The strategy regarding phosphate management has been untouched for decades – ‘feed the soil to feed the crop’. But as growers look for ways to increase efficiency, Yara asks whether we should be reconsidering our approach to phosphate management.
Dr Roger Sylvester-Bradley, head of crop performance at ADAS, highlights the current model used to determine applications has remained rigid for a long while. “Philosophies can change,” he says. “The current philosophy of P management – ‘feed the soil to feed the crop’ – was introduced in the 1960s in England and Wales. Recent evidence from AHDB-funded research shows this guidance is, for most crops, generous.
There is merit in admitting that, while current recommendations are ‘safe’ in terms of avoiding crop deficiencies, they are grossly inefficient and will be unsustainable in the long-term.”
After years of uniform guidance, many farms are rethinking their nutrient strategies by making small adjustments for better efficiency and yield.
“There are significant uncertainties in managing P,” adds Dr Sylvester-Bradley. “We suggest regular monitoring over and above the soil analysis every four years to ensure the crop is not becoming deficient.”
Natalie Wood, country agronomist at Yara UK, explains a key area to consider when re-evaluating applications is the uptake of phosphate from the soil.
“Our research shows as much as 90% of applied phosphate does not reach the crop. Targeted applications, based on farm evidence and carefully managed crop nutrient plans are the way forward if farms are considering minimising inputs to maximise returns.”
Mark Tucker, head of agronomy at Yara UK and crop nutrition seminar chair, believes all farms could see the benefit in reconsidering their P management strategy.
“It is in everyone’s interests, from sustainable resource management, right through to farms. We can – and should – start to change P management practices to improve profitability without jeopardising long-term fertility of the soil or quality of the crop.”
Yara will be sponsoring the crop nutrition seminar stream at CropTec Show 2017.
The company will be focusing on key messages for effective crop nutrition, and how best to use data for efficient long-term soil management.
Yara’s digital platform, MyYara, facilitates this by offering leading precision farming tools, enabling farmers to manage and optimise the yield of their crops.
Agronomy manager for Yara Mark Tucker says: “MyYara puts the farmer in control. Personalised analysis helps ensure growers get the most from their field and crop. This is an exciting time to register; we are always developing further analytic tools to give farmers the edge, with even greater functionality coming soon.”
For a limited time, growers which register for MyYara will get a free soil or tissue test and will be entered into a draw to receive YaraVita products.
Ian Matts, arable director at Brixworth Farming in Northampton, is keen to investigate the standard recommendations for phosphate use, and whether they might be adjusted for individual farms. Through targeted experimentation and careful planning, he investigated whether a ‘one size fits all’ index is really the best approach, or whether it is possible to boost efficiency without compromising yield. In doing so, he has transitioned the whole farm from the middle of index 2 to the top of index 1.
“For years we went down the path of precision inputs to try and even up our indices, and found that we were seeing an improvement in the colours on the maps,” says Mr Matts. “What strikes me is this is called ‘precision agriculture’ but there is nothing precise about using index 2 everywhere. The research, although substantial, is based on a limited range of soil types and assumes all crops are equal.”
Mr Matts points out that with detailed advice available to farmers on nitrogen use for different soil types – and for different indices – it is counterintuitive for phosphate use to be universal across different farms and soils. “One value for everything doesn’t necessarily result in the best yield.”
Mr Matts originally based his application on a flat index across the board, but gently scaled it back from index 2, and supplied fresh phosphate to the crop across the year. In addition to biannual applications of Triplesuperphosphate, he also uses sewage sludge as part of the nutrition programme. So far, he has been able to use less phosphate while achieving the same yield, increasing efficiency without sacrificing quality.
Despite the encouraging results, Mr Matts strongly advises caution and investigation before reducing from index 2.
He says: “If people are interested they need to work out what will work for them, rather than relying on a table which covers all of England and Wales and all the soil types in it. Looking closely at what works for your farm, your situation, your soil, means you can make small adjustments to find the best process for a better crop.”