Winter crop technical update

Author: George Blackburn 


As we move into the second half of February and look towards the beginning of March, our attention must first focus on the winter crops in the ground from autumn 2021. Key management decisions regarding fertiliser and growth regulation in the early stages of spring can have a major bearing on a crops final yield potential especially winter barley.

There is a slight increase in the overall acreage of winter cereals as sowing conditions were good in the early part of autumn 2021, with many growers opting to drill a little earlier to get crops established. The sense of optimism amongst growers following last year’s exceptional harvest was a welcome boost to the sector and as a result, growers were eager to get crops planted. The earlier drilled crops have better establishment without question and did receive an autumn aphicide. Those that took the gamble of sowing earlier into better conditions seem to have been rewarded so far but time will tell on this. The winter has been a lot milder than normal so many early drilled crops are quite advanced in terms of growth stages. Growth regulation and delaying applications of fertiliser on these earlier crops will be wise this spring. The huge increase in fertiliser prices has tempered some of last year’s optimism, however, grain prices look very strong for the coming harvest and many growers have availed of attractive forward prices. When planning fertiliser strategies for the coming season regardless of price, the focus must be on growing a crop to its full potential. This has always proven to be the most profitable strategy. Soil sampling and correct liming are key steps required to produce optimum yielding crops for the coming season.


Winter Barley

Winter barley crops have established well, with good plant count levels. Most were sown in ideal sowing conditions and have come through a very dry winter. Some of the crops are a little bit forward, with some live disease in them and will require robust growth regulation programmes. Any crops that have not received any Phosphorus (P) and Potassium (K) will need an application before the end of February as soon as conditions allow. Crops that received no autumn P and K will start to show up deficiencies especially for P when temperatures pick up and growth kicks in.
Check your soil samples and tailor NPK compounds accordingly. As a rule of thumb, winter barley crops need 30-35 units of P and 100 units of K. This will vary slightly between 2 row and 6 row varieties, with slightly higher potash requirements for the 6 rows. Aim to have 75% of Nitrogen (N) out on winter barley by March 20th. Disease levels are generally low, growth regulation and tillering will be the main focus of early chemical applications. Do not be tempted to drop back on P and K applications too much as we must remember that offtakes from fields were very high last harvest.


Winter Wheat

Winter wheat crops are generally good but there is some variation out in the fields. Crops sowed earlier that are well established are in good heart, with excellent plant stands. Crops sown later in difficult seedbeds, especially potatoes and fodder beet have suffered a bit with crow and slug damage. Chopped bean straw has also proven to be a suitable host for slugs and a few winter wheat crops after beans have needed to be treated with slug pellets. It is becoming increasingly more important to run a shallow disc over chopped bean or rape straw and is an important part of the Straw Incorporation Measure for slug control. Our methods of chemical control are no longer as potent as they used to be. Many crops after beans have a lot of volunteers coming through but these will be easily dealt with in the spring and are actually serving a useful drainage purpose at the moment by soaking up moisture from the soil.

While crops are generally good and winter wheat has an amazing ability to compensate for sub-optimal plant stands at harvest, I would be reluctant to tear up any crops bar they are very poor. Aim to have a balance of P and K out on wheat by mid-March. Apply according to soil sample requirements. Aim to have the first main split of nitrogen on by the first week of April and final split on the first week of May. It is important to remember that wheat should not have too big a canopy too early in the crop, as this presents problems for growth regulation and disease control, especially Septoria Tritici.


Winter wheat field

Winter Oats

Winter oat crops have established well in general and there is a nice amount of winter oats in the ground. The two varieties sown are Isabel and Husky, both spring varieties sowed in the autumn. Most crops are in good condition but some in the more coastal and milder areas are a touch forward. These crops will need careful attention in terms of growth regulation and rust control especially in south Wexford and other coastal areas. Crops will need to get their NPK requirements by the middle of March with a blend such as 10-5-25 plus S for winter oats at a rate of 4 bags/acre.


