The field of microbiology is experiencing a surge in research and development, particularly in the area of rice cultivation. With the global push towards water-saving rice, farmers are now adopting techniques that reduce or eliminate the need for flooded paddy fields, which are significant emitters of methane, a potent greenhouse gas. One such technique is direct seeding, where pre-germinated seeds are planted instead of transplanting small plants into flooded paddies. Another approach is alternate wetting and drying, which uses pipes to control water levels and reduce flooding.
Research has shown that these water-saving methods can promote the growth of beneficial microbes, such as arbuscular mycorrhizal fungi, which thrive in drier, more aerated soils. These fungi live inside plant roots and help extend the plant’s reach into the soil to collect nutrients, acting as natural biofertilizers. Studies have found that arbuscular mycorrhizal fungi are more likely to colonize rice roots in non-flooded conditions, with one study showing that up to 20% of the root was colonized in irrigated, non-flooded conditions.
The benefits of promoting arbuscular mycorrhizal fungi in rice cultivation are numerous. They not only help plants access nutrients but also provide resistance to pathogens and increased survival in harsh climate conditions such as drought. By encouraging these beneficial microbes, researchers hope to reduce the use of synthetic nitrogen fertilizers, which are a significant source of nitrous oxide, a potent greenhouse gas. Instead, farmers can use biofertilizers, which contain live beneficial microorganisms such as arbuscular mycorrhizal fungi to promote growth.
The International Rice Research Institute (IRRI) has developed a water-saving rice variety, IRRI 154, which has shown promising results in promoting arbuscular mycorrhizal fungi colonization. A recent study in Senegal found that arbuscular mycorrhizal fungi helped rice grown under alternate wetting and drying conditions to have increased resilience to changes in water and nutrient levels. As the world faces climate change and water shortages, promoting beneficial microbes like arbuscular mycorrhizal fungi could enhance the overall resilience of rice, a crucial crop for global food security. By supporting and boosting these microbes, researchers aim to create more sustainable and environmentally friendly rice cultivation practices.