Testing the feasibility of quantifying change in agricultural soil carbon stocks through empirical sampling - ScienceDirect

Fig. 1. Box plots of relationship between within-field sampling densities and the accuracy of soil organic carbon (SOC) inventory estimates for each of 100 sampling iterations. Shown are estimates for three fields (F1-F3), with the working truth inventory estimate shown as the central horizontal solid line in each plate, with the sampling density increasing from left to right on the x-axes. Fields are ordered from left-to-right (i.e., a-c) by decreasing within-field variability (CVs) and y-axes differ in scale given different stock estimates of each field. Horizontal dashed lines show deviations of ± 3 Mg C ha−1 from the true value. Box plots show the median stock estimate across the 100 runs as the thick, center line in each box. The top and bottom of the box bound where half of the inventory estimates fall, with one quarter of the inventory estimates falling below the median line in the box, and one quarter above the median line. The vertical lines then are meant to stop at the top a

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