Improved plant efficiency, not just yield, vital to crop sustainability

A second Green Revolution, focusing on plant efficiency rather than the yield goal of the first revolution, will be vital to managing sustainable crops that can be used to reduce world hunger, according to Jonathan Lynch, plant nutritionist for Pennsylvania State University.
The first revolution, according to Lynch, concentrated on soil inputs like fertilizers and irrigation. While the results worked for regions with good soil quality, many of the poorest nations also have to contend with poor soil — a situation that necessitates a different approach. "What we need, instead of plants that respond to fertilizers, are plants that can do well in low-input, low-fertility environments," said Lynch. Plants that can more efficiently acquire nutrients from the soil could save money, help the environment and result in more food for more people.
Efficient roots are the crux of the matter, according to Lynch, but finding the solution is complex. "To just say that you want more roots — that's the wrong answer," said Lynch. "Roots use up carbon and other resources. By having more roots, you have less yield. What you want somehow is a root system that's doing just the right thing at the right time in the right place."
Experiments in breeding for yield at low fertility has been successful where attempted, but many more studies need to be done. "The bottleneck right now is phenomics — identifying those root traits that are important and then, what's more difficult, understanding how they interact with one another," said Lynch. "There are very few people doing this kind of work. It's amazing to realize at this point how little we still know."