Submitted to: Proceedings Great Plains Soil Fertility Conference
Publication Type: Proceedings
Publication Acceptance Date: 3/3/2006
Publication Date: 3/15/2006
Citation: Wienhold, B.J., Koerner, P.T. 2006. Apparent electrical conductivity as a tool for delineating spatial patterns in inherent soil properties. Proceedings Great Plains Soil Fertility Conference 11:161-165. Interpretive Summary: Crop yield varies within a field and part of this variability is due to differences in soil properties within the field. Economically mapping variation in soil properties and understanding how this variation effects crop yields will allow farmers to vary management to improve efficiency and reduce negative environmental impacts. An electromagnetic sensor was used to map variation in soil properties. A statistical program was used to process the data and select soil sampling sites. Soil properties measured at these sites and patterns in soil variability measured with the sensor were used to estimate variation in these soil properties for the whole field. This approach is more efficient than other soil sampling methods and when combined with yield maps, aerial photography, and weather information has potential for improving management of variable fields.
Technical Abstract: Soil properties affecting crop yield exhibit spatial variability. Apparent electrical conductivity (ECa) can be economically measured and is well correlated with many soil properties. Methods for processing ECa survey data and determining the relationship between ECa and soil properties are needed. An ECa survey was conducted on two fields and processed using the ESAP computer program. Soil samples to calibrate and validate the program were collected. An initial assessment resulted in a successful calibration for soil water content, bulk density, total dissolved solids, pH, Bray available P, soil organic matter, and clay content. Validation was significant for only total dissolved solids, organic matter, and clay content. Validation of additional soil properties may result with more thorough analysis of the data or an increase in the number of soil samples. Based on this initial assessment we conclude that the ESAP program has potential for processing ECa survey data, determining soil sampling designs, and relating measured soil properties to ECa.