After more than 9,000 years rice farming has suddenly made a great leap forward in terms of productivity. A new report in the journal Nature Sustainability chronicles the agronomic, economic, and environmental outcomes of deploying perennial rice cultivation in southern China and Uganda.

Farmers are adopting the new perennial rice because it’s economically advantageous for them to do so. By not having to plant twice a year, they save a lot of labor and time.

The researchers developed perennial rice through hybridization, crossing an Asian domesticated annual rice with a wild perennial rice from Africa. Taking advantage of modern genetic tools to fast-track the process, the team identified a promising hybrid in 2007, planted large-scale field experiments in 2016, and released the first commercial perennial rice variety, called PR23, in 2018.

The international research team spent five years studying perennial rice performance alongside annual rice on farms in China. With few exceptions, perennial rice yield was equivalent to annual rice over the first four years. Yield began to drop off in the fifth year due to various factors, leading the researchers to recommend re-sowing perennial rice after four years.

Importantly, because they didn’t have to plant each season, farmers growing perennial rice put in almost 60% less labor and spent roughly half as much on seed, fertilizer, and other inputs.

The economic benefits of perennial rice varied across study locations, with profits ranging from 17% to 161% higher than annual rice. And even at times and places when perennial rice suffered temporary yield dips due to pests, farmers still achieved a greater economic return than by growing the annual crop.

Although they’ve already conducted on-farm testing and released three perennial rice varieties as commercial products in China and one in Uganda, the researchers aren’t done refining this crop.

They plan to use the same modern genetic tools to quickly introduce desirable traits such as aroma, disease resistance, and drought tolerance into the new crop, potentially expanding its reach across the globe.

While early findings on the environmental benefits of perennial rice are impressive and promising, more research and funding are needed to understand the full scope of perennial rice’s potential.