Agricultural prices are determined by natural and socio-economic factors that are known to be self-similar at different time scales and to follow non-periodic cyclical patterns. These properties are most easily understood using Mandelbrot's fractal geometry, in which a jagged time series is treated as a jagged coastline or any other natural phenomenon. The fractal market hypothesis provides the theory needed to explain why fractal structure exists in agricultural prices. Empirical evidence confirms theoretical predictions.