Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2004
Publication Date: 10/1/2004
Citation: Motavalli, P.P., Washburn, C.S., Lory, J.A., Kitchen, N.R. 2004. Use of apparent soil electrical conductivity to determine soil P distribution in poultry litter-amended landscapes [abstract] [CD-ROM]. ASA-CSSA-SSSA Annual Meeting Abstracts.
Technical Abstract: Sensors that measure apparent soil electrical conductivity (ECa) may offer a rapid, low-cost method to estimate spatial variation in soil P in poultry litter-amended pastures. The objectives of the research were: (i) to determine if spatial variation in ECa would relate to soil P distribution, and (ii) to compare the effectiveness of noncontract mobile electromagnetic induction (EM) and direct contact methods. Studies were conducted in Southwest Missouri on a long-term forage fertility plot site and three sites within beef cattle pasture fields, all having received long-term poultry litter applications. For the long-term plot site, both the direct contact ECa sensor deep reading and the EM-38 sensor in the shallow mode had significant positive correlations with soil test Bray-1 P at the 0 to 5 and 5 to 15 cm sampling depths. Significant spatial variation in soluble, soil test Bray-1 and total P were observed by landscape position within pasture fields. The EM-38 sensor in the deep mode had the highest significant positive correlations with soluble, soil test Bray 1 and total P for the pasture sites. These results suggest that soil ECa measurements may provide useful information for evaluating spatial variation in soil P due to manure applications. However, further research is needed to assess the processes and factors affecting this relationship and to develop calibrations between soil ECa and soil P.