New trial results announced at the Livestock Event show Sulphur delivered a 29% increase in grass growth for first cut with swards remaining responsive to further applications as the season progresses.
“Like 2015, 2016 is turning out to be a very Sulphur responsive year but we’re seeing significant responses to Phosphorus, too,” says independent grassland specialist Dr. George Fisher.
“The overriding message for farmers is to consider using a Sulphur-containing fertiliser this year and don’t cut back on maintenance applications of Phosphorus.”
The trials, which took place in Cheshire and Devon, were commissioned by CF Fertilisers as part of their commitment to independent and replicated grassland research.
The work follows trials from 2014/15 in which useful responses in grass yield to Sulphur, even on heavier soils, and to maintenance applications of Phosphorus on P index 2 and 3 soils, were seen.
In the latest trials on medium loam soils in Cheshire, a 100kg/ha application of straight N (Nitram) delivered a yield of 4.55t DM/ha for first cut silage whilst the addition of 44 kg/ha of Sulphate (as SingleTop) lifted this to 5.85t DM/ha– a 29% increase.
These applications also produced an extra 0.8t DM/ha for early grazing.
On a heavier clay loam at the Devon trials site, response to Sulphur was 10% for the same levels of application as the Cheshire site, whilst when Sulphur and Phosphorus were added together, yields increased from 4.2t DM/ha from the straight Nitrogen to 5.2t DM/ha – an impressive 24% lift.
At a time when getting the most out of home-grown feed has never been more important, the results are highly significant, George Fisher believes.
“If you assume a 75% utilisation rate from field to feeding, this extra 1t/ha DM for first cut silage at 11 MJ ME contains enough energy to produce 1,530 litres of milk or 175kg of liveweight gain. Well worth having.
“Similarly, an extra 0.5t/ha DM for early grazing at 12 MJ ME and an 85% utilisation rate, produces enough energy to produce an 845 litres of milk or 110 kg liveweight.”
The responses to Phosphorus are also very interesting with an application of 40kg P2O5 (water soluble phosphate) giving up to 17% more grass DM yield on first cut silage and 8% on the first two grazings, he points out.
“These responses are occurring when soil P indexes are already at 2 and 3, suggesting that maintenance applications of P in this form are used efficiently and provide a highly beneficial yield response.
“All in all, it shows that livestock producers need to think much more about their land’s nutritional needs if they want to produce the highest cost-effective yields of forage.
“Doing so is certainly advantageous, with the cost/benefit in milk production showing a £20 return for every £1 spent on Sulphur and up to £12 for every £1 on Phosphorus.”
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