Precision placement increases crop phosphorus uptake under variable rainfall: Simulation studies

The objective of this paper was to evaluate soil and climatic factors affecting crop P uptake and yield when P was placed at different soil depths using APSIM. Nutrient stratification, particularly soil immobile nutrients such as phosphorus (P), could have a significant impact on availability of nutrients to crops, as soil immobile nutrient availability, root growth and root activity in the surface layer are more vulnerable to drought than those in sub-surface layers. Placing P fertiliser deeper in the soil was demonstrated in the early field studies to improve crop P uptake and yield in a water-limited environment of Western Australia (Jarvis and Bolland 1990). However, soil and climatic factors (and their interactions) driving the benefits of deep P fertiliser placement are not well understood.