In order to feed billions of people on Earth today – and the billions more expected by 2050 – we need a second Green Revolution. That’s according to Dr. Jonathan Lynch, professor of plant nutrition at Penn State. He explained that the Green Revolution of the 1960’s was spurred by agricultural advances.
Jonathan Lynch: The first Green Revolution was using fertilizers and irrigation to improve yields.
Lynch said the second Green Revolution can’t depend on irrigation or fertilizer. He said that’s because many farmers in developing countries can’t afford either. To grow more food under tough conditions affordably, Dr. Lynch said, we’re going to have to breed plants with improved roots.
Jonathan Lynch: The roots are the part of the plant that take up water and nutrients. So if you want a plant that is going to be better at getting water and nutrients, you’ve got to have better roots.
Working with staple crops like beans and corn, Lynch identifies which root traits – like deep, or shallow -will help plants get the sustenance they need.
Jonathan Lynch: For some nutrients like phosphorous which are in the top soil, we want shallow roots.
Lynch then collaborates with plant breeders. He said evidence suggests that just changing the seeds to varieties with improved roots can double or triple farmers’ yields. Lynch is using traditional breeding techniques (in other words, not using genetic modification) to achieve better roots for plants, and seeds for those new plants. He told EarthSky that the greatest need for increased agricultural productivity is in poor countries in Africa, Asia, and Latin America.
Jonathan Lynch: Soils are bad. They don’t have enough money for fertilizer. They’re prone to drought. They don’t have enough water for irrigation. Yet they are dependent on agriculture. They live off the land. They’re subsistence farmers. What can you do? The approach of going in and changing the seed is something they can do. They don’t have to learn any new techniques or borrow any money, it’s just a different seed.
Lynch said there’s a lot of diversity within the roots of plants, which give plant breeders many choices for creating new, more efficient seed varieties.
Jonathan Lynch: We have different types of branching patterns that are good. We have roots that are thin or roots that are thick. We have roots that have long hairs, microscopic hairs, that stick out from them that help get nutrients. So there’s a lot of genetic diversity. Those are kind of differences we’re trying to take advantage of.
He described how each plant’s roots can be tailored to its needs and environment.
Jonathan Lynch: In the case of plants that need more water or more nitrogen, those are things that go deep into the soil. Our idea is that we want roots that go cheap, steep and deep. They’re cheap roots, so they can grow very well, and they have a very steep growth angle, and they end up being very deep, so they can get that deep water and deep nitrogen.
Lynch said the process of changing a culture’s food source can be difficult. In addition to discovering which root systems work the best, scientists also have to learn what it takes for a new seed to be adopted by farming communities. They also have to be sensitive to the cultural implications of certain crop varieties.
Jonathan Lynch: We don’t want to say, stop growing your corn and start growing this corn from the U.S. We want to say, keep growing the corn you like but now we’re going to give you some seeds just like that, but have better roots.