topsoil

英 ['tɒpsɒɪl] 美['tɑp'sɔɪl]

What about supply? The three environmental trends—the shortage of fresh water, the loss of topsoil and the rising temperatures—are making it increasingly hard to expand the world's grain supply fast enough to keep up with demand.

The three environmental trends—the shortage of fresh water, the loss of topsoil and the rising temperatures—are making it increasingly hard to expand the world's grain supply fast enough to keep up with demand.