Farm Ireland

Wednesday 13 December 2017

Drill fertiliser and seed combination the best option in low fertility soils

The Sumo DTS strip till drill
The Sumo DTS strip till drill
Host farmer Paudie O’Brien with Ger O'Sullivan and Ger Courtney, Teagasc at the Teagasc Spring 2017 farm walk at Firies, Co Kerry in conjunction with Kerry Agribusiness. The key issues discussed were grazing, improving soil fertility, breeding management and sire selection. Photo: Valerie O’Sullivan
Pat Minnock

Pat Minnock

The good weather and soil conditions towards the end of March allowed some field work to proceed, particularly the sowing of spring wheat, beans and some barley.

Again, towards the end of last week conditions improved and significant progress was made with sowing.

At the moment it appears that the overall acreage of spring barley will be back on 2016, while bean plantings will struggle to reach the 12,000 hectares this season. Spring wheat and oats sowings will be well back.

As grain prices are likely to be poor again this harvest, it is important to try to maximise returns by good management and timeliness of work.

It is better, however, to sow in good seed bed conditions than trying to sow early in poor conditions. Crops will compensate if seed bed conditions are good at the time of sowing.

A week or two later sowing will have insignificant effect once conditions are right.

It is essential to know the fertility of your soils before you sow. If fertility levels are low - particularly if P and K are index one or two - it is best to combine drill fertiliser with the seed.

If combine drills are not available, the next best option is to try and apply your fertiliser as close to the seed as possible.

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Applying fertiliser just before the drill can achieve this. If fertility levels are low, waiting until you see the tram lines will significantly reduce your yield potential.

When sowing, good seed to soil contact is important.


Under GLAS many may have chosen to establish crops by min till and if this is the case you must ensure you min till the same fields each year of your GLAS contract.

In a season like this the min till option is very attractive particularly for growers of large crop areas, however it is essential that it is done correctly.

Min till will reduce your establishment costs, but if not done correctly it can lead to reduction in yields.

Min till generally entails sowing 70 to 110mm deep. If ploughing, try to plough as shallow as possible. If conditions allow, rolling is very beneficial.

Seed rates should be calculated based on the number of plants you want to establish and should take into account all factors encountered at sowing.

The thousand grain weight (TGW) and the expected establishment rate will affect the seeding rate.

For example, to establish 300 plants of spring barley/m2 with a TGW of 48 and an 85pc estimated rate of establishment, a seed rate of 169 kgs per hectare would be required (seed rate in kgs per hectare = target population x TGW / establishment percentage).

Earlier sowing produces higher numbers of tillers; consequently, later-sown crops need higher seeding rates to establish a higher plant stand.

The current target plant number for barley should be a minimum of 320 plants per m2.

An establishment of 90pccould be expected (in good conditions) so with a TGW of 50 a seeding rate of 181 kgs will be required. Late April sowing will require higher seeding rates again.

Crops sown from last week on will require an aphicide for barley yellow dwarf virus (BYDV) This should be applied at the three/four leaf stage.

If growing malting barley early nitrogen both in the seed bed and/or early top dressing is essential to maintain low proteins.

If growing barley for distilling, protein under 9.3pc will be required so late nitrogen or soils prone to good N mineralisation later in the season should be avoided.

It is now too late to sow spring wheat, beans and spring oats.

Some beans were sown last week and if you consider that it will be mid-October before these crops are fit for harvest sowing from now on leaves crops at a risk of not being harvested at all.

Most winter barley and wheat crops are at g.s. 30/31 while many oat crops are at 31/32.

The main split of nitrogen (approx. 50pc of total) should now be applied - approximately 70 to 100kgs per hectare on wheat and barley.

The final top dressing should be applied to oats bringing the total to 145kgs. The T1 fungicide is now required on barley if not already applied and should aim to control Rhynchosporium, Net Blotch and Mildew in particular.

Crops are relatively clean so, considering likely margins, costs can be minimised by using good value Triazole plus Strobilurin chemistry with the SDHI saved until T2.

Where mildew is present include a morpholine. A product of choice for many will be one of the many Prothioconazole products particularly where Rhynchosporium is present.

Many wheat crops are at growth stage 30 and could get a T0. It is still too early for the T1. T0 could be chlorothalonil on its own or with a morpholine if mildew is present.

A growth regulator (PGR) should be applied by g.s. 31. Options can include CCC, Meteor or Moddus or Meddax Max. A T1 will not be required until the third last leaf has emerged. Even in early-sown crops, this may not be for another two weeks.

Avoid Triazoles at T0 to minimise potential Septoria resistance developing. An SDHI with the addition of chlorothalonil should be used as the T1.

Most crops of winter oats are at g.s. 31 or even 32 and disease levels are variable. Mildew appears to be present in many crops. A PGR for oats is best applied at the second node, g.s. 32/33. The options can be CCC, Ceraide, Moddus or Meddax Max. The T1 fungicide can also be applied. This is generally products such as Tocata/Capalo.

The addition of 0.2L Talius per hectare is also useful for the prevention of Mildew later on.


Winter oil seed rape crops are in their full glory at the moment and are well advanced for this time of the year.

Most of these are beyond the stage for nitrogen and too late for PGR fungicide. If fields have grown rape previously Sclerotinia is a potential problem. The application of Filan at the start of petal fall is the most effective treatment for Sclerotinia control. Pollen beetles were relatively scarce this year. These are generally only a problem at green bud stage when the beetle burrows into the buds. If there are more than five beetles per plant control should be considered.

They actually help pollination once the crop is in flower.

Pat Minnock is a Carlow based agricultural consultant and a member of the ACA and the ITCA.

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