Getting the grass right to make the cut

Ireland's biggest harvest will commence in a couple of weeks, with quality needed to keep the herd performing all year round

James Maloney

29 April 2017

Farmers are opting to ted out grass to increase quality and dry matter

Mowing in the evening time is generally accepted as the best time, as the sugar levels are at their highest. Teagasc believes that preparation is key to making good-quality silage. A sugars test should be carried out before you cut to check if the grass is fit for ensiling. Teagasc centres around the country will facilitate this; just bring in a sample of grass and they will do the rest. Once sugars are above 3%, the grass is OK for ensiling.

Mowing in the evening time is generally accepted as the best time, as the sugar levels are at their highest. Teagasc believes that preparation is key to making good-quality silage.

A sugars test should be carried out before you cut to check if the grass is fit for ensiling. Teagasc centres around the country will facilitate this; just bring in a sample of grass and they will do the rest. Once sugars are above 3%, the grass is OK for ensiling.

Sugars will increase if the grass is tedded out in fine weather.

Philip Cosgrave from IAS laboratories offers a quick turnaround on pre-mowing tests for silage. The test analyses nitrate and sugar levels to help make the decision.

High nitrate level will act as a buffer to pH, which can affect the lactic acid fermentation desirable for quality grass. Nitrate levels can be high where the application of N has not been fully utilised by the growing silage crop.

According to Philip, 80 units of N applied will typically take 40 days and one week before mowing. Higher DM grass will ferment at a higher pH. If the sample is in the lab by 12pm, the results are available that evening for farmers. The test costs are €20 for nitrates and €10 for sugars.

Heavy grass swards not tedded out will not reach their potential to wilt effectively in 24 hours. Ideally, the dry matter in the grass should be between 30% and 35% for baling. It is advisable that the mower swath boards are opened out to let the grass fall in wide rows between the wheel tracks. For haylage, the common saying is a day off hay and up to 60% DM is needed.

Mowers, rakes and tedders

Setting up the mowers, rakes and tedders is the primary objective of the operator. Machines that are cutting and raking soil are of no benefit.

The machines need to cover the ground effectively, not losing any of the grass crop, and also allowing them flow over the cut grass. Bumpy undulating fields cause difficulties in achieving this.

Mowing too tight to the ground can also have a negative affect. Again, the butt of the grass may have old material that may favour mould development in the bale. Also, tightly mown paddocks will take longer to regenerate grass.

The suspension system needs to be adjusted to allow the mower float.

Raking in grass into windrows for baling needs to be uniform, with no lumps. A consistent row in terms of grass volume and width will always make the best bales.

Survey shows science pays

Farmers are taking a more measured and scientific approach to their grassland, leading to reduced fertiliser usage, but there is still plenty more that they can do, according to new survey results.

Organised by the Grassland & Muck Event, the survey reveals that more farmers are analysing their soil and manure than ever before, with an increasing proportion also taking professional advice on variety choice.

However, there is still a huge opportunity for farmers to make more of their grassland, with only 14% regularly measuring grass growth and 29% still not producing a nutrient or manure management plan.

“The last time we conducted this survey was in 2011 and it’s encouraging to see how farmers’ attitudes have changed,” says Alice Bell, head of technical events and organiser of Grassland & Muck.

“Of particular note is a more scientific approach to manure and slurry usage: 14% of respondents now use laboratory analysis against 9% in 2011 and the proportion basing nutrient content on personal assumption has dropped from 37% to 20%.”

As a result, 29% of respondents have reduced nitrogen fertiliser usage, 24% are using less phosphate and 21% have cut potash applications.

“The cost savings from making better use of manure are considerable,” says Alice. “But it’s also interesting to note that between 15% and 19% of farmers have increased fertiliser use, based on soil analysis, to improve grass quality and yield.”

Even so, there’s plenty more that farmers can do to exploit the true potential of their grassland, warns Nigel Hester, area manager at Yara.

“Many are still not soil-testing frequently enough, measuring grass yields or investing in the best grass varieties where an effective balanced crop nutrition programme will help achieve high yields of nutritious forage.”

Some 70% of respondents admitted to never measuring their grass and 14% said they never tested their soils. However, on the plus side, 62% said they do test their soils every five years or less, with the majority reseeding leys every six years or less. “The top reasons for reseeding are poor silage crop or low yield (49%), rotation (37%) and weeds (33%),” says Alice.

Full coverage of silage '17