02522naa a2200229 a 450000100080000000500110000800800410001902400420006010000160010224501510011826000090026950000920027852017570037065000210212765000100214870000150215870000170217370000160219070000190220670000150222577300520224010329662021-06-28       2004    bl uuuu     u00u1 u    #d7 a10.1097/00010694-200412000-000012DOI1 aTERRA, J.A.  aSoil Carbon relationships with terrain attributes, electrical conductivity, and a soil survey in a coastal plain landscape.h[electronic resource]  c2004  aArticle history: Received May 3, 2004 // Accepted Sept. 30, 2004, Publishing Dec. 2004.  aSoil organic carbon (SOC) estimation at the landscape level is critical for assessing impacts of management practices on C sequestration and soil quality. We determined relationships between SOC, terrain attributes, field scale soil electrical conductivity (EC), soil texture and soil survey map units in a 9 ha coastal plain field (Aquic and Typic Paleudults) historically managed by conventional means. The site was composite sampled for SOC (0-30 cm) within 18.3 × 8.5-m grids (n = 496), and two data sets were created from the original data. Ordinary kriging, co-kriging, regression kriging and multiple regression were used to develop SOC surfaces that were validated with an independent data set (n = 24) using the mean square error (MSE). The SOC was relatively low (26.13 Mg ha?1) and only moderately variable (CV = 21%), and showed high spatial dependence. Interpolation techniques produced similar SOC maps but the best predictor was ordinary kriging (MSE = 9.11 Mg2 ha?2) while regression was the worst (MSE = 20.65 Mg2 ha?2). Factor analysis indicated that the first three factors explained 57% of field variability; compound topographic index (CTI), slope, EC and soil textural fractions dominated these components. Elevation, slope, CTI, silt content and EC explained up to 50% of the SOC variability (P ? 0.01) suggesting that topography and historical erosion played a significant role in SOC distribution. Field subdivision into soil map units or k-mean clusters similarly decreased SOC variance (about 30%). The study suggests that terrain attributes and EC surveys can be used to differentiate zones of variable SOC content, which may be used as bench marks to evaluate field-level impact of management practices on C sequestration.  aMANEJO DEL SUELO  aSUELO1 aSHAW, N.J.1 aREEVES, D.W.1 aRAPER, R.L.1 aVAN SANTEN, E.1 aMASK, P.L.  tSoil Science, 2004, V. 169, No. 12, p. 819-831.