Fertiliser decision support systems need to be reassessed as cropping systems change. Our analysis of a series of 40 field experiments showed that phosphorus buffering in the topsoil determined the factors that had the greatest influence on wheat (Triticum aestivum) response to phosphorus fertiliser. Rainfall prior to sowing and soil pH were important in low phosphorus buffering soils, and wheat response to fertiliser P was closely related to plant-available P in high buffering soils.

Omega-3 levels in pasture-fed beef and lamb are related to its availability in the forage plants grazed by livestock. We measured how omega-3 levels changed at different stages of plant development in four species of forages in south-eastern Australia. Omega-3 was richest in clover and least abundant in oats, diminishing as plants matured. Grazing forages at earlier developmental stages and maximising the amount of crude protein available for growth will increase the amount of omega-3 in plant material.

Applying concentrated bands of P to the subsoil (‘deep P’) increases plant P uptake in cropping systems reliant on stored soil water. However, we determined that sorghum (Sorghum bicolor) deep P responses can be limited by delayed N access, with biomass accumulation, productive tillering and P uptake maximised when N was concentrated in the 0–20 cm soil layer compared to at depth. Growers should ensure adequate N status of the upper soil profile to optimise sorghum deep P responses.