We construct a stochastic dual model to investigate the structural adjustment of three aggregate input and two aggregate output categories in U.S. agriculture under climatic change uncertainty. A century of national annual data (1910-2011) is used in the empirical analysis. Independent and instantaneous adjustment is rejected for each output and input, but strict fixity cannot be rejected for livestock and capital. It takes about four years for crops, and three years for fertilizer to adjust towards their optimal levels. Labor adjustment reaches the equilibrium within one year.