| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 85372 | Computers and Electronics in Agriculture | 2010 | 8 Pages |
High levels of subsoil salinity limit the growth and yield of dryland cereals in the Victorian southern Mallee, Australia. Currently available crop simulation models of wheat production perform poorly in this region, presumably due to their inability to account for subsoil limitations, mainly salinity. The objective of this work was to modify a spatially referenced Water and Nitrogen Management Model (WNMM) to account for the spatial pattern of subsoil salinity, by adjusting crop water uptake, in order to explain the spatial variation in wheat yield in this area. Measurements of above-ground biomass and yield of wheat, and the profile of soil salinity (0–80 cm) were made at 40 locations across an 88 ha paddock (35.78°S, 142.98°E) in the Victorian southern Mallee. The S-shaped water stress response function for crop water uptake proposed by van Genuchten (1987) was explored to modify the WNMM by adjusting the water uptake due to salinity, which significantly improved yield simulation over the original WNMM. The improvement in the model's ability to simulate wheat yield indicates that the subsoil salinity limits crop performance in the area. The incorporation of a salinity function in spatial crop models offers potential for simulating yield across a landscape and thus practicing precision agriculture provided salinity impact is considered dynamically.
Research highlights▶ The incorporation of a subsoil salinity function into a spatial crop model may help explain the variation in grain yield of a crop. ▶ In the arid and semi arid regions the effect of salinity on crop yield can be included by modifying the crop water uptake. ▶ The crop models must consider the effect of salinity dynamically at daily time step in order to accurately simulate crop yield.
