Map and Measure Soil Texture and Available Water

Electromagnetic (EM) sensors have been shown to be useful in mapping soil texture patterns and soil variability across even quite large farms – indicators that are intrinsically linked to crop yields, productivity in agricultural soils and farm sustainability. There is a defined relationship between soil conductivity (EC), soil texture and the soil’s ability to retain and deliver water to crops which can be readily used to map Plant Available Water Content (PAWC) and inform efficient water used through scheduled irrigation.

Queensland Drones provides precision electromagnetic (EM/ECa) soil zone mapping for even greater efficiency in farm and crop management. Using the state-of-the-art EM38 Mk2 ground-based electromagnetic profiler in combination with precision GPS location equipment, we can help you to identify and accurately map the key soil management zones for your farm, based on how well the soil will hold water, its salt content and how it will respond to fertilisers and other crop inputs. Accurate soil conductivity data, in conjunction with soil sampling and laboratory analysis, can help you to better manage fertilisers, irrigation and yield. We can also facilitate soil nutrient sample testing through a recognised NATA laboratory if required.

“When we started getting into yield mapping, it showed how soil type consistently impacted on yield and then how yield matched the soils’ water-holding capacity” – NSW grain grower Broughton Boydell (GRDC GroundCover magazine)

EM soil conductivity mapping is mainly about measuring sub-soil moisture holding capability, soil texture and salinity. Different soil types (sand, loam, clay, etc) will conduct electromagnetic energy differently, so using the right equipment it’s quite simple to map the different soil types, at different depths, across a field or an entire farm.

Soil conductivity is an excellent proxy for soil fertility, measuring how well the soil can retain water between rainfall or irrigation periods and how well the soil will absorb, retain and deliver key nutrients like nitrogen (K), potassium (P) and Magnesium (Mg) to the crop as it grows. EM soil conductivity mapping has been shown in numerous studies to be a reliably proxy for yield estimates in most soil types.

EM soil profiling allows you to limit expensive and complex soil testing to single sample points in each soil management zone, with sample point results able to be reliably interpolated to the entire management zone (zones of similar conductivity) and map soil variability across a field or an entire farm.

Our electromagnetic (EM) soil profiling data can help to determine:

  • Water retention capacity and drainage characteristics of each field – how soil zones absorb water and deal with excess water. Because water retention typically has the most significant major impact on crop yield, this alone should justify the investment in EC zone mapping.
  • Cation Exchange Capacity (CEC) of each field – how well the soil can absorb, retain and release essential crop nutrients like fertilisers.
  • Depth and profile of top soil for each field – identifying how deep the top soil goes before it reaches clay layers and rock outcrops.

Using this data, variable rate prescription maps can be developed to identify:

  • Variable seeding and nitrogen spreading rates based on CEC and yield targets
  • Variable tillage and seeding rates based on depth of top soil layer
  • Variable herbicide application rates based on CEC, soil texture and organic content
  • Variable lime application rates based on CEC levels and EC zones
  • Variable gypsum application rates based on soil sodic zones
  • No-till planting zones and seeding exclusion zones

Our EM soil conductivity mapping and soil testing services are guided by the best practice recommendations of Part 3 the GRDC’s Precision Agriculture Manual and conducted under the supervision of a highly qualified soil analysis scientist and GIS mapping consultant.

If you would like to find out more about EM soil profiling for your property, please complete the EM Soil Profiling Enquiry form or contact us now for an obligation-free chat.