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Green Acres Calf to Beef - GrowthWatch: Taking an opportunity to apply the ‘forgotten fertiliser’

Green Acres Calf to Beef - GrowthWatch: Taking an opportunity to apply the ‘forgotten fertiliser’

Historically, Irish farmers applied lime on a little and often basis. Now only 50% of the national lime requirement is applied. Lime corrects soil pH, grows more grass and improves how the soil uses Nitrogen & Phosphorus fertilisers. Seán Cummins GreenAcres Advisor encourages Lime application now

To quantify the situation on lime spreading nationally, work from Teagasc Johnstown Castle shows that only 50% of the national lime requirements are being applied. This is a worrying trend when the first step in correcting soil fertility at farm level is to correct soil pH.

The first step in correcting soil fertility on farm is to correct soil pH

Apply lime to grow more grass

Not only does a sufficient liming programme move pH levels to the optimum of 6.3 for grassland soils, it has the ability to make soil phosphorous more readily available, while also improving soil’s nitrogen use efficiency. To put this simply, correcting soil pH will grow more grass. Where soils are acidic and a liming programme is implemented research has shown that grass production is increased by 1t DM/ha. To quantify this increase into more understandable terms, it essentially means that correcting soil pH will generate the equivalent of 2 bales/ac of silage each year in extra grass.

On many farms, the timing of lime applications tends to occur in the backend of the year. Although there are years when this has worked, too often rainfall scuppers the best of plans and the opportunity to correct soil pH is missed and the problem rolls on into the year ahead. Given the weather experienced over the past three weeks, where even some of the most challenging ground is trafficable, there’s an opportunity to get out and apply lime on the basis of soil tests results.

Lime - when, where and how

Not only can lime be applied on fields where first cut silage ground has been completed and a second cut is not required, but it can also be spread on recently grazed paddocks with covers below 800kg DM/ha.

Mark Plunkett, Teagasc Johnstown Castle, has recently completed a lime factsheet, which provides further details on when, where and why to apply lime.

greenacres greenacres

Ciaran Bartley and Peter O' Hanrahan

Ciaran Bartley, Caherconlish, Co. Limerick  

  • Average farm cover: 1,204 kg DM/ha
  • Growth: 109kg DM/ha/day
  • Demand: 60kg DM/ha/day
  • Stocking rate: 5.28LU/ha  

Growth rates have improved greatly over the past two weeks, reaching 109kg DM/ha/day over the last seven days. Demand on the farm is currently running at 60kg DM/ha/day, so we are well any truly in a position of surplus grass.

The heaviest paddock on farm currently has a cover of 2,750kg DM/ha and will be taken out for bales over the coming days, with the next heaviest cover being 1,400kg DM/ha – ideal for grazing.

The paddock targeted for surplus bales this week will be the second to have been cut over the last two weeks and when omitted from the wedge, it drops our average farm cover to 1,042kg DM/ha.

Although this is a fraction high for the time of year, I will monitor growth rates closely over the coming days and if any paddock steps above the 1,400-1,500kg DM/ha mark, it will also be targeted for bales next week. By leaving a few days in between surplus cuts, it will avoid us flattening the wedge completely, while also keeping quality grass ahead of stock.

Applying Lime. Earlier this spring, we applied 120t of lime on grazing ground when conditions allowed; an additional 40t will be applied over the coming weeks to correct soil pH on farm; all of which was applied at a rate of 2t/ac.

Just 35% of the land here is at optimum levels for soil pH. By taking the opportunity to apply lime now means we are not battling against the elements or rainfall later in the year, which often leads to some of our land becoming inaccessible for heavy machinery.

Peter O’Hanrahan, Thomastown, Co. Kilkenny

  • Average farm cover: 795kg DM/ha
  • Growth: 54kg DM/ha/day
  • Demand: 43kg DM/ha/day
  • Stocking rate: 4.8LU/ha

With growth rates improving and 40ac of silage ground coming back into the grazing rotation, we made the decision to spray off 20ac for reseeding. Half of this ground has covers over 2,000kg DM/ha and will be harvested in the form of bales, while the remainder will be grazed.

With rain forecast for the weekend ahead, this ground will be stitched with a mixture containing varieties high on the Pasture Profit Index and will be rolled immediately after seeding. Clover will also be included and a clover-safe spray will be used as a post-emergence spray.

Stitching has worked well in terms of pasture rejuvenation here over recent years, as it reduces the period between grass establishment and grazing as only the surface of the ground is cultivated in the stitching process. To provide the new grass seeds with the best possible start, three bags of 10:10:20 will be applied at sowing.

In addition, just over 3ha of surplus bales were removed last week. Keeping appropriate grass covers ahead of stock this time of year is critical to maintaining animal performance. By last week’s surplus bale removal and the planned reseeding this week, we will have reduced the farm cover significantly and this will allow us to maintain quality grass ahead of stock over the coming weeks.

Drafting of third season cattle has also commenced on farm, with the first batch of 16 slaughtered last Friday and a further 16 will be moved next week. Angus steers last week achieved a 300kg carcass at a carcass conformation of O=4- at just over 26 months of age.

To find out more about the Green Acres Calf to Beef Programme click here https://www.teagasc.ie/animals/beef/demonstration-farms/green-acres-calf-to-beef/