Crop sensing and variable rate application field talk

In February, LandWISE and the centre for precision agriculture at Massey, hosted a talk by Jim Wilson of Soil essentials in Scotland at Hew Dalrymple ‘s property in Bulls.  Jim was here as a speaker at the FLRC workshop. He runs a farm in Scotland and works with farmers to bring GPS, sensing and data management onto their farms. He presents simple ways to bring technology into creating certain savings on fertiliser, fuel and steel, on the farm.

Sensing the ‘greenness’ of a crop canopy, combined with sound agronomy, can be a great tool for managing nitrogen application. The key to this technique, is the efficiency with which the soil can deliver the nitrogen to a given plant or part of the crop.

A variable rate nitrogen system can be designed once any other limiting factors, such as pH and water have been eliminated. This technology has been adopted strongly in the UK because of caps on N fertilizer levels, which mean that farmers are driven to apply correct levels depending on site variability and plant needs.

To view Jim’s soil essentials website see:

At the same session, Carolyn Hedley of Landcare, presented on recent work with EM38 sensing which is being used to schedule variable rate irrigation. This is done by determining water holding capacities of soils using a combination of sensing and soils knowledge, then programming the output of centre pivot irrigation, nozzle by nozzle, according to these results.

More information about variable rate irrigation is available at:

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