Management Notes for April 2016

Date published: 6 April 2016

Dairying

Prepared by Michael Garvey
e-mail: michael.garvey@dardni.gov.uk
telephone: 028 3752 9054

Cows at grass

Last month I encouraged you to get your cows out to grass. Now that the time has changed your cows should be going to grass straight after morning milking and grazing for half a day. Aim to have your grazing rotation fully established by the third week in April. Full-time grazing will provide the nutritional requirements for cows yielding up to 25 litres.

Currently cows grazing for a few hours after morning milking are being topped-up in the parlour after the first 10 litres of milk at a rate of 0.45 kg of concentrate per litre. Once cows are settled on day time grazing restrict parlour feeding to cows giving more than 15 litres. Full-time grazing with 7.5 kg of parlour supplementation provides the nutritional requirements for cows yielding up to 40 litres. Cows yielding above 40 litres should still have access to blend in a TMR.

The table below shows a practical spring transition:

The typical performance of the farms I work with in Armagh during April has been:

I will be encouraging these farmers to:

• get cows grazing
• gradually get more grass into cows
• change their parlour M+ as cows move to full-time grazing
• have their grazing rotation fully established by the third week in April

Drinking water

As a rule of thumb cows require five litres of water for every litre of milk produced. As about half of the herd’s daily water requirement is consumed after each milking it is important to provide adequate trough capacity and water flow rates to meet demand. Any restriction in water supply will affect milk yield. Provide enough trough space for 10% of the herd to drink at any one time and 700 mm of trough space per cow drinking. Position troughs in the grazing area to avoid yield restriction. The lip of the trough should be 850 mm above the ground and the water level 50-100 mm below the lip.

Laneways

Cows will make approximately 600 journeys to and from the field to the milking parlour this grazing season. Well maintained, wide laneways allow easy movement of stock. If cows are allowed to walk at their own speed they can pick their way along poor tracks. However if cows are under pressure they will not have time to negotiate sharp stones, holes or tight turns. Keep an eye on cows as they walk to identify lame cows. Treat lame cows immediately and improve damaged lane surfaces.

Nitrogen for silage

A splash-plate application of 33 cubic metres per hectare (3000 gallons per acre) of cow slurry during February or March will have supplied enough phosphate and potash for first cut silage at typical silage field soil indices. It will also have provided some nitrogen (N) for grass growth. As there is still a major requirement for N fertiliser apply a further 100 kg of N per hectare (80 units per acre) to silage fields.

Beef and sheep

Prepared by Darryl Boyd
e-mail: darryl.boyd@dardni.gov.uk
telephone: 028 9034 0957

Getting cattle out to grass

Now we are into April your thoughts will be turning to getting stock out to grass. Aim to turn cattle out when grass covers are adequate. As a guide this is when there is about two weeks supply of grass in front of them. Avoid keeping cattle housed until there is an oversupply of grass as this can quickly lead to more difficult grassland management.

Most of you will by now have sown N fertilizer on grazing areas and will be seeing the benefits of slurry applied in mid March. Urea fertiliser is the most cost effective form of N and can still be used where there is some grass cover and suitable moist conditions. In areas of low grass cover and drier conditions it is preferable to use other forms of N.

Close up land for silage production

If planning to cut silage at the start of June it is important to remove grazing stock from this land early April. Don’t be tempted to graze this land too tightly (under 5cm) before closing up for silage as this could potentially reduce grass growth rates and silage yields.

Protect against Grass Tetany

After turnout a major concern with suckler cows is Grass Tetany (‘staggers’) which is due to magnesium deficiency. As well as lactating cows it also can affect ewes and is often associated with high potash applications from fertilizer and slurry, particularly on soils that are already high in potash. The risk is greatest for animals under stress as a result of unpredictable weather and change of diet at this time of year.

Prevention involves ensuring animals have a daily supply of magnesium. This can be provided by:

• adding magnesium to drinking water while making sure no other sources of water are available
• dusting magnesium (calcined magnesite) on the grazing pasture.
• treating with magnesium boluses
• offering a 50:50 mix of calcined magnesite and molasses. Approximately 2.5 kg of the mix provides for 20 cows on a daily basis. Keep the mix stirred and top-up regularly
• magnesium licks or blocks and/or feeding a high magnesium meal daily

Young cattle

Young growing cattle benefit most from an earlier start to the grazing season and can be turned out when grass covers are lighter (1900-2000 kg dry matter per hectare (7-8 cm high). Start at a low stocking rate of 1000 kg per hectare.

