A few comments on Marketplace’s story page for the first piece in the Food for 9 Billion series talk about the need to control population. It’s an important point, and one of our upcoming pieces, reported in the Philippines, will address it directly. Homelands colleague Alan Weisman (author of the bestselling The World Without Us) is also working on a book about population and the world’s carrying capacity. We’re all curious to find out what he thinks can be done to slow growth.

Yesterday’s story was about the role of science in the effort to produce more food. I realize that’s not as innocuous a topic as it may seem. One of the current debates in the food world has to do with what some people consider to be an obsession with increasing the yields of major cereals. This raises fears of the spread of industrial agriculture controlled by big companies pushing genetically modified seeds. Even without this worry, a single-minded focus on yield seems to ignore the fundamental truth about why most people are hungry: not because there’s not enough food, but because they can’t afford to buy it. In the story, I try to paint a slightly more nuanced picture, highlighting the search for local solutions that take farmers’ welfare and interests into account.

That said, I do find myself believing that boosting production matters, especially for smallholders. Farms in sub-Saharan Africa are woefully unproductive, and malnutrition rates are staggeringly high. In many places, “the hunger season” lasts two or three months every year. Those tend to be the same places where the human population is growing the fastest. More food would help.

Boosting production doesn’t necessarily involve re-engineering plants to yield more. The piece takes a quick look at one attempt to do that (not using GM technology, as it happens, although the parallel effort to rejigger the rice plant does) and features the participatory breeding work of geneticist Fernando Castillo (who is wary of hybrids and anti-GMO). It also notes that scientists are trying to breed plants that resist pests and diseases (which can cut harvests in half in some countries) and that tolerate flooding and drought. But productivity is not all about breeding and seeds.

In fact one point I wish I had had time to make in the piece is that agroecological methods, which use combinations of crops and trees and animals, can actually produce more food per unit of land than monocultures. When managed right, these systems create synergies that reduce or eliminate the need for both fertilizers and pesticides. They can also lead to better diets, and provide important services that field crops alone can’t (like shelter, firewood, animal feed, fiber, and so on).

And, importantly, they help spread risk, not only of bad harvests but also of price drops that come with bumper crops. Producing oodles of corn or tomatoes or whatever tends to drive prices down, especially if everybody else is doing it at the same time. But agroecology is trickier than it sounds, and techniques and components vary from place to place. Millions of farmers in poor countries are using polycultures now (it’s the traditional way to farm in most places), but many of those systems are performing pretty poorly.

Anyway, complicated stuff, and I don’t pretend to understand all of it. That’s one of the great benefits of being a journalist—you get to learn along the way!