Management Notes are prepared by staff from the College of Agriculture, Food and Rural Enterprise (CAFRE). Questions and comments are welcome to allow CAFRE to address the issues that are important to you. Please contact the author directly. CAFRE is a college within the Department of Agriculture and Rural Development (DARD).
Turn cows out to grass as soon as possible
DAIRYING
Prepared by: Michael Garvey
e-mail: michael.garvey@dardni.gov.uk
telephone: 028 3752 9054
Turnout
Turn cows out to grass as soon as possible
As grass is the cheapest feed turn cows out as soon as ground and weather conditions allow. Walk your farm and see how much grass you have. You will have more than you think!
Don’t be afraid to graze cows on a grass cover of 2500 kg dry matter per hectare (the ankle of your boot). Graze grass down to 1500 kg dry matter per hectare (the heel of your boot). Start grazing for three hours and build this up to half days over a period of a week to ten days.
Aim for an initial grazing rotation of between 25 and 30 days to allow completion of your first grazing cycle before grass covers get too heavy. A surge in growth could mean by the time you reach the end of the first grazing cycle covers are too heavy for cows to graze out cleanly, making it more difficult to maintain grass quality throughout the grazing season.
Future Herd at Greenmount.
At Greenmount Campus the aim is turnout some of the Future Herd cows to the driest fields when ground conditions allow. The grazing group will consist of cows back in- calf producing less than 30 litres and more than 100 days in milk. Fields will be set up with different entry and exit points. Cows will go out with an edge to their appetite and graze for two to three hours, targeting 5 kg grass dry matter intake. A grazing group of 60 cows requires 300 kg of grass dry matter.It will therefore take three days for this group to graze a one hectare paddock with a pre-grazing cover of 2500 kg dry matter to the target residual cover of 1500 kg dry matter per hectare. To achieve this, the group will be offered one third of a hectare daily and a back fencer will be used to subdivide the paddock to improve grass utilization.
The Future Herd is a high yielding herd that is successfully grazed. Last year 40 cows were grazing on the 10th March. From mid-March to mid-April cows were drafted at morning milking and lower yielding cows went straight out to graze. The size of the grazing group increased gradually and by mid-April the entire herd was grazing for half a day. By the end of April a group of cows were grazing full-time.
Milk from forage
Improving milk from forage is critical at current milk price. In most cases, March grass has a higher energy value than the silage cows were fed. Full March grazing has the potential to produce 20 litres of milk. Getting your cows out to grass in March and good management will allow you to increase your milk from forage. Practically this requires you to increase the M+ in the parlour computer feed settings by 3 to 4 kg of milk at turnout. The few hours grazing after morning milking will save about 1.5 kg of concentrate per cow daily, replacing over half a tonne of concentrate a week for 50 cows. Continue to adjust the M+ in the parlour computer feed settings as cows move to full- time grazing. In addition to the immediate savings in concentrate costs there should be improvements in milk protein and yield.
The message is clear. Get some cows out grazing as soon as conditions allow. Adjust the M+ in the parlour computer feed settings at turnout as cows move to full-time grazing. Have your grazing rotation fully established by the third week in April.
BEEF AND SHEEP
Prepared by: Darryl Boyd
e-mail: darryl.boyd@dardni.gov.uk
telephone: 028 9034 0957
Importance of lime
By this stage many of you will have, or be thinking about, getting soils analysed before the application of slurry or manures. This is good practice as fertiliser bills can be reduced by applying only what is needed, according to phosphorus and potassium indices from the analysis. It also answers the question that is often asked “What fertiliser should I use?”
The pH result is often overlooked, but by correcting this perhaps the greatest savings can be made. pH is the measure of acidity or alkalinity and is a major factor contributing to nutrient availability. For example, potash availability for plants at pH 5 is 52% compared to 100% at pH 6.The natural pH of a soil depends on the nature of the material from which it developed and can range from 4 to above 8.Over time the pH of the soil can fall and become acidic for many reasons including heavy rainfall, crop growth, leaching and using large amounts of some nitrogen fertilisers. It is therefore important to analyse soils once every four years.
The recommended pH for optimum grass growth on permanent grassland is 6 to 6.5. Soil analysis provides a liming recommendation to bring the pH up to this level. On peaty soils the optimum pH is lower at 5.3.
