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ARS Home » Midwest Area » Columbia, Missouri » Cropping Systems and Water Quality Research » Research » Publications at this Location » Publication #134884


item Sudduth, Kenneth - Ken
item Kitchen, Newell
item Drummond, Scott

Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Other
Publication Acceptance Date: 7/31/2002
Publication Date: 7/31/2002
Citation: Sudduth, K.A., Kitchen, N.R., Drummond, S.T., Bollero, G.A., Bullock, D.G., Chung, S. 2002. Soil strength sensing for quantifying within-field variability. American Society of Agricultural Engineers. Paper No. 021182. CDROM.

Interpretive Summary: Precision agriculture is a crop management strategy which seeks to address within-field variability. An important aspect of within-field variability is soil physical condition. The cone penetrometer is an automated device that measures the force required to penetrate the soil as an indicator of the level of soil compaction. Excess soil compaction impedes plant root growth, so it is desirable to locate and manage compacted areas within fields. In this research we collected penetrometer data in producer fields in Missouri and Illinois and related the data to laboratory-measured soil characteristics, topography measurements, and soil electrical conductivity (EC) measured with on-the-go sensors. We found that penetrometer force measurements were strongly related to soil water content, soil texture, and measurement depth for both sites. We also found that penetrometer force was related to soil EC but not to topography. This research will benefit other researchers by documenting the relationship between penetrometer data and soil physical properties for specific soil types. It will also benefit researchers and practitioners by documenting the relationship between soil strength and EC on claypan soils. It may be possible to use this relationship to interpolate between widely spaced penetrometer measurements and create more complete representations of soil strength over entire claypan soil fields.

Technical Abstract: Within-field variations in soil strength can significantly affect crop growth and yield by changing the hydrologic characteristics of the soil and its suitability as a medium for root growth. The purpose of this study was to relate soil strength, as measured with a cone penetrometer, to soil and landscape characteristics on fields in Illinois and Missouri. Penetrometer cone index (CI) measurements were obtained at sampling points where detailed soil profile analyses, along with soil electrical conductivity (EC) and topography measurements, were also available. CI and profile soil properties were generally more variable within the Missouri field than in the Illinois field. Near the soil surface, within-field CI variations were correlated only to depth. At deeper depths, CI variability was related to soil texture and soil water content as well as depth. For the Illinois field, CI variability was also related to inorganic carbon, due to the presence of calcium carbonates at depth. In this study, CI was not correlated to bulk density. CI was not correlated to topography but was correlated to soil EC measurements, with the strongest relationships being found on the Missouri field. For the Missouri field, maximum CI and the depth to the maximum CI were both linearly related (r^2 = 0.22 to 0.67) to soil EC.