New Research Explains Why Crop Rotation Works

A new research conducted by scientists at the John Innes Centre (JIC) helps explain the dramatic effect of crop rotation on soil health and yield. According to JIC Professor Philip Poole, changing crop species massively changes the microbes in the soil, which in turn help the plant get nutrients, regulate growth, and protect itself from pests and diseases.

During their research, soil was collected from a field and planted with wheat, oats, and peas. After wheat was grown, the soil remained largely unchanged and the microbes in it were mostly bacteria. When oat and pea were grown in the same sample, there was a huge shift from bacteria towards protozoa and nematode worms. After four weeks of growth, the soil surrounding wheat contained 3% eukaryotes, but it was 12-15% for oat and pea. This percentage is likely to be even more in the field where crops are grown for months.

The findings of this study could be used to develop crop varieties that encourage growth of beneficial microbes in the soil. JIC scientists are already looking at the possibility of engineering cereal crops that can associate with the nitrogen-fixing bacteria normally associated with peas.

For more details about this study, read the JIC news release available at: http://news.jic.ac.uk/2013/07/crop-rotation/. The results of this study were published in Nature's ISME Journal available at: http://www.nature.com/ismej/journal/vaop/ncurrent/full/ismej2013119a.html (doi: 10.1038/ismej.2013.119).