Suckler cows

Suckler cows and calves should be on grass when ground conditions allow and ideally when average grass covers are 2200 kg dry matter per hectare (9 cm).

Rotational grazing

For most beef and sheep farms, moving stock every three days achieves efficient grass utilisation. This means for a 21 day rotational system, six to seven grazing areas are recommended. To manage grass covers efficiently you need to know how much grass is left on the grazing area on a weekly basis. In the early part of the season this can be achieved by grass measurements and by assessing the grazing days ahead. The grazing days ahead should be within the range of 12-15 days. The stocking level depends on sward quality, growth rates and soil fertility levels. The table below provides a general guide on stocking levels:

Guide to stocking levels and sward covers April to July (assuming an annual application of 150 kg N per hectare)

Stocking rate

Overstocking reduces grass growth and livestock performance. Understocking may maximise livestock performance in the early part of the grass year. However sward quality quickly deteriorates as the season progresses resulting in poorer utilisation and reduced livestock performance later in the year.

Horticulture

Prepared by Kieran Lavelle
e-mail : kieran.lavelle@dardni.gov.uk
telephone: 028 3752 9060

Slugs in emerging crops

Slug populations increase significantly in wet, mild weather. A higher risk of damaging populations occurs in:

• moist heavy clay soil
• seedbeds with clods or minimum cultivation
• soils containing farmyard manure or organic material
• ploughed land cover such as grass

Seeds and seedlings are particularly vulnerable to slug attack. Before sowing or transplanting, place baited slug traps containing layers mash (not slug pellets) to monitor slug numbers. Leave traps overnight and check the next day. Thresholds for starting treatment depends on the type of crop, for example one slug per trap in a vegetable crop means control treatment is necessary. Seedbed preparations are very important in reducing slug numbers to a manageable level. Other controls include:

• removing weeds or other host vegetation
• firm seedbeds to restrict slug movement
• ensuring good seed/transplant and soil contact to encourage quick crop establishment

Two different types of slug pellet products are available which have different chemical formulations; ferric phosphate and metaldehyde. Ferric phosphate is a chelated iron product and is more environmentally friendly. When using ferric phosphate pellets slugs usually die underground rather than on the soil surface so no visible signs are evident. Metaldehyde is also effective but take care to apply it in the correct conditions as it can persist in drinking water. For more information on metaldehyde rates and application best practice check out www.getpelletwise.co.uk.

If you apply slug pellets you are legally required to have a Certificate of Competence in the Safe Use of Pesticides. CAFRE are planning to deliver two PA4S (slug pellet application) courses on 31st May and 1st June at Greenmount Campus. If you, or someone from your business, are interested in attending the course please enroll at http://bit.ly/1Uat7Pg.

Soft fruit update

Lori Hartman, Edible Crops Development Adviser, and three soft fruit growers from the Armagh area attended a recent Soft Fruit Information Day in Inchture, Scotland. This event was hosted by the Scottish Society for Crop Research and Bulrush. Some of the main points delivered by researchers from the James Hutton Institute, AHDB and commercial companies are detailed below:

Spotted Wind Drosophila (SWD) update (James Hutton Institute)

This fruit fly pest has been making its way across Europe since it arrived from Asia in 2008. Unlike other Drosophila sp., SWD females lay their eggs in ripening fruit (as opposed to over-ripe fruit). This species poses a threat to a range of soft fruits and soft skinned stone fruits. Appropriate monitoring is crucial in detecting the pest before infested fruit goes to market. Crop and site hygiene are more important than ever to reduce breeding and overwintering opportunities. This pest will be monitored in Northern Ireland as part of the CAFRE soft fruit Business Development Group.

