Soil Boron Toxicity (proportion of land affected)

Boron is an essential trace element occurring naturally in soil, but is toxic to many agricultural plants at high concentrations. High boron levels are often associated with windblown deposition of marine sediments, lower rainfall areas and impermeable clay layers (due to reduced leaching). Mapping shows the proportion of land with boron toxicity in the upper 100 cm of soil, while detailed proportion data are supplied for calculating respective areas of each boron toxicity class (spatial data statistics).