Teagasc issue dry weather advice for farmers

Teagasc has issue some dry weather advice to farmers that are starting to see the affects of the current dry spell on their farms.

Most parts of the country haven’t seen rain for a number of weeks, with farms on drier type land starting to see the impact the most.

Grass growth is severely affected when soil moisture deficits go above 60mm.

Based on Met Eireann information in the east of the country on the June 1, soil moisture deficits were 59mm – with these deficit still building.

Dry weather advice

Teagasc has offered some advice to farmers on how to handle the current conditions on their farms.

In terms of slurry spreading Teagasc are advising that if your ground is very dry and you see no real growth, there is no point in spreading.

The grass is unable to take it up, on a very dry sunny, windy day like what we are getting in the east, you are spreading on bare ground, the nitrogen portion of the slurry can be easily lost through volatilization, even using a dribble bar/trailing shoe.

It also presents a possible risk of burning of re-emerging grass under very hot and dry conditions. 

If you are further west where the soil moisture deficits are lower or have heavier ground with a grass cover and grass is still growing, you could spread watery slurry and spread in the cooler part of the evening preferably using a trailing shoe, to capture the nitrogen.

Fertiliser

The advice for chemical fertiliser is similar to the slurry in that it should not be spread on land that is very dry.

During a green drought, the best place for your fertiliser is in the bag – fertiliser is not limiting growth, it is moisture.

In the most part there is already fertiliser applied, that has not been used up.

Also, with the soil temperatures where they are, there will be plenty of nitrogen mineralisation from the soil.  

When the rain does come there will be enough nitrogen to kick off growth, once you are sure of increased soil moisture you can apply your fertiliser.

If 2018 thought us anything, it is you cannot depend on rain coming until it falls on your head.

If you have heavier ground and you still have some grass growth, you could apply your compound fertiliser.

This will provide your phosphorus (P) and potassium (K) and some nitrogen, if rain does not come you can graze this ground and not have wasted nitrogen.

If rain does come in the next 14 days, you can top up with your nitrogen and you will have lost no time

Teagasc are also advising that if rain is forecast, farmers should not spread fertiliser until after it rains.

There will be enough nutrients in the soil to kick off growth. You can then apply chemical fertiliser once soil moisture levels have increased or when the soil moisture deficit goes back below 55-60mm.

Grazing

Offering advice for grazing, Teagasc said that a lower pre-grazing cover may have to be accepted in some cases but every effort must be made to try hold a 25 day rotation.

With an average growth rate of 60kg dry matter (DM)/ha, a 23 day rotation is required to achieve 1,400 Kg DM/ha pre-grazing cover (i.e. 1,400 / 60 = 23 days).

However, as the dry weather continues it is unlikely that a growth of 60kg DM/ha/day will be achieved going forward.

If we look at the east at a current growth rate of 54 Kg DM/ha/day a 25-26 day rotation is required (see table below). 

Teagasc advise to try and keep at least 1,200kg DM/ha, growth will have to stay at 50kg DM/ha/day and the rotation length at 25 days (grazing 4% of the available grazing area/day, or 28%/week). 

If growth falls below 50kg/DM/ha, the rotation will have to be lengthened to 30 days.

Demand will have to equal or be lower than growth to maintain covers, this may require supplementary feeding  with hay/silage/concentrate.

The introduction of supplementation should be done before grass supply on the farm declines to a serious extent.

Below are some tips that can be used on farm to achieve your targets:

• Rotation length must be maintained at 24-25 days approximately. Effectively this means grazing no more than 4% of the grazing area daily. On a 100ac farm that’s 4ac/day;
• Keep in mind the DM of grass is high, so you will get longer out of paddocks;
• Graze down tight to 4cm, otherwise feed is being wasted;
• Assess the grass available on this area and if you are grazing more than 4%/day you should supplement with forage/concentrate to balance herd demand;
• For example, on 100 acres graze 4 ac/day, 28 ac/week, if you see you are grazing down to 4cm or less and exceeding the 4 ac/day you will need to supplement with silage, hay or concentrate;
• Reduce daily grass demand if necessary to below daily growth rates. This will help to hold grass cover on the farm, protecting current growth and speeding up recovery when rain arrives;
• Strip graze strong paddocks;
• Increasing rotation length beyond 30 days may lead to much reduced grass quality in current conditions (<50kg DM/ha/day grass growth).