Yield Stability, Profitability, and Greenhouse Gas Footprint of Direct-Seeded Aus Rice Varieties in Bangladesh

Rice is the staple food for more than half the world's population, and in Bangladesh, it is the foundation of daily life and food security. For decades, farmers have relied on a specific method to grow rice during the dry winter season, known as Boro, which requires pumping vast amounts of groundwater to flood the fields. This process is expensive, drains local water supplies, and burns diesel fuel, releasing significant amounts of greenhouse gases into the atmosphere. As labor becomes scarcer and more expensive, and as water grows increasingly scarce, scientists are looking for a different way to grow rice that saves money, water, and the climate. One promising alternative is direct-seeded rice, where farmers plant dry seeds directly into the soil rather than raising seedlings in a nursery and transplanting them by hand. This method avoids the need for continuous flooding, which can reduce methane emissions and lower the cost of production. However, for this method to work, the rice varieties used must be able to thrive without standing water and must still produce enough grain to feed families and support farmers' livelihoods.

A team of researchers set out to test this idea in the northern regions of Bangladesh, specifically in the districts of Rangpur and Rajshahi. They wanted to know if recently developed rice varieties could succeed when grown using dry direct seeding across different years and weather conditions. The study focused on five specific types of rice, including a standard variety that farmers currently use as a reference point, a benchmark variety known for its performance, and three newer candidates. The researchers planted these varieties in farmers' own fields over three consecutive growing seasons, from 2023 to 2025. By growing the rice side-by-side in real-world conditions, they could observe how each variety handled the local soil, rainfall, and temperature while measuring not just how much grain they produced, but also how much profit they generated and how much carbon dioxide equivalent they emitted per kilogram of rice.

The results revealed that not all rice varieties are created equal when it comes to this new farming method. One variety, named BRRI dhan98, emerged as a clear standout. In the Rajshahi region, this variety produced significantly more grain than the traditional farmers' choice, offering a yield advantage of about 20 percent. It also outperformed the benchmark variety by roughly 10 percent. In the Rangpur region, a different variety, BRRI dhan75, performed slightly better, showing that the best choice depends on the specific local environment. Despite these regional differences, BRRI dhan98 consistently delivered the highest overall yields and the greatest financial returns across the entire study area. The researchers calculated the benefit-cost ratio, which compares the money earned from selling the rice against the total cost of growing it. Both the top-performing varieties, BRRI dhan98 and BRRI dhan75, showed higher ratios than the traditional option, meaning they were more profitable for the farmers.

Beyond the harvest and the wallet, the study also looked at the environmental footprint of each variety. The researchers measured the greenhouse gas intensity, which is the amount of emissions produced for every kilogram of rice harvested. They found that while the total emissions were somewhat similar across the different types of rice, the efficiency varied. The most productive variety, BRRI dhan98, had the lowest greenhouse gas intensity, meaning it produced the most food for the least amount of climate impact. In contrast, the traditional farmers' variety and another test variety produced less grain but resulted in higher emissions per unit of food. This suggests that by choosing the right high-yielding variety, farmers can actually reduce their environmental impact while increasing their income.

The study also highlighted the importance of stability. Rice farming is unpredictable, with weather patterns changing from year to year. The researchers used statistical tools to see which varieties performed consistently well regardless of the specific conditions in a given year or location. BRRI dhan98 showed strong adaptability, maintaining high yields across different environments. Another variety, BRRI dhan85, was noted for its stability, performing reliably even if it did not always produce the absolute highest yield. Conversely, the traditional variety used by many farmers and one of the test varieties consistently underperformed, producing lower yields and offering less economic benefit. This indicates that sticking with older, less efficient varieties could be a barrier to adopting more sustainable farming practices.

While the findings are encouraging, the researchers noted that the study had limits. The trials were conducted in only two locations over three years, which may not capture every possible weather scenario or soil type found across Bangladesh. They also pointed out that weed management remains a significant challenge for direct-seeded rice, as the lack of standing water can allow weeds to grow more easily. Success with this method will likely require farmers to have access to better tools for controlling weeds and to receive training on how to manage the crop effectively. Nevertheless, the evidence suggests that combining dry direct seeding with the right choice of rice variety can be a powerful tool. It offers a path forward for farmers in Bangladesh to grow more food with less water and labor, while keeping their operations profitable and their environmental footprint smaller. The key lies in selecting varieties that are not just high-yielding, but also well-suited to the specific conditions of the land they are planted in.