What liming material should I use?
Another query that arises regularly is the liming material to use. The liming recommendation provided by the analysis is in tonnes per hectare and is based on using ground limestone. Liming materials are assessed by comparing their neutralising value (NV) or ability to neutralise acid compared to pure calcium oxide which is considered 100%. The table below outlines approximate NV values for typical materials:
Material
Neutralising values
Calcium oxide
100
Ground limestone
50
Ground magnesium limestone
50-55
Hydrated lime (slaked lime)
70
Quick lime
80-95
NV figures for the same type of lime may vary so ask the manufacturer
If using materials with a NV that differs from 50 (ground limestone) remember to adjust the application rate. It is also important to compare costs on a cost per unit of NV rather than cost per tonne. Also take account of other nutrients in the liming material. For example, magnesium limestone can be used to improve both pH and correct a soil magnesium deficiency, however when this is applied to soils already high in magnesium it could induce a potash deficiency in the crop.
It is important to follow the application rates (adjusted if required) and a single application of more than 5 tonne per hectare should not be applied. Avoidover-liming as this may induce deficiencies of trace elements such as selenium, cobalt and copper which could have an adverse effect on livestock performance.
Granular lime
Granular limes are formed from very finely ground particles of calcium or magnesium carbonate. The powders are formed into granules for ease of storage, transportation and more accurate application purposes. They are also advantageous for quick reactivity and spot treatments. As they are manufactured from natural carbonates granules have a similar NV to other natural liming products. The manufacturing process adds cost and consequently their use is generally less than their bulk counterparts. Also they don’t provide a long term pH correction through the whole soil/rooting zone and are not suitable for long term liming rotations.
SHEEP
Lambing records
Accurate records at lambing, whether paper based or electronic, are vital for making informed decisions about replacements/culling at a later stage. What should you record?
Lambing – unassisted, minor intervention or manual delivery
Reasons for lambing difficulty – management, over-sized lambs or malpresentation
Mothering ability
Lamb numbers per ewe
Lamb viability
Other ewe problems – teat/colostrum problems, prolapse etc.
Before decisions are made it is important to determine if the problem is specific to the ewe or if it was due to pre-lambing management. Using lambing and performance records are key to improving flock performance from one year to another.
HORTICULTURE
Prepared by: Kieran Lavelle
e-mail : kieran.lavelle@dardni.gov.uk
telephone: 028 3752 9060
Top fruit scab control
Frequent winter storms and persistent rainfall since late autumn left many orchards slow to drain and wet underfoot. It may take another week or two before alleyways are dry enough and the ground sufficiently solid to support a tractor and pulveriser, allowing you to deal with accumulated prunings.
Apple and leaf scab
The stormy weather did provide one unusual benefit in more exposed orchard sites. Last autumn’s fallen Bramley leaves were blown away from below the trees by the winds and are no longer a direct source of apple scab spores as temperatures rise and buds break this month. Overwintering spore bodies in leaf litter have always been a serious issue in local orchards. In fact, growers who have recently tried to remove or mulch fallen leaves (as much as is practical) seem to find less scab disease pressure at the start of the growing season. This can be a slow, laborious task but has the great advantage of reducing total fungicide usage.
In 2014 and 2015, spring was marked by at least three weeks of high pressure and exceptionally warm temperatures at some point during March and April. This resulted in exceptionally rapid blossom expansion and leaf emergence. If this happens this year, it is wise to schedule shorter intervals between scab spray applications to ensure good foliar coverage for the time when the weather breaks to rain and scab conditions, as it inevitably will! Highly active systemic products or quality protectants are always worth including in your programme when scab threat is significant.
If you do not receive mobile telephone text alerts (issued when apple scab infection periods are detected at AFBI, Loughgall), please text your details to Graeme Cross, CAFRE Top Fruit Development Adviser on 07717 732 659.
Protected crop planting and preparation techniques
Carry out soil sampling for greenhouse soils annually and outdoor soils every three to four years. The quality of seedbed preparations influences crop establishment for seed sown and module planted crops.
