But Fengyi Hu didn’t give up. In 2012, he set out to try again. He got 21 researchers on board and began his experiments. Finally, 5 attempts later, they did it. They managed to create perennial rice — a lab-developed cross between domestic Asian rice called Oryza sativa and its perennial African relative Oryza longistaminata. They called it PR23! (View Highlight)
Note: Q: What is PR23?
A: PR23 is a lab-developed cross between the domestic Asian rice Oryza sativa and its perennial African relative Oryza longistaminata.
Now there’s a caveat. Just because the name says ‘perennial’, it doesn’t really mean that the rice will last forever. Rather, it means that PR23 will last a long time. Farmers can plant the crop just once and reap about 8 harvests (or go 4 years) without resowing it. The rice can be harvested without killing the plant and the rice simply continues to grow. (View Highlight)
Now on the face of it, cost savings may not be apparent. Because the first sowing costs pretty much the same as any other variety of rice would. It needs the same machines, the same labour, everything. It’s only in the second sowing season that the true benefits appear.
You see, rice seeds are normally first sown in a nursery before they are replanted in ploughed fields. Since perennial rice didn’t need a second round of resowing, it didn’t need to depend on nurseries, didn’t require reploughing and also didn’t have to be transplanted from nurseries to fields.
Also, the soil doesn’t have to be tilled each year. And there’s no replanting. So costs inevitably drop. In fact, farmers saved upwards of $1200 per hectare in labour and non-labour costs. And perennial rice saved about 68 to 77 days of labour. The researchers say that perennial rice cuts cost by 50% in years when farmers don’t have to plant it. (View Highlight)
Also, perennial rice is quite a hardy crop. One that has deeper and stronger roots. One that can self-grow. But also, one that retains much more water than the regular rice crop. That means, in regions where paddy cultivation is dependent on rainfall and is prone to droughts, growing the PR23 can help you save on irrigation costs too. (View Highlight)
To put things in perspective, regular or annual rice varieties require tilling the soil once a year before it receives seeds. This means that the soil’s surface is regularly disturbed. And it’s left exposed to water and wind erosion. Also, in the process of tilling, soil oxidising bacteria are disturbed. And that can create 51% more methane emissions than perennial rice. (View Highlight)
Reduced tilling also increases the organic carbon and total nitrogen composition in the soil. This simply means that crops can be healthier. They can tap into the abundance of nutrients in the soil to stimulate its regeneration. (View Highlight)
Some researchers suggest that since the soil isn’t ploughed regularly, it could become a breeding ground for fungi and pathogens. Also, weeds flourish in such fields and they require more herbicide treatments (which actually add to the cost). Then there’s the insect problem — after harvesting, these critters can remain in the crop. They could then transmit viruses when they feed on the regenerating crop. And finally, when the 4 year period is over, taking out the strong roots to replant the rice could actually be a tougher task. Again, it could lead to labour demanding higher rates for the effort. And maybe some of that cost savings won’t add up. (View Highlight)
PS:Fun fact —All rice is perennial to a certain degree. Rice actually grows again after a harvest without the need for replanting. The downside is that the second harvest usually has a low-quality yield which is why farmers replant every year. (View Highlight)
