Fig. 4. Mean gravimetric moisture content, respiration, and CO₂ efflux of the rototilled, disked, and control soils in the ancillary experiment. (a) Gravimetric moisture, (b) respiration, and (c) CO₂ efflux. The soils were irrigated at 0 h. The error bars are the standard error of the mean (n = 3). Different letters indicate significant differences (P < 0.05) using t tests between treatments at each time. No t tests were done for the moisture data since only one replicate per treatment combination was analyzed.