration with a local grower, ensuring good supplies
of good quality, clean grain with no known contamination
issues, as the crop has been managed by our own
agronomist, Roger Garnsey, from sowing through to
harvest. In addition, this grain will be treated with Awaken
Seed Treatment, which is a Loveland product that has
shown significant benefits to early crop growth.
For further information on any of these products, call Landmark Daniel Walker’s consulting agronomist, Roger Garnsey, on 0429625880.
BLACKBERRY TRIAL RESULTS
First Published January 2014
A trial at Braidwood, NSW, was established in March 2013 to demonstrate the effectiveness of several different herbicide treatments against blackberry.
Table 1 lists the 5 treatments applied to mature blackberry bushes. These treatments ranged from non-selective glyphosate-based herbicide mixes to selective herbicides, such as Grazon Extra & Grass-up (generic equivalent to the Grazon DS, containing 300g/L TRICLOPYR & 100g/L PICLORAM).
Table 1: Treatments applied for control of blackberry in Braidwood 2013
|Treatment 1||500 mL Grazon Extra/100 L|
|Treatment 2||500 mL Grass-up Herbicide/100 L|
|Treatment 3||500 mL Grass-up Herbicide + 20 g Metsun 600 + 250 mL LI700/100 L|
|Treatment 4||400 mL Roundup CT + 10 g Metsun 600 + 250 mL LI700/100 L|
|Treatment 5||400 mL Roundup CT + 20 g Metsun 600 + 250 mL LI700/100 L|
The effects of the various herbicide treatments on the mature blackberry bushes are shown in the photo below. All treatments resulted in complete brown out of the blackberry bushes six months after application. There was no evidence of regrowth in any of the bushes, regardless of treatment. There was a faster brownout under the Grazon Extra treatment, however this did not result in an improved kill compared to the other treatments in this trial.
For further information on woody weed control this summer, please do not hesitate to contact our consulting agronomist, Roger Garnsey through Landmark Daniel Walker on 02 48 422405.
MAKING THE MOST OF YOUR FERTILIZER $ THIS YEAR
First Published January 2016
For most growers, harvest has finished this year & fertiliser topdressing of perennial pastures is in the forefront of peoples’ mind. Before organising your fertiliser delivery this year, the importance of soil testing cannot be understated. This will determine not only how much fertiliser you need, but also where it is needed most & how much is required. The cost of soil testing is minor compared to what most growers spend on topdressing fertiliser each year- so DON’T JUST GUESS, SOIL TEST!!!!
*It is also important to consider the grazing management of the property before spending money on fertiliser. Addressing low soil fertility can improve pasture production, but this additional feed needs to be effectively utilised to maximise profit. Dairy farmers are leading the way in this area through strategic strip grazing of paddocks once pastures have reached the critical 3-leaf stage of growth. Pastures are often ‘topped’ with mulchers after grazing to remove less palatable species before the next grazing event. Whilst this form of intensive management is considered beyond the scope of the average sized grazing farm at Braidwood, the grazing principles are equally relevant to the beef/sheep farmer as it is to the dairy farmer.
*A recent assessment by the University of Melbourne of Victorian dairy farmers highlighted that on many farms, only 50% or even less of the pasture is eaten; the rest is wasted. However, on some farms, 70% to 80% of the pasture grown is eaten; and not surprisingly, these are the farms that have the highest profit. In comparison, the average beef farmer in southern NSW utilises 30-40% of pasture grown. In a beef trading enterprise, pasture utilisation of 50–60% is possible in most environments, if limited stock are carried over the dry period.
*One of the most effective method of improving pasture utilisation on the property is to use larger mobs under a rotational grazing system & to subdivide paddocks into smaller paddocks (ideally according to land class). Both of these methods increase grazing pressure on pastures & reduce selective grazing of ‘ice cream’ species. Short, hard grazing events, followed by extended rest periods of 10-12 weeks (mainly during winter) are not detrimental to pastures & will actually favour desirable perennial grass/clover species but disadvantage lower quality, annual species.
So before you order the fertiliser truck just yet, consider some of the fundamental aspects that are key drivers of profit in a grazing system, including paddock subdivision & mob size. Addressing these key issues will assist in getting the most out of your fertiliser dollar invested on the farm. For any further information on grazing management, or soil testing this summer, please call Landmark Daniel Walker.
BARLEY YELLOW DWARF VIRUS (BYDV) IN OATS
First Published February 2015
BYDV causes a disease in barley, wheat and oats which can lead to stunting of plants and subsequent losses in yield and quality. It is spread by aphids from infected plants to healthy plants when they feed. Once infected, a plant cannot be “cured” and significant damage can be caused by only a few aphids moving through a crop. The aphids rely on a green bridge over summer to thrive – they cannot survive on dead plant material. Significant rainfall over much of the southern NSW in January 2015 has initiated a green bridge, which has the potential to host large populations of aphids which can transmit viruses between growing seasons.
