A two-stage approach is used to estimate sensitivity of corn, wheat, and soybean yields to changes in prices and land idled. Estimated elasticity of demand for fertilizer per acre with respect to expected output price equals 0.47, 0.10, and 0.82 for corn, wheat, and soybeans. Upper estimates of the elasticity of yield with respect to fertilizer equals +0.58, +0.29, and +0.16 for corn, wheat, and soybeans. Yields are found to be quite insensitive to price changes. Fertilizer demands and yields are insensitive to land idled under farm programs
