Since the image is in Chinese, I believe that I keep it to its originality because I'm afraid that editing it will mess up with the intricate pictorial details that are currently present. Instead, I will provide a detailed explanation to the different legends in here:

Both legend scales(the horizontal line strip and the Piesces symbol) on the top role indicate the Rice Paddy Distribution

Both scales on the middle row (the vertical line and the t symbol) indicate Wheat Distribution

Both Scales on the bottom row (the row of light dots and the single bold, solid dot) indicate corn, millet, sorghum and other possible crops in China)