Mass flow and diffusion processes determining nutrient bioavailability to roots in soil
Figures are generally photos, graphs and static images that would be represented in traditional pdf publications.
This figure is based on the work of Stanley Barber who is largely responsible for demonstrating the mobility of nutrients in soil and how these relate to root system architecture. Ions are said to be diffusion limited when they buffer strong on soil particles due to microscopic exchange sites on mineral crystals interacting with ionic charge. Mobile nutrients and water are said to be supplied by mass flow, they simply flow from soil to root surface due to transpiration and water potential gradients.
D1 = diffusion from solution to root surface
D2 = diffusion from particle to root surface
D3 = diffusion among exchange sites on particle
D4 = diffusion from particle to solution
MF = mass flow