Soybeans declined on Tuesday falling from the strongest level in a two-month period as traders weighed speculations that crops in Brazil and Argentina may be boosted by local rains against signs that demand for U.S. supplies rises. January soybeans futures slid 0.4% to $13.24 a bushel on the CBOT and traded at $13.2475 as of 2:19 p.m. Singapore time.