Winter oat field


Winter Oilseed Rape

The acreage of oilseed rape (OSR) has seen a drastic increase this year, owing to record prices available for the crop. Crops are in excellent condition and are more forward than ever after the mild winter. The Green Area Index (GAI) of each crop is worth measuring this year and there are a few useful apps available to measure this. Some crops have up to 3.5 GAI readings and are exceptionally forward. The key message for these crops would be to delay N applications for as long as possible and also to reduce overall N applied. Most crops are in the range of 2-2.5 GAI which is excellent coming out of the winter and there is an opportunity to reduce N applications by 50-60 units on these crops.

Pigeon damage doesn’t seem to be much of an issue at all this year. All crops received some P at planting and this has made a big difference to rooting and overall establishment. All crops have been treated with a fungicide for light leaf spot in the autumn and with Kerb (propyzamide) for grass weed control. Most crops received an autumn growth regulator which seems to have worked very well to even out crops for nice canopy management in the spring. As a result, crops have nice clean canopies for the onset of spring. Aim to get potash out on OSR by mid-March, 100-110 units is sufficient. Rape has a high requirement for Sulphur (S) so the first main split of N should include ASN (26% N + 14% S), with further applications of Sulcan. Aim to apply the last 40-50 units of N on rape at the latest possible time that the fertiliser spreader can physically travel through the crop.

Winter oilseed rape


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Herbicide resistance in tillage farming

Author: Jimmy Staples


Over the last decade, it has become increasingly difficult to manage some of the pests that we were previously able to control comfortably with plant protection products.

This can be attributed to:

  • The loss of key active ingredients due to de-registration
  • A lack of new active ingredients coming onto the market
  • The development of resistance to the current active ingredients on the market


Loss of active ingredients

The loss of active ingredients is a worrying trend and according to the DAFM website, there were 17 active ingredients whose registration was revoked between December 31st 2018 and August 23rd 2020. The last date for use of many of these active ingredients has now passed with the loss of chlorothalonil (Bravo) and the neonicotinoid family of insecticides creating big challenges.


Resistance in the tillage field

This loss of key active ingredients is compounded further by the development of herbicide resistance. BYDV control can be challenging due to pyrethroid resistance within some species of aphids. Diseases like Septoria are constantly putting available chemistry to the test and resistance to herbicides is becoming increasingly common throughout the country.

We have both broad-leaved and grass weed resistance confirmed here in Ireland and it is suggested that this is under-reported. Here in Wexford, I have come across resistant populations of chickweed, corn marigold and wild oats and I am currently awaiting results from Teagasc in relation to populations of blackgrass and Italian ryegrass which may also be resistant.


Reported weed resistance to one or more herbicide - table


Cultural control: Integrated Pest Management 

The Enable Conservation Project has confirmed herbicide resistance in Italian ryegrass, blackgrass and wild oats. Blackgrass and Italian ryegrass populations have been found to be resistant to ALS herbicides (Alister Flex, Pacifica Plus, Broadway Star, Monolith), ACCase herbicides (Axial Pro, Falcon, Stratos Ultra) and in some instances, a combination of both. Where both ALS and ACCase resistance are present, it severely limits your crop herbicide options.

In these cases, Integrated Pest Management (IPM) strategies need to be to the fore and there are many options available. These include but are not limited to:


  • Use of rotations
  • Cover crops
  • Companion cropping
  • Arable grass margins
  • Using competitive cultivars
  • Pushing back sowing dates
  • Increasing seeding rates
  • Stale seedbeds
  • Cultivation type and depth
  • Establishment system
  • Rogueing
  • Crop destruction
  • Remote sensing
  • Monitoring and evaluation

A successful IPM strategy will consist of a number of these measures chosen specifically to meet the challenges of an individual’s farm and should be used along with the targeted application of herbicides. These should be implemented in a structured fashion over the course of the whole rotation. Achieving effective control of many of these weeds will not be possible in one, two or even three years.


Herbicide resistance management strategy 

Prevention of course is better than a cure and there is simple, yet effective measures that we can take to try and ensure that herbicide resistance does not evolve on farm. Most of these measures will revolve around the use of and application of herbicides.

