Growing roots in compacted soil

Erosion is carrying away millions of tonnes of the soil we depend upon to keep our crops alive, every year. To try to prevent soil losses, farmers have moved away from some traditional techniques, like deep ploughing, and they’re also planting short-lived “cover-crops” that protect the soil surface over winter. They then sow seed directly through these cover crops for the next season. The problem is that, without periodic deep ploughing, soils can become highly compacted. Plants don’t tend to send their roots through compact soils so well, meaning they miss out on nutrients, and this can dent yields. But now Nottingham University’s Malcolm Bennett has found that plants are actually doing this on purpose: they produce the gas ethylene from the tips of their roots, and if this accumulates, it turns off the growth, directing the root growth elsewhere. Turn off the sensitivity to ethylene though, and the plants grow through the compacted soils without any problems. Katie Haylor heard what he’s been up to...