While grass has long been recognised by dairy farmers as the most economical source of feed, few consider its nutritional value when buying their fertiliser to grow it.
The British Survey of Fertiliser Practice 2019 shows that 40% of the 1.2 million tonnes of fertiliser applied to grass each year is straight nitrogen. Is this a missed opportunity in terms of balancednutrition to optimise not only grass yield but, arguably more importantly, forage quality?
Origin’s Nutrition Agronomist Hannah Peile explains:“When a dairy farmer chooses which compound feed to buy, the decision is based on energy, protein and raw material inclusion depending on the requirement of the cow.
“At Origin Fertilisers, we consider that feeding grass is no different. The nutritional requirement of the grass should be considered, and the fertiliser applied should match that requirement.”
Origin Fertilisers put this hypothesis to the test in an independent research trial conducted by the National University of Ireland in 2019 which compared a ‘standard’ analysis complex compound – 24.6.12 – against an Origin NUTRI-MATCH ‘prescription’ fertiliser.
Both products supplied the same amounts of N, P and K. However, the broad-spectrum soil analysis highlighted deficiencies in sulphur, sodium and selenium which could potentially affect forage quality. Sulphur, sodium and selenium were therefore added to the prescription fertiliser to correct the deficiencies identified in the soil analysis.
Sulphur is essential in optimising dry matter (DM) production and formation of true proteins. RB209 Prescription Fertiliser Improves Soil Fertility, Yield and Crop Quality notes a critical sulphur level in grass of > 0.25% and a nitrogen to sulphur ratio of 12:1 or lower.
Sodium is essential in optimising sugar content which improves palatability and therefore dry matter intakes. In conserved grass, sugars convert to acids which aid fermentation and preservation. Sodium also plays a key role in optimising mineral balances and reducing the risk of hypomagnesemia (grass staggers).
Selenium levels were low, in line with 90% of UK soils. Selenium is essential for animal health and applying it through the fertiliser elevates the levels in pasture and forage towards optimum or required levels.
While the DM yield was very similar between the fertiliser treatments, the nutritional value of the grass treated with the NUTRI-MATCH prescription fertiliser was greatly improved.
Compared to the ‘standard’ compound, the NUTRI-MATCH prescription compound:
- Produced an additional 0.15 tonnes per ha of DM worth £22.50 per ha
- Increased digestibility (D-value) and energy (ME)
- Increased the sodium content by 59% which helped increase sugars by 21% and reduce the potassium to sodium ratio by one-third which reduces the risk of staggers
- Increased the sulphur content by 25% which improved the nitrogen to sulphur ratio from marginal to optimal – this will have increased the formation of amino acids
- Increased the selenium content by 178%
“Applying a prescription fertiliser based on matching soil and crop nutrient requirements can improve soil fertility, yield and crop quality,” concludes Mrs Peile. “Targeted nutrient inputs can save you money and help protect the environment.”
Since the introduction in England two years ago of mandatory soil sampling under the Water Framework Directive, accurate field data is enabling
farmers to match soil and crop requirements with prescription fertilisers to optimise the nutritional quality of grass.
The Professional Agricultural Analysis Group 2018/19 data shows that prescription nutrition is needed now. Covering over 125,000 UK grassland samples, 19% still show a soil pH of less than 5.5 and only 26% were at the target potassium index of 2-, and 30% at target phosphate index 2. Overall, less than 10% of all samples were at target index for both P and K, highlighting a real opportunity for improved nutrition.
A Carrs Billington full soil health check is essential for building a nutrient management plan that meets legislative requirements, as well as examining a further 8 nutrients including selenium and sodium, essential for healthy, profitable cows.
Carrs Billington advisors recommend NUTRI- MATCH blended fertilisers, made from a choice of up to 14 essential nutrients to address every part of the deficiency or excesses identified in the full soil analysis.
Reducing nutrient excess can have a positive environmental impact, and the flexibility that a fertiliser blender has to use different raw materials to produce a grade can reduce its carbon footprint. Origin’s raw materials are all tested under European Standard EN 1235/A1, meaning that there is no compromise in product quality.
Ask your Carrs Billington specialist about NUTRI-MATCH prescription fertilisers and see real benefits in the quality of your grass and your dairy herd.
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