When spraying, consider the following as part of a herbicide resistance management strategy:

  1. Has the target weed(s) been identified correctly?
  2. What is the target growth stage and when is the weed going to be at this stage?
  3. What volume of water do I need to use to ensure sufficient coverage?
  4. Do I have issues with the pH in the water I am using?
  5. What rate of herbicide do I need to achieve control of the weed(s) at the target growth stage?
  6. Try to keep tank mixes as simple as possible, so as not to stress the crop and ensure that all components of the mix work effectively. 


Some things are outside of our control. The last two springs have been incredibly challenging with weather conditions either too wet or too cold and the variations in day and night-time temperatures meant spraying days were very limited. I came across a number of cases of wild oats and sterile brome which were not controlled by herbicides in both 2020 and 2021. Samples were sent for resistance testing and results have shown that they were not resistant to the products used. A number of factors contributed to the lack of control, namely, big variations in day and night-time temperatures, shading from the crop and the use of lower rates of herbicide than was required.

It is important to understand the weeds on your farm as this will help you to decide on management strategies. For instance, it can take from five to ten years for resistance to develop in a population of wild oats as opposed to a population of blackgrass where resistance can develop in just three generations.

If you do suspect herbicide resistance on your farm, please get in contact with your advisor as the earlier the problem is diagnosed and action is taken, the greater the chance of a positive outcome.


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Promoting early calf husbandry

Author: John Bass 


Calf husbandry and nutrition are very topical at this time of year with many dairy and beef farmers rearing calves by hand on whole milk or milk replacer. Getting calves off to a good start is critical for their development, their feed conversion efficiency and also their subsequent production. Getting dairy heifer calves off to the correct start in life will not only maximise output but will also increase their longevity within the herd.



It is important to follow these simple steps as soon as a calf is born to ensure calf health and thrive:

  • It is important to give a newborn calf 3 litres of colostrum within the first 2 hours of life.
  • Ensure the first feed is the first milk from the cow after calving.
  • Check colostrum quality using a refractometer as quality varies from cow to cow.
  • Ensure a calf receives an adequate quantity of quality colostrum as it will provide the required antibodies and immunoglobulins to help boost the calf immune system.
  • Bottle feeding is often the best way of ensuring the calf has received an adequate volume.
  • If you are storing colostrum in the fridge, ensure a temperature of 4°C. Store it for no longer than 2 days as the level of antibodies declines rapidly thereafter.
  • When freezing colostrum, do so in small packs for ease of defrosting. Defrost slowly on a low heat below 50°C so you don’t reduce the number of antibodies.


Newborn calves drinking milk replacer from milk bar


Milk Replacer Vs Whole Milk 

It is advantageous to feed milk replacer after day 2 or 3 as it minimises disease spread when compared to whole milk. Calves require approximately 13% of their bodyweight in feed intake in the first week of life, which should be split between 2-4 feeds per day. In week two, this requirement increases to 15% of their bodyweight equating to about 6 litres per day for a 40 kg calf. Calves at 2-3 weeks of age have the potential to achieve 750-950 grams of live-weight gain per day, with a minimum target of 500 grams. Feed conversion efficiency is almost at 1:1 so the quality of milk fed must be high enough to ensure the daily intake is providing enough energy to meet demand.

Milk powders can vary in quality; skim or whey are more favourable than those based on vegetable proteins as they are more easily digested by calves. Like with whole milk, milk replacers need to be mixed and fed at the correct temperatures (37-39°C) and the correct concentration to ensure adequate nutrient intake. Aim for powders with a minimum of 23% protein and 17% fat and below 0.1% fibre. Mix 125 grams powder with 850mls of water which provides 1 litre of milk replacer. Feed 6 litres of milk per calf per day, this volume can be increased to meet demand if necessary.



It is important to introduce a high-quality ration or nut from day 2-3. Ensure it has a high cereal grain content and is highly palatable with no dust. Initial intakes will be small so keep quantities low and fresh. Early intake of cereal-based feed will rapidly increase the rumen development of the calf and the growth of papillae on the rumen wall, which will increase nutrient uptake capacity of the calf throughout its life. Failing to feed concentrates at an early stage will have drawbacks later in life. Aim to have calves consuming 1kg of concentrates at weaning.

Keep feed fresh and easily accessible in order to increase intakes from an early age. A high-grade nut can be advantageous as it is cleaner with less dust than a coarse ration and less attractive to birds which can bring harmful bacteria and diseases into sheds.

