Click on image to view larger version.
Fig. 1. (A) Soil particulate organic C (POC) content and (B) POC/soil organic C (SOC) ratio at the 0- to 5-cm depth, averaged across tillage, as influenced by crop rotation. Crop rotation is CW, continuous spring wheat (Triticum aestivum L.); W-F, spring wheat-fallow; W-L, spring wheat-lentil (Lens culinaris Medic.); W-P-F, spring wheat-pea (Pisum sativum L.)-fallow; and W-W-F, spring wheat-spring wheat-fallow. Bars followed by the same letter at the top are not significantly different at P 
0.05 by the least square means test. Values for conservation reserve program (CRP) are shown for comparison only and not used in the statistical analysis of data.
