Gearing up for variable rate on winter wheat

16 March, 2019

Spring is here and your work on the fields is in full flow. Fertiliser applications and pest control will be top of your agendas. Applications tend to be generic across farms and fields, but have you ever considered whether your soils are consistent across your farm? Most farmers are aware that their fields vary with soil type, aspect and just basic growing potential. It is often difficult, however, to quantify these differences. How much more or less nitrogen should you be applying?

Fortunately, technology is once again at hand to help. There are numerous ways now to manage your soil and field variability in such a way that you can optimise your inputs, raise yields and therefore, increase your margins.

So how do you go about this?

You can start at either end of the harvest year. At the beginning, you can scan your fields with an electromagnetic scanner, which effectively measures the soil characteristics from which an assessment of soil property variability can be made.

Fig 1. Soil conductivity mapping showing soil property variability across multiple fields

Or you can start at the end by taking your yield data as a guide to variability as the yield will vary with the soil potential or limiting factors to growth. Understanding limitations are key.

Fig 2. Yield mapping as basis for field variability

There are other methodologies which include direct soil sampling and the use of sensors to determine the nitrogen content of a crop which enables you to apply nitrogen variably such that the plants are getting the right level of nutrient.

These methodologies can also be used for seeding rates such that you seed the density more in accordance with the potential of the soil in terms of yield.

If you would like to know more about variable rate applications, contact us at