Cereals: The Arable Event

Yara’s big data set – lessons for 2017

01-Feb-2017 Yara

Nitrogen is undoubtedly the number one nutrient in the search for higher yields.

However, the need to identify other limiting factors that might prevent a crop from realising its full potential is a key lesson to be learnt from Yara’s Big Dataset, believes Jon Telfer, Development Manager at Yara Analytical Services.

Furthermore, the earlier these limiting factors can be discovered  and, where possible, addressed, the better the outcome in terms of yield and productivity.

“We have been performing analysis of soil, tissue and organic manures for over 40 years in our lab in Pocklington and collecting data electronically since 1995,” says Mr Telfer.   “This has given us over 20 million data points, and growing, from which to learn and provide insight for farmers. Our dataset from 2010 to 2016 certainly shows that limiting factors are widespread, but variable, making soil testing and analysis on individual farms essential.”

What are limiting factors?

Limiting factors can range from soil conditions, soil fertility, disease and weed pressure to a shortage of other key crop nutrients.

Soil fertility is key and, rather than guessing, factors such as soil type and texture and biological fertility should be measured, including organic matter (OM) analysis.

Chemical fertility – and identifying gaps in a soil’s status and performance - is where soil analysis really comes into its own, maintains Mr Telfer. “It provides an opportunity for the individual farmer to identify the factors on his or her own farm that are going to hold back yield. Crops need a variety of nutrients to complete the growing process – macro and micro nutrients - and a deficiency of any single one is enough to limit yield.”

Lessons from the data set

So, with this in mind, what does Yara’s data set, using figures from 2010-2016, tell us about potential limiting factors?

The first thing to check is soil pH. “We know that having the right soil pH, between 6.5 and 7.5, is vital for utilising the nutrients that exist within our soils. However, our data for UK arable soils shows that of the 500,000 soils processed almost half needed some form of pH management, with 20% having a pH of less than 6 liable to impact on NPK usage efficiency.  Making sure your pH is right must be the starting point.”

  Big Data findings: identifying the limiting factors
  • Almost half of UK arable soils are below pH 6.5
  • Soil deficiencies of P&K are widespread but variable:
    • 1 in 4 UK arable soils are P deficient
    • 1 in 3 UK arable soils are K deficient
  • Soil sulphur levels are exhausted
  • Half of samples were deficient in 2 or more key nutrients 

P&K deficiency

Low levels of crop available phosphorous and potassium are also known to limit yields and also limits the effectiveness of N applications.  

“Again, our data shows that a quarter of arable soils tested in the UK are at potentially yield inhibiting levels of phosphorous deficiency,” says Mr Telfer, with over half of UK soils needing phosphorus management, that is building up or replacing what we are removing after offtake by crops.  Similarly, a third of soils have potentially yield inhibiting (index 0 or 1) levels of potassium with over half requiring potassium management.”

Identifying the limiting factor – Nutrient supply - Phosphorus

Nutrient supply - phosporus


Identifying the limiting factor – Nutrient supply - Potassium

Nutrient supply - Potassium

Sulphur Reserves Exhausted

In 1995, 63% of soils analysed were below Yara guidelines for plant available sulphur.That figure is now 96-7%, says Mr Telfer, we can safely say that reserves of sulphur are exhausted, hence why it is now considered a major nutrient alongside NP&K.”  

Range of nutrients

Whilst NPK and sulphur are the major nutrients, plants require a whole range of nutrients for different functions and a deficiency in any of them is enough to limit yield. 

“Again, looking at our big data only 13.5% of UK soils had adequate pH and nutrients (including manganese, copper and zinc) for a healthy winter wheat crop. This means that if you invest in soil analysis, 7 times out of 8 you will identify potential opportunities to improve yield and productivity.  The same was true for oilseed rape soil: by including manganese, boron and calcium, only 7% of soils were found ‘fit for purpose’.”

Book value or test?

Another area in which the big data set offers insight is the value of organic inputs. Just how accurate are the given book values?

Analysis shows that whilst accurate measurements of nitrogen and phosphate are variable, they do hover around the book value in RB209.

Slurry K2O kg/m3 by Season

But potassium measurements going back to 2005 never matched the value stated in RB209. So if we rely on these book values to populate our nutrient management plans we could be building in inaccuracies.  It is better to test and use accurate figures.

Leaf testing – early identification

Leaf testing is the most effective way of monitoring actual nutrient uptake,” says Mr Telfer.  ”It gives you the opportunity to identify deficiencies before they become chronic and show themselves as visible symptoms.  In fact, over half of the winter wheat tissue samples processed through the lab between January and June 2016 were deficient not just in one but multiple micronutrients.”

  • 86.7% of samples were deficient in at least one key micronutrient: Zinc, Copper or Manganese
  • 57.3% had 2 or more key micronutrient deficiencies

Opportunities to benefit

Yara’s big data set confirms that, as suspected, UK arable farmers are confronted by a wide range of potential limiting factors, but this also presents many opportunities. 

Farmers can identify and correct limiting factors before they start nutrient programmes, suggests Mr Telfer: “Testing early gives the opportunity to correct any deficiencies, or combination of deficiencies, through the tank before the plant has reached a point of stress from which there is often no return.

“As an example, our data on PK and S deficiency confirms that many farmers will certainly find their need for straight N is far less than they thought, opting for NPKS and NS instead - to their advantage. 

“In cereal crop trials the use of NS has led to yield increases of 0.3 t/ha, whilst in oilseed this has been higher at 0.5 t/ha,” says Mr Telfer, “and using a granulated nitrate plus sulphate product will result in an ROI of between £2 and £10 return for every £1 invested.”

“Similarly switching a first spring application to a ‘Spring Starter’ - NPKS Complex Compound Fertilizer (CCF) will give arable crops the best possible start in the spring as they look to recover root and shoot growth lost over the winter.  Research into this approach have shown a consistent yield increase of a further 0.25 – 0.3 t/ha, above the expected sulphur response.”


Notes to Editors:

Yara UK Limited is the UK & Ireland operating business unit of Yara International ASA, headquartered at Grimsby in NE Lincolnshire. www.yara.co.uk

Yara UK Ltd – the only company to market and distribute the complete range of plant nutrition products for agricultural, horticultural and amenity and protected (greenhouse) crops for farmers and growers. Our fertilizers all supported by a FACTS qualified regionally based team of advisors and a number of precision tools and apps.

Our product combinations include:

Established and trusted Yara branded bagged solid nitrate based brands

UK manufactured Yara range of Chafer liquid clear solution liquid fertilizers

YaraVita trace element and micro-nutrient seed treatment and foliar products formulated to be tank mixed. Check suitability at www.tankmix.com

Yara International ASA is a leading chemical company that converts energy and nitrogen from the air into essential products for farmers and industrial customers. As the number one global supplier of mineral fertilizers and agronomic solutions, we help provide food for a growing population.

Yara International ASA has 10,000 employees worldwide, operating in 120 countries with facilities in more than 50 and with a turnover in excess of £6.5 billion. The head office of Yara International is in Oslo, Norway.



Event Partners