Where does BYDV come from? BYDV is spread to cereal crops from infected perennial grasses by cereal aphid vectors.
How do aphids spread the virus? Cereal aphids pick up the virus whilst feeding from the vascular tissues of infected plants and carry it in their salivary glands for the rest of their lives. They can transmit the virus to healthy plants when they feed on these..
Symptoms of BYDV BYDV infection affects the vascular tissues in the cereal plant, restricting movement of water and nutrients up the stem. Symptoms include yellowing & reddening of the leaves and can be easily confused with nutrient deficiency. Plants infected before the end of tillering are stunted. Yields can be decreased by up to 50%.
Control BYDV spread can be controlled using established management techniques including the use of seed treatments (containing Gaucho) and to a lesser extent, the use of insecticides (e.g. pyrtheroids) on crops.
Use BYDV resistant cultivars where ever possible.
For further information on BYDV or aphids, call Landmark Daniel Walker’s consulting agronomist, Roger Garnsey, on 0429625880.
CHICORY: GRAZING MANAGEMENT
First Published February 2016
Chicory is a short lived perennial herb that can remain productive from 2-6 years. It is a valuable plant which provides high quality grazing over spring & summer. Here are a few pointers on grazing chicory for persistence & production:
- Don’t graze below 5cm (1500kg DM/ha)
- An optimum chicory stand contains 20-30 plants/m2. Around 30% of mature plants will die each year, due to fungal disease of the crown;
- The main objective is to maximise leaf production and minimise stem production.
- Employ rotational grazing in chicory stands for improved persistence & production: Chicory should ideally be rotationally grazed with a four block grazing system (between rest periods of 3–4 weeks, similar to lucerne).
- The easiest way to minimise stem development is through two quick, hard grazings to ground level, the first in mid spring (i.e., mid to late October) and the second in November.
- When introducing freshly weaned lambs in spring, Puna should be at maximum pre-graze height of 10-12 cm. Heights greater than this can result in slow acceptance, with fence line trekking and feed wastage likely;
- The major grazing management objective in spring is to ensure a high proportion of leaf relative to stem (i.e., 3: 1, or 70% leaf), rotation length and postgrazing residual height being the two critical factors.
For further information on grazing management of chicory, call Landmark Daniel Walker or their consulting agronomist, Roger Garnsey on 0429625880.
YOUR WINTER FORAGE CROPS
First Published February 2017
Many oat crops are well underway in the Braidwood area with excellent establishment & early growth due to the mild temperatures & high autumn rainfall that we’ve been enjoying this autumn. For many growers, these crops will be used to value add to weaner livestock as improved growth rates over the winter period. For others, they will be used as a feed supplement for cows after calving. However for the grass dominant crops (such as oats & ryegrass), there is the risk of lactating cows (usually older, high milking cows) suffering the effects of milk fever (low calcium), grass tetany (low Magnesium levels) or a combination of both, particularly under cold, overcast winter weather. On farms it is mostly seen in cows prior to and soon after calving. In sheep it is usually seen in ewes in late pregnancy but can be seen in all classes of animals. The disease is seen when the body fails to mobilise enough calcium from the bones to maintain normal blood calcium levels, or when certain compounds known as oxalates bind up the calcium.
Whilst the issue of milk fever or grass tetany is not seen every year, it is important to minimise the risk of these disorders. As such, I would suggest adopting the following precautionary measures when introducing lactating livestock onto forage oats/ryegrass dominant crops this winter:
- Avoid introducing pregnant cattle onto crops prior to calving;
- Don’t introduce hungry cattle onto crops – fill them up on pasture/hay before putting them on the crop;
- Ager is important: older, higher milking cows are usually more affected than younger heifers;
- Avoid introducing cattle onto the crop on overcast, dull winter conditions;
- Provide a feed supplement of equal proportions of salt/lime/Causemag as well as legume-based hay when grazing cereals/ryegrass. Livestock should be fed this in the weeks before introducing them to winter forage crops to ensure intake of these supplements once grazing of the crop begins.
In this way, liveweight gains from these crops will be maximized & losses minimized. For further details on getting the most out of grazing winter cereals & ryegrass this winter, contact Landmark Daniel Walker or their consulting agronomist, Roger Garnsey on 0429625880.
MAXIMISING WINTER FEED PRODUCTION BEFORE IT’S TOO LATE!