New strawberry varieties (EMR/AHDB)

Strawberry ‘Elsanta’ is the current market favourite, with its sweet, firm, medium to large berries. Researchers at East Malling and AHDB have identified the new selection ‘Malling Centenary’ as having the potential to surpass ‘Elsanta’. One improvement is the simplified flower truss which produces five to six flowers per truss, allowing for larger and more uniform berries. Over four years of trials, ‘Malling Centenary’ consistently came out on top for berry appearance, flavour, colour, uniformity and shelf life.

Understanding crop physiology to optimise feeding options (Omex Agriculture)

Calcium (Ca) is an important nutrient for strawberries but applying a foliar feed at the wrong time is a waste of time and money. For Ca to be absorbed into a cell it is exchanged with auxin. Strawberry ripening is triggered by a reduction in auxin. Therefore, a ripening or ripe strawberry cannot absorb Ca because it does not have the auxin to exchange within the berry cells. Timing for additional feeding needs to be carefully considered when Ca is involved.

Crops

Prepared by Leigh McClean
e-mail: leighmcclean@dardni.gov.uk
telephone: 028 9442 6928

Cereals

Winter cereal

Most winter cereals are due the second application of nitrogen (N) at early stem extension (growth stage 30-32) with barley normally reaching this stage before wheat. If not supplied by the first application, aim to include sulphur at a total rate of 25-40 kg per hectare of SO3 for all cereals. Where applied, organic manures may have supplied some of this requirement and should be taken into account. Inspect crops for recently emerged broad leaved weeds and apply top-up herbicide to any problem or late germinating weeds as soon as conditions allow. To avoid unnecessary crop damage adhere to product labels, paying particular attention to latest application timings, sequences with other herbicides and safe tank mixes with other products.

Disease control

In winter barley, especially where no T0 fungicide has been applied or T1 is yet to be applied, fungicide rates need to be kept high to help get on top of any infection in the crop. Following T1 fungicides, the next main spray is the T2 which should be applied around growth stage 39 when the flag leaf has fully emerged and the first few awns are appearing. It is very important to ensure the gap between T1 and T2 fungicide applications does not exceed four weeks. Fungicide options are similar to T1 sprays and again rates will depend on disease levels at the time of spraying.

For winter wheat some crops will have received T0 sprays by now. Where this has not yet been applied the T1 will be critical to get on top of Septoria and should be applied around growth stage 32 or ideally leaf three emerging. For the T1 use robust rates of Triazole, for example Ignite or Proline mixed with an SDHI and multisite protectant. Links to HGCA fungicide decision support charts can be found on the crops page of the DARD internet site (www.dardni.gov.uk) along with growth stage charts to help plan your programmes.

Spring barley

Sowing should take place as soon as a good seedbed can be created. The chosen seed rate, calculated from the thousand-grain weight, should lie between 350 and 400 grains per square metre.

Plan also to treat weeds in emerging crops as soon as possible. Earlier treatment allows the use of a wider range of products helping manage resistant broad leaved weeds and also target annual meadow grass.

Potatoes

Sprouting and chitting

Pre-sprouting systems (bag or tray) must provide adequate temperature, ventilation and light to control sprout growth and protect against frost. Seed planted now will be for the main crop so ensure the pre-sprouting system encourages multiple sprouting to produce many tubers which can increase in size over a longer growing season than with early varieties.

Mini-chitting

This system of seed preparation aims to produce seed tubers with sprouts no more than 2 mm long. Seed is stored at 3-4 oC until seven to 10 days pre-planting when the refrigeration unit is turned off allowing chitting to occur. Plant seed once 1-2 mm sprouts have formed. If planting is delayed re-cool seed to 3-4oC preventing further sprout growth. Although later harvested than pre-sprouted seed, mini-chitting produces a crop that emerges quickly and evenly.

Greening and EFA requirements

In 2016 some growers will again have to meet greening regulations. Crop diversification remains the same as 2015, the two and three crop rules still apply.

If you still have an Ecological Focus Area (EFA) requirement you must ensure that an area equivalent to at least 5% of arable land is used as an EFA. This is the same percentage as in 2015. The big change from last year is that the EFA declaration must be submitted online in 2016, the new system will be available from early April.

Greening represents approximately 30% of your entitlement value so it is worth taking time to make sure you have made allowance to cope with it.