Claves at the feed barrier with concentrates



A fresh straw bed is important for calf comfort and health and it will also encourage fibre intake which will aid rumen development. Ensure calves have adequate feeding and resting space and that pens are well drained and ventilated. Regular cleaning and liming is a must to reduce the risk of any scours or other illnesses. Ensure there is a constant supply of fresh clean drinking water and that feeders and drinkers are at an accessible height for calves also.

A bright well-ventilated shed with no draughts at calf level is essential to avoid calves getting cold. Good ventilation will also ensure enough airflow above calf level to minimise respiratory problems and keep the air fresh.

Calves housed indoors


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NEW – Terra Range brochure available to download

Target Fertilisers are committed to the future of agriculture in Ireland through fertiliser and sustainable fertiliser usage. They are constantly looking at methods of maximising production through environmentally friendly and efficient uses of fertiliser. As a result, they have joined forces with Brandon Biosciences to develop a new range of sustainable fertiliser products, the Terra Range.

To learn more about the new Terra Range and how it can benefit your farm, download the new brochure here:


Terra Range brochure

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SlurryBugs®: Treating slurry more important than ever

Author: Philip Kennedy


In recent years, farmers are becoming increasingly aware of the benefits of treating slurry, however many have yet to make it a part of their nutrient management tool.

There are many slurry treatments on the market, however in this article, we will look at SlurryBugs® ; what it is, how does it work and what are the benefits of using it on farm?


What is SlurryBugs®?

SlurryBugs® is a bacterial slurry additive which breaks down the solid content producing a more homogenous and nutrient rich fertiliser.

It contains soil originating bacteria, enzymes and micro-nutrients which enhance the retention of nutrients within stored farm slurry. This can lead to significant savings on chemical fertilisers and enhance soil quality as well as reducing ammonia odour and losses.


How do SlurryBugs® work?

Slurrybug product packaging

  1. The bacteria retain nitrogen by capturing the ammonia within the urine. The nitrogen is fixed into a slow-release form of organic nitrogen which is readily available for plant uptake.
  2. The enzymes actively degrade the undigested fibre within the effluent which improves the consistency and reduces odour.
  3. The micro-nutrients provide a vital food source for the bacteria allowing more nutrients to be retained by the bacteria in an organic form.


CF - SlurryBugs Stats

Analytical results of SlurryBugs® part 2


What are the results?

A demonstration of the flow of organisms, nutrients and chemicals known as the BioCircle

  • Reduces odour

Most slurry odours are caused by ammonia being released into the atmosphere. When SlurryBugs® are used in conjunction with LESS (Low Emission Slurry Spreading) slurry application methods, there is almost no odour released from the slurry spread on the land. This is a result of fewer gases building up as the bugs increase nutrient retention.

  • Reduces fibrous crust

SlurryBugs® will reduce crust formation on top of the slurry, leaving it consistent. This will reduce agitation times and lead to less blockages, especially when spreading with LESS equipment.

  • Minimises need for stirring

After a few years of use, the bugs will build up in the tank and the need to agitate will reduce and slurry will stay homogenous for longer. This will mean a fuel saving up to 25%.

The continued use of the product will improve microbial activity in the slurry and the soil. The slurry pH will be raised to allow soil bugs to work at optimal. Microbial activity is greatly reduced in acidic untreated slurry.

  • Improves fertiliser value

Nitrogen availability and retention can increase up to 50% in treated slurry. This combined with LESS application methods can greatly decrease ammonia losses and therefore increase the amount of nitrogen used from slurry application. With all the above combined a typical 2,500 gals per acre application rate of slurry in spring should give you 25 to 33 units per acre of nitrogen. The nitrogen in this example is worth approximately €35 per acre.



How to apply SlurryBugs®?

  • Each 1 kg pot treats 100,000 gallons (450,000ltrs).
  • The product should be applied when slurry levels are low in tanks and at least 4-6 weeks before spreading to allow the bugs to work and multiply.
  • The slurry bugs can be mixed in a bucket of lukewarm water and then poured into lagoons, channels or directly into the tank.


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