The EM38 is an electromagnetic induction meter which measures and maps soil electrical conductivity requiring no instrument to soil contact. This is used to identify soil variability allowing the subdivision of fields into management zones based on the different soil types. The soil properties of the zones can be used to differentiate the application rates of seeds, fertilizers, irrigation water, optimizing input use and maximizing yields. The EM38 survey is a one off investment, soil types will remain constant in time.

 

WHAT IS AN ELECTROMAGNETIC (EM38) SURVEY?

EM surveying is carried out by towing the EM38 on a sled across the soil surface using a light-weight ATV, usually at a swath width of between 25m - 50m,. The EM38 readings are geo-referenced and logged at a rate of 1 per second. Our EM38 survey can provide comprehensive data on soil type characteristics at a rate of 400 ha per day.

 

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em38

 

WHAT YOU GET FROM IT

The EM38 survey will give you detailed maps of soil variability of topsoil, subsoil or both depending on the project. These maps will then be used to select targeted soil samples locations which our team will collect, analyze in our ISO 17025 accredited laboratory, and which will enable us to identify important soil fertility and water-holding properties. EM38 maps can be overlaid onto yield maps and used to sub-divide fields in different management zones and used to develop VR prescription maps for irrigation, fertilizer, lime spreading or seeding.

The example maps shown here demonstrate how the yield (top right) in this 100 ha pivot cultivated with rice is closely related to the soil conductivity recorded using our EM38 (top left). High soil conductivity and high yields are represented in blue, while low soil conductivity and low yields are in red. The bottom left map shows the available water holding capacity across the pivot, and bottom right the calculated management zones based overlaying yield and soil type.

SUMMARY

The EM layers are used to define management zones that can be used for differential application for optimizing inputs and maximizing yields. The more the data layers the more precise the management zone delineation (yield maps, EM38, topographic data).

The EM38 survey is a one off investment: the identified soil types are stable over time (unless major soil alterations are carried out). Soil sampling can be targeted per management zone for future soil sampling greatly reducing costs of this process as compared to grid sampling while increasing precision.

 

For more information or to get a quote for an EM survey, contact us