In the heart of South Australia, researchers are uncovering a hidden partnership that could revolutionize rice cultivation and offer significant benefits to the energy sector. Stephanie J. Watts-Williams, from The Waite Research Institute and the School of Agriculture, Food and Wine at the University of Adelaide, has been delving into the world of arbuscular mycorrhizal (AM) fungi and their potential to enhance the water use and phosphorus acquisition efficiencies of aerobically grown rice.
Traditionally, rice is grown in flooded fields, a method that, while effective, comes with substantial environmental costs, including significant methane emissions. However, aerobic rice cultivation—growing rice in well-drained, oxygen-rich soil—presents a more sustainable alternative. This method can increase grain water use efficiency, reduce methane emissions, and minimize phosphorus loss. But there’s a catch: rice plants in aerobic conditions often struggle to access water and nutrients as efficiently as they do in flooded soils.
Enter AM fungi. These microscopic organisms form symbiotic relationships with plant roots, enhancing their ability to absorb water and nutrients from the soil. Watts-Williams and her team set out to explore how these fungi could boost the performance of aerobically grown rice. “We found that inoculation with Rhizophagus irregularis, a type of AM fungus, increased grain water use efficiency in all four rice varieties we tested,” Watts-Williams explains. “On average, we saw a 14.4% increase, which is a significant improvement.”
The study, published in the Journal of Sustainable Agriculture and Environment, used a precision irrigation platform to apply watering treatments and monitor the growth of four commercial Australian rice varieties. The results were promising: not only did the AM fungi improve water use efficiency, but they also enhanced phosphorus acquisition efficiency and increased grain yield in two of the varieties.
One variety, Topaz, showed a particularly strong response to the AM fungal inoculation, with notable increases in both water use and phosphorus acquisition efficiencies. This suggests that the benefits of AM fungi could vary depending on the rice variety, highlighting the importance of careful selection when transitioning to aerobic rice production.
So, what does this mean for the energy sector? Methane is a potent greenhouse gas, and rice cultivation is a significant source of these emissions. By adopting aerobic rice cultivation and harnessing the power of AM fungi, farmers could substantially reduce their carbon footprint. Moreover, the increased water use efficiency could lead to significant savings in irrigation costs, making rice production more sustainable and economically viable.
But the benefits don’t stop at the farm gate. As Watts-Williams points out, “Enhancing the resilience of rice cultivation to climate change is crucial. With more efficient water and nutrient use, we can help ensure food security in the face of increasingly unpredictable weather patterns.”
The research opens up exciting possibilities for the future of rice cultivation. As we grapple with the challenges of climate change and the need for sustainable agriculture, the partnership between rice and AM fungi could play a pivotal role. By selecting the right rice varieties and leveraging the power of these microscopic allies, farmers could boost their yields, reduce their environmental impact, and contribute to a more sustainable future. The energy sector, in turn, could benefit from reduced methane emissions and increased water use efficiency, making rice production a more attractive and sustainable investment. The journey from lab to field is long, but the potential rewards are immense.