Poor seedbeds are characterised by large clods, areas of compaction, poor drainage and perennial weeds. Large clods affect crop establishment causing bare patches which provide areas for pests, such as slugs, to shelter and weeds to colonise. Planting crops in areas previously under grass will likely have higher populations of slugs and other soil borne pests. One method to reduce the amount of soil borne pests is to lightly roll seedbeds to firm the soil. Rolling also helps greenhouse soils that are regularly cultivated becoming ‘fluffy’. Such seedbeds with a very fine texture reduce root to soil contact that can lead to poor crop establishment.
Planting scented stock from modules in well prepared greenhouse soil
Good seedbed preparation also reduces the amount of weeds in the crop. A few weeks prior to planting, cultivate the soil to encourage weed seed germination. Once the weed seeds germinate control them using a non-residual herbicide. With minimal cultivation plant or sow the crop to ensure new weed seeds are not brought to the surface.
Some outdoor direct sown crops may be treated with residual herbicides to prevent weed seeds germinating. Always check the product label for crop suitability. If using residual herbicides good seedbed preparation, dose rates and timing are important to prevent crop damage. Note chickweed resistance to some sulfonylurea herbicides has been recorded in Northern Ireland for a number of years.
CROPS
Prepared by: Leigh McClean
e-mail : leighmcclean@dardni.gov.uk
telephone: 028 9442 6928
Winter cereals
After such a prolonged wet winter surviving crops are showing signs of stress as days lengthen, temperatures hopefully warm up and plants attempt to grow. Once water subsides and field conditions allow, winter crops will need their first nitrogen (N) application to breathe life back into them. Typically winter barley should receive one third of total N during late tillering, usually before mid-March. To promote tillering in thin barley crops aim to get on sooner or increase the proportion of N applied at this early stage. Research funded by ADAS has shown that modern winter barley varieties can produce bigger yields if a higher proportion of nitrogen is applied before stem extension. However if applying extra early N, it will need to be accompanied with a more robust fungicide and PGR programme to keep the crop standing and clean from disease.
For winter wheat a third of total nitrogen before the start of stem extension is sufficient, usually around the end of March. As with winter barley if the crop is late drilled, thin or struggling sow nitrogen earlier to encourage tillering. For all winter cereals this first fertiliser application is the ideal time to incorporate at least 20 kg per hectare sulphur and to top-up remaining phosphorus (P) and potassium (K).
Turning our attention to herbicides, prioritise winter barley as the few remaining grass weed herbicides effective for this crop only work on small grasses. Also cut-off dates for latest application are earlier than for winter wheat. Consult product labels carefully for cut-off dates and latest growth stages.
Disease control
Disease is already active in earlier sown crops of winter barley. These lush crops may benefit from a T0 fungicide to reduce pressure on the main T1 spray. All winter barley crops will require a robust T1 spray in late March or early April at GS 30-31 to control rhynchosporium and mildew. Keep dose rates high particularly if no T0 has been applied.
Similarly in lush winter wheat crops a T0 application of a protectant product helps reduce pressure on the T1 spray at GS 31-32 normally applied around mid/late April. If yellow rust is a threat addition of a triazole with good rust activity should help at T1.Further details to help plan your programmes, including growth stage charts and HGCA fungicide decision support charts can be found on the DARD crops homepage (www.dardni.gov.uk).
Spring barley drilling and Chlorpyrifos withdrawal
There is still time to soil sample fields before spreading slurry or farmyard manure. Soil sampling is money well spent; highlighting the P and K status of soils and lime requirements.
The only chemical control for leatherjackets, Chlorpyrifos will be withdrawn from 1 April 2016. In the absence of any chemical control pay attention to high risk spring barley fields where leatherjacket populations are high, particularly if old grass leys are being ploughed for the first time in a while. Minimise the risk of damage by drilling into a well cultivated, fine, firmly consolidated and warm seedbed where the crop can emerge quickly and grow away from the pest. Where leatherjackets are known to be a problem compensate for potential seedling losses with a higher than normal seed rate.
POTATOES
Early fertiliser
By now most fields intended for potatoes should be soil sampled. Where there is a high potash requirement it is advisable to apply immediately after ploughing, particularly if muriate of potash is the main source.
Seed preparation for planting
Attention to detail during handling and preparation of seed prior to planting can result in increased early tuber yield, whilst optimising fry colour and skin quality.
Carefully check the seed as it arrives on farm and have samples hot-boxed to determine the presence of disease and overall sprouting vigour. Treat seed with a fungicide pre-planting to reduce disease transmission and maximize marketable yield.