First Published February 2012
With the onset of cooler autumn conditions approaching, it is timely to think about the winter feed demands of your livestock & how that might be best met. There are several options, including supplementation with hay, silage and/or grain, however one of the most cost effective methods is to grow more grass with the strategic use of additional fertilizer/growth promotants.
Urea (containing 46% Nitrogen) can be used at strategic times during the year in a very cost-effective manner to produce additional winter feed. Whilst pasture legumes fix ‘free’ Nitrogen (N) during the warmer months of the year, once soil temperatures fall below 10 oC, clover growth ceases, as does N fixation – as a result, our soils typically experience a deficit of available N during April-August. An application of N prior to the onset of these conditions can improve herbage mass leading into a period of expected N deficiency. In addition, urea can be used to supply additional N to maximize spring hay production.
When choosing a paddock for urea, select areas with the following attributes:
1. High levels of improved pasture species, such as ryegrass (in particular), phalaris & cocksfoot;
2. Good history of Superphosphate use – there is no point in applying N to boost pasture growth if Sulphur or Phosphorus is lacking;
3. Good soil moisture levels, but avoid areas prone to waterlogging;
4. Low weed burden;
5. Avoid light textured soils prone to leaching.
Urea may be applied to pastures anytime from May-September, depending on when the additional feed is required. Feed responses to N typically occur 4-6 weeks after topdressing. Do not graze within 2-3 weeks of application due to the potential for nitrate poisoning of livestock at this stage.
The most effective rates of urea are typically 85 kg/ha (or 35 kg N/ha) to increase winter pasture production. Apply to pastures with re-growth of around 1500 kg Dry Matter (DM)/ha (4-5 cm height). Do not allow pastures to become rank¸ as these pastures will become inefficient at using the applied N. Avoid application of N fertilizer for more than 2 years, as pastures tend to become grass dominant.
Typical increases of 400-500 kg DM/ha from strategic N applications have been been found in pastures. This equates to a cost of around 9c/kg DM produced (compared to the cost of hay/silage at 30 c/kg produced) making the use of urea on pastures a very economical method of increasing the supply of winter feed for your livestock.
In addition to urea, ProGibb SG offers an alternative option for increasing winter feed. Essentially a naturally occurring hormone (40 % gibberellic acid), ProGibb was originally sold into the horticultural market to promote desirable harvest effects (e.g. fruit thinning, elongation and ripening in grapes and citrus). However, it was also found to promote cell elongation, division and hence, DM production in pasture grasses in winter, due to low production of gibberellic acid during the colder winter months. In summary:
- Application rates vary from 10 g ProGibb/ha + 10 mL Active 1000/100 L for phalaris–based pastures up to 20 g/ha + wetter for ryegrass and cocksfoot pastures which are less responsive.
2. Apply 100 L/ha of spraymix by boomspray;
3. A pasture base of at least 1000 kg DM/ha is recommended before application;
4. Apply only to pastures which are at least 12 months old;
5. as with urea, grass species are more responsive to ProGibb than broadleaf or clover species;
6. typical response of an additional 500-700 kg DM/ha (similar to urea) have been recorded with no loss in feed quality;
7. response can be seen within 7 days, lasting about 21 days (subject to adequate soil moisture and nutrients). In comparison, responses to urea will take 2-3 weeks, with the peak in response occurring 6-8 weeks after application;
8. ProGibb can also be used in combination with urea for a greater growth response. The two products applied together have a synergistic effect;
9. After application, rest the paddock for up to 21 days. You can then follow up with a further application every 3-4 weeks after the initial application to maximise winter growth of selected paddocks on the farm;
10. Best results when ambient temps are 6-15 oC (e.g. June-August). Application during heavy frosty periods should be avoided;
11. Very cost competitive @ approx. $1/g or up to $20/ha + application costs, compared to urea @$70/ha + spreading;
12. It is an organically certified product with a nil grazing withholding period.
13. can be tank mixed with insecticides & selected herbicides.
For further information on strategic fertilizer and ProGibb use for increased winter pasture growth, call Landmark Daniel Walker today to arrange an on site appraisal of your situation with their consulting agronomist Roger Garnsey.
FILLING THE WINTER FEED GAP IN THE BRAIDWOOD AREA
First Published February 2013
With the excellent recent late summer rainfall & high stocking rates, Braidwood producers will be looking to provide additional feed this winter to carry their livestock through the colder months. There are a number of options to increase winter feed on hand, as outlined below.
