Treating grass as a crop boosts milk yields

Taking the time to create a crop nutrition plan for grass has paid dividends for a Wiltshire dairy farmer achieving more than 50% yield from forage.

Richard and Clare Sainsbury are tenant farmers at Round Barrow Farm, Pitton, Wiltshire. They milk 160 autumn-calving New Zealand and British Friesian cows on a predominantly grass-based system where slurry and soil analysis is essential.

Cows average 6,757 litres a year, with 52% (3,480 litres) coming from forage. They are only fed concentrates during the winter, and the clamp is made up of a sandwich of wholecrop (triticale mixed with rape and soya), grass silage and sugar beet, and brewers’ grains.

Mr Sainsbury says: “We have tried to create a system which works with the farm set-up and us having kids. The block-calving fits with the grazing management and it’s really flexible.”

And according to agronomist Simon Trenary from Countrywide Farmers, more dairy producers operating a grass-based system need to adopt the same mindset as the Sainsburys and start treating grass as a crop.

Grazing and grass varieties

The grazing system at Round Barrow Farm consists of intensively grazed long-term leys, some with white clover; three cuts of silage based on a high yielding Italian hybrid ryegrass variety with red clover; and 26 hectares of spring-sown triticale.

When the Sainsburys took on the farm in 2004, the soils were very depleted in phosphate and potash. Most of the farm has since been re-seeded, and maize has been replaced with spring triticale allowing the new leys to be established in good time for the autumn.

Richard Sainsbury said he tried to create a flexible system that was a good fit for the farm and his family.

In the past, grass varieties were predominantly intermediate with a large proportion of tetraploids. However, the mixtures used are now 20% tetraploid, with the remaining 80% being diploid.

Mr Trenary says: “Although tetraploids are very good and high quality, they do tend to go stemmy quite quickly. And on a system like this where we want a much more mouthy ley with a bit more bottom to it – the diploid provides that.”

He says the Sainsburys have also made a move towards using more late hitting varieties, and weed problems have been tackled by integrating red cover into the ryegrass mixtures.

“Cutting leys have been largely based on Italian varieties in mixture with red clover, but going forward this has been replaced with a hybrid based one. And, hopefully, the longer life-span of the hybrids will more closely match the productive life of the clover, improving the longevity of these leys,” he adds.

Mr Sainsbury says the grazing system is very similar to paddock grazing, and flexible in that first-cut silage aftermaths can come into grazing if necessary.

“Our cake usage has gone down by 10kg a cow and milk yield has gone up 9%. The forage quality is improving, and in the future we will try and reduce the amount of fertiliser we have to buy in even further, and increase grazing more,” he adds.

Triticale

A wheat rye cross, more commonly used on organic systems, triticale has been chosen by the Sainsburys as a replacement for maize.

Mr Sainsbury says: “We started growing triticale in 2006 because we found maize does not grow well here. It fits the bill from a crop point of view and from an animal point of view too, and it comes off at a good time to then put the grass leys in.

“We plant it at the beginning of March, and we get the grass in in September time so we have a good crop of grass for the silage. Triticale is drilled and the contractors are very precise because they use 30m tramlines.”

What’s more, he says the switch from maize to triticale has helped improved transition cow management.

“It’s in before the cows start calving and we are able to have the cows on a set ration when they calf. But before when we were growing maize we would have to have them on grass for the first month.”

In addition to the timing benefits of the crop, Mr Trenary says it is a good crop for use in a poorer soil system, has a higher amino acid profile than wheat or barley, and is also cheaper to grow than barley.

“We budgeted for 10t/acre and this year we have achieved 13t/acre,” he says.

Crop nutrition

Crop nutrition planning at the start of each year is crucial to the success of the grazing system at Round Barrow Farm.

Mr Trenary says: “We do it completely like we would do an arable business, and we come up with the plan on what we are going to feed the crop for the year.

“Slurry analysis is used to more accurately incorporate farmyard manure (FYM) into the programme, with slurry now injected both in the spring and into silage aftermaths. And the programme is tweaked as we go through the season, according to farm requirements.”

With regards soil analysis, Mr Trenary says: “If your indices are fairly stable then testing the soil every five years is good enough. But if you are moving a lot of muck around or if any indices are moving around, I would suggest doing it once every four years. When you look at the cost of fertiliser now, it makes sense to make sure you apply it right.”

Once a crop nutrition plan has been devised, a copy is shared with the contractor who carries out all the muck spreading, fertiliser application, silaging and harvesting – this close communication is essential, says Mr Sainsbury.

So why should dairy farmers change their attitude to grass management?

Mr Trenary says: “Paying more attention to slurry and fertiliser use actually saves you money in the long run – even though we are taking away more grass, we are still able to buy less fertiliser. For example, last year we bought 67t of fertiliser but this year we will only need to by 60t.”

Key Pointers

• Carry out soil analysis tests every four to five years to ascertain mineral levels in the soil
  
• Similarly, carry out slurry analysis tests a couple of times a year
  
• Apply fertiliser based on the results of these tests and the crop requirement
  
• Select grass and crop varieties that suit your farming system eg, in dry areas go for drought-resistant varieties
  
• Keep a good line of communication with the contractor carrying out the work