Geo-referenced information on crop production that is both spatially- and temporally-dense would be useful for management
in precision agriculture (PA). Crop yield monitors provide spatially but not temporally dense information. Crop growth simulation
modelling can provide temporal density, but traditionally fail on the spatial issue. The research described was motivated
by the challenge of satisfying both the spatial and temporal data needs of PA. The methods presented depart from current crop
modelling within PA by introducing meta-modelling in combination with inverse modelling to estimate site-specific soil properties.
The soil properties are used to predict spatially- and temporally-dense crop yields. An inverse meta-model was derived from
the agricultural production simulator (APSIM) using neural networks to estimate soil available water capacity (AWC) from available
yield data. Maps of AWC with a resolution of 10 m were produced across a dryland grain farm in Australia. For certain years
and fields, the estimates were useful for yield prediction with APSIM and multiple regression, whereas for others the results
were disappointing. The estimates contain ‘implicit information’ about climate interactions with soil, crop and landscape
that needs to be identified. Improvement of the meta-model with more AWC scenarios, more years of yield data, inclusion of
additional variables and accounting for uncertainty are discussed. We concluded that it is worthwhile to pursue this approach
as an efficient way of extracting soil physical information that exists within crop yield maps to create spatially- and temporally-dense
datasets.
Keywords Inverse modelling – Soil available water capacity – Meta-modelling – Precision agriculture – Crop growth simulation modelling