1. Establishing winter active crops early in the season
There are a wide range of winter active crops that can be grown in the Braidwood area to provide additional feed at critical times of the year, including forage brassicas, Italian ryegrass & grazing cereals. Each crop has its own advantages; cereals & forage brassicas sown in early autumn provide a greater amount of early feed than ryegrass, but do not provide late quality spring/summer feed that ryegrass can. In addition, early sown forage brassica crops tend to bolt to head mid spring rather than staying vegetative into summer. These differences in Dry Matter (DM) production from early sowing are reflected in the production figures collected from a trial at Yass in 2007 (refer Figure 1 overleaf).
Apart from the differences in DM production, it is also important to remember some of the other factors when choosing a winter active forage crop, as summarised in the following table:
Table 2: Comparison of various winter growing forage crops.
|Grazing Cereal||Italian ryegrass||Forage brassica|
|1. Annual crop
2. More competitive against early weed competition
3. Some post-emergent weed control options in cereals – less in oats than triticale or wheat
4. Many varieties are acid toleant
5. 1st grazing: Typically
8-10 weeks after sowing
6. Provides high quality, early winter feed compared to a ryegrass
7. Can be cut for hay or silage in spring
8. Cost of establishment: $80/ha + fertiliser
|1. Can last from 1-4 years, depending on variety
2. Must be sown into a well prepared paddock (sprayfallowed previous spring) to achieve optimum results
3. No herbicide options for selective grass control, but broadleaf weeds can be controlled
4. Acid sensitive: avoid highly acidic soils or apply lime before sowing
5. 1st grazing: Typically 10-12 weeks after sowing
6. Provides higher quality, late season feed compared to a cereal
7. Can be cut for hay or silage in spring
8. Can be sown with additional clovers, chicory or lucerne to provide a year round High Performance Pasture
9. Cost of establishment: $40/ha (annuals) – $120/ha (2-4 year ryegrasses) + fertiliser (no lime)
|1. Annual crop
2. Provides a disease break
3. Must be sown into a well prepared paddock (eg sprayfallowed previous spring) to achieve optimum results
4. Annual grasses can be effectively controlled in this broadleaf crop
5. Acid sensitive: avoid highly acidic soils or apply lime prior to sowing.
6. Provides greater winter DM than a cereal when sown early
7. 1st grazing: 6-12 weeks after sowing
8. Not for hay or silage in spring – this crop is suitable for grazing only
9. Cost of establishment: $40/ha + fertiliser (no lime)
- Topdressing with fertilizer at strategic times of the year to perennial pastures & crops
Nitrogen (N) fertiliser can be used at certain times of the year with very effective results to increase DM production in pastures. Pasture legumes fix atmospheric N which drives pasture production (of grasses in particular). However, during the colder winter months when soil temperatures drop below 10 oC, clovers stop growing & fixing N. At these times, 85-100 kg Urea/ha can be topdressed onto pastures to increase pasture growth. Timing is critical, typically occurring in late April/early May when soil temperatures are starting to drop. Livestock will not be able to graze these fertilised paddocks for 4-6 weeks after application to avoid the risk of nitrate toxicity. Peak responses to additional N fertiliser applied to pastures can be expected 6-8 weeks after application.
Paddock choice is important to get the greatest bang for your buck. Choose a paddock which has the following characteristics:
· High levels of improved pasture species (particularly grasses such as ryegrass, cocksfoot & phalaris, but not winter dormant fescue);
· Good fertiliser history – there is no point applying additional Nitrogen to boost pasture growth if Phosphorus and/or Sulphur is limiting growth;
· Good soil moisture levels, but avoid areas prone to waterlogging;
· Low weed burden.
Typical increases of 400-500 kg DM/ha can be expected from Urea applications in early autumn as described above. This equates to around 14c/kg DM produced which is very cheap feed compared to the cost of supplementary hay at 30 c/kg DM.
3. Applying gibberellic acid to stimulate pasture growth
Gibberellic acid is a naturally occurring hormone which was originally sold into the horticultural market to promote desirable harvest effects (e.g. fruit thinning, elongation and ripening in grapes and citrus). However, it was also found to promote cell elongation, division and hence, DM production in pasture grasses in winter, due to low production of gibberellic acid during the colder winter months. It comes under various tradenames, including Gala & Progibb SG. As a result, these gibberellic acid products offer an alternative to Urea for producing additional winter feed in perennial pastures and grazing cereal forage crops. Application rates are typically 10-20 g/ha + 10 mL Active 1000/100 L. Phalaris–based pastures are most responsive to gibberellic acid, followed by cereal crops, ryegrass and cocksfoot. At around $1/g + application costs, gibberellic acid is very cost competitive to increase winter feed supply. It can also be conveniently applied in combination with most broadleaf weed herbicides & insecticides to provide effective pest control in the one pass.
For further information, please do not hesitate to contact our consulting agronomist, Roger Garnsey through Landmark Daniel Walker on 02 48 422405.