Electromagnetic mapping of your farm could help you improve productivity. Here are four things you need to know.
1.Electromagnetic (EM) maps measure variations in soil texture which affects the amount of plant available water the soil can hold. They work by indicating the variations in the ability of the soil to conduct electricity. This in turn determines the type of soil texture.
2.EM maps help to explain yield differences by differentiating wetter, finer textured zones from drier coarser textured zones. These maps can be used for zone management to reduce inputs in low yielding zones or to improve yields in better yielding zones.
3. The ability of soil to conduct electricity depends on factors such as soil texture salinity and moisture. Clay soils have a very high EM value because they conduct electricity better than dry stony soils.

4. EM maps can be used to develop water available holding capacity maps indicating the different water holding capacity in soils in any given area. The information can be used in variable rate irrigation to maximise the effectiveness of irrigation. For more information contact Landcare Research Ph 03 321 9999.

 Copyright © The Main Report Group - NZ AGri-Business