Yield Maps of Grain and Straw in Japanese Paddy Field

Abstract

Using mapping techniques, spatial variability of yields in grain and straw for rice plant was investigated over a 0.5ha paddy field on the Experimental Farm, Kyoto University, Japan. Test plant was Oryza sativa L., cv. MINAMI-HIKARI, a high-yield variety. Grid sampling was conducted with three rectangular spacings: 1.2m width and 1m length, 6m width and 5m length, and 12m width and 10m length, in order to take account of the grid size effects. In 1.2m×1m grid spacing yield variations resulted in 5.5 to 9.7t/ha for grain dry mass and 6.2 to 18.0t/ha for straw dry mass. Experimental semivariograms revealed the spatial dependency of yields with respect to grain and straw.