​The low levels of sulphur we see today are not a new problem. Rather, it is something we've been aware of for over 30 years; ever since the first sulphur-deficient oilseed rape crops were seen on very light soils. Over time, this deficiency has progressed and now impacts virtually all crops and soil types. By looking at the factors that influence sulphur availability, you can make informed decisions and opt for products that match your crops' sulphur demand. 

With April quite literally around the corner and early nitrogen doses now applied, it's an opportune time to reflect on what's happened so far this season and factor in decisions for future applications. I believe it's always sensible to constantly question the fertiliser plans and programmes made earlier in the season and it's not to say they are wrong, it's to check they are still right!

It's one of the first questions we face from growers when discussing variable rate nitrogen (VRN) and it's understandable given sulphur is one of the major nutrients required by plants. If optimum amounts aren't available, it will have a direct impact on end yield.

As it happens, in nearly all of these conversations our recommendation to growers is to apply sulphur variably alongside their nitrogen in order to achieve optimum yields and quality. Of course, as with all nutritional decisions, some forward planning is required.

With this in mind, we're going to address some common questions to help you plan for the spring and ensure you get the maximum benefits from variably applying sulphur.

Well, it won't be surprising to learn that many soils will have lost nitrogen via leaching.

To demonstrate the impact, AHDB has produced a map to show the winter rainfall classification. This forms part of the RB209 book method for producing a Soil Nitrogen Supply (SNS) index and is a good starting point as you begin to look at your nitrogen programme for this spring. 

However, rather than rely solely on this information, our team at Frontier decided to carry out the measurement of Soil Mineral Nitrogen (kg N/ha) at a number of nationwide trial sites. The findings are outlined in the below table.