MAPPING AND INTERPRETING THE YIELD VARIATION IN CEREAL CROPS

The existence of spatial variability within fields points to considera ble benefits if inputs to arable crop production are targeted accordin g to locally determined requirement. The paper discusses yield mapping as a data source on variability and emphasises the need to integrate data on all sources of spatial variability with the management/agronom ic expertise of the farmer to develop an application strategy for fiel d inputs. A yield mapping system is described and examples of yield ma ps from one field in four successive years, together with data on soil spatial variability are presented. An exploratory study was made of a ppropriate statistical techniques to compare yield maps analytically. Consistency of yield variation in the test field from season to season and correlation with a limited sampling of soil nutrient parameters w ere low. However, significant correlation between soil series and yiel d was observed.