Rising incomes in key markets and a depressed dollar helped push U.S. containerized exports in August up 5.4 percent year-over-year, marking a three-month high, reportedThe Journal of Commerce/PIERSthis week. Overall containerized exports rose 1.2 percent over July volumes and 8 percent year to date, through August.

Measured in 20-foot equivalent units, the exports totaled 977,330 TEUs for a second consecutive monthly gain. Volumes were led by an impressive 119 percent jump in soybean shipments and 32 percent boost in scrap metals.

"The notable jump in soybeans is likely tied to declining container freight rates, which has prompted many U.S. agricultural exporters to switch from bulk to container transportation," saidMario O. Moreno, economist for The Journal of Commerce/PIERS. On the low end, he noted that severe drought inWest Texashas caused fabrics including raw cotton to continue its downward trend, losing 52 percent of its outbound volume.

Total U.S. exports in July and August were up 5.2 percent over the same period last year, in line with a previous forecast of 6.3 percent gains in the third quarter. Moreno predicts 2011 will close with total containerized exports up 6 percent from 2010.