The power of mapping to assess nutrient management

I thought I'd take this opportunity to introduce myself to those who don't know me, I'm Richard Markham and I am a senior technical sales consultant for Frontier's precision farming business, SOYL. I have worked in the team for 19 years and support many farmers across the UK to gain a better understanding of their farms' performance, right down to what's going on in their soils.

Working with growers to better understand their baseline can aid future management decisions that deliver yield, quality and profit margins, but ultimately, measuring and monitoring soil health, nutrient status and overall field performance can support more informed decisions about how best to manage land in the most appropriate ways. This is particularly important during a time where farms are being encouraged more than ever to adopt a range of environmentally focused actions, while still maintaining sustainable food production systems.

In this blog, I'm going to be detailing the methods and research I've undertaken on my own farm to recover our soil. The findings have been truly interesting and have even led to some changes in approach for us. I hope you find the journey we've been on insightful and that it shows how you too can gain a better understanding of your own farm, as well as the potential improvements it could lead to.

How were my crops really using nutrients?

During harvest 2022, we saw the opportunity to undertake broad-spectrum grain analysis from the eight fields of winter wheat as I wanted to better understand my nutrient status and nitrogen use efficiency. The results (in the chart to the right) were not as I expected.

The soil phosphate analysis was taken at the standard depth of 15cm. On average, it showed an index of 2 / 2+ but the grain analysis on all eight fields showed phosphate to be critically low.

This gave me cause to review my historic sampling results in MYSOYL, comparing maps from the past three sets of analyses. These were taken (right to left) in the autumn months of 2015, 2019 and 2022. 

On-farm trials

In early March 2023, we carried out some variable rate nitrogen (VRN) trials on the second wheats. This involved taking some baseline deep nitrogen samples which gave the opportunity to take some P&K nutrient analysis at each depth (0-30cm/ 30-60cm/ 60-90cm) along with the available nitrogen.

This allowed us to form a map outlining a detailed nutrient profile on our farm, see images to the right.

The results, combined with the grain analysis results and historical sampling data to back this up, made me question: "What difference to yield (and quality) could I make by improving my nutrient status through the soil profile?" 

Plans for 2024 

After gathering these results, in autumn 2023 we decided to apply sewage sludge for the first time to provide a useful source of nitrogen, phosphorus and organic matter.

This autumn, we intend to implement some rotational cultivations on the farm after ten years of mainly shallow 'min-till' cultivations. Our reasons for doing this are:

• To loosen the soil after a season of record rainfall
• To mix the 0-15cms profile (high in nutrient status) into the 15-30cms profile (deficient)
• To bury the established weeds and reduce the effect of seed return.

We will also be using Sustainable Farming Incentive (SFI) actions alongside crop production, aiming to reduce this year's black-grass burden, lift the soils after the wet season and provide a more diverse rooting structure and depth. We will be putting in "AHL1: Pollen and nectar flower mix" in the form of a Kings Pollen and Nectar Mix.

This option also provides food for beneficial pollinators and encourages natural crop pest predators as part of an integrated pest management approach. We are hoping to see these benefits in our following winter wheat crop as we rotate the ALH1 each year, along with the fertility boost given by the clovers and vetch species in the mix.

The new precision farming action "PRF1: Variable rate application of nutrients" (available in SFI 2024) will also enable us to claim on our winter wheat area. We already use variable rate technology based on our 'per hectare sampling' to apply our TSP, MOP and lime, along with variable rate nitrogen which is based on our calibrated satellite imagery service.

Using the satellite imagery allows easy monitoring of Leaf Area Index (LAI) and crop development through the season. This results in more effective canopy management and ultimately makes the most efficient use of the nitrogen applied.

Future plans

Throughout the next three years, it'll be interesting to monitor the impact of a more diverse rotation including ALH1, along with the effect of mixing the nutrients through the soil profile. We'll look to see if there's an effect on the LAI and crop development in the following season's winter wheat crop, based on benchmarks through the growing season and in-field grain analysis taken at harvest.

For more information about the use of precision technology as part of the SFI, or if you'd like to learn more about our VRN service, you can contact at our team by emailing This email address is being protected from spambots. You need JavaScript enabled to view it. or calling 01635 204 190. More information is also available on the SOYL website. 

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