“Rice farmers can decrease their nitrogen fertilizer and pesticide use by around 20%, and increase their yield by 10% by using the ‘three controls technology’ (3CT),” says Dr. Xuhua Zhong, crop physiologist at the Rice Research Institute of the Guangdong Academy of Agricultural Sciences (GDRRI). The meaning of “three controls” is controlling the amount of fertilizer, unproductive tillers, and diseases and insects. “This technology is now being used by around 40% of farmers in Guangdong Province in China,” says Zhong.
In 3CT, Zhong recommends the “4-2-3-1 principle,” an easier way for farmers to remember the proportion of nitrogen fertilizer to be applied at different growth stages of the plant. It means 40% of nitrogen fertilizer is applied during the basal stage, 20% at midtillering stage, 30% at panicle initiation, and 10% at heading.
“And another way for farmers to remember, I told them the ‘one-half, one, and two,’ in which nitrogen fertilizer is applied at basal, then a half month after, then one month after, and lastly, two months after transplanting,” says Zhong.
Zhong explains that “the core change in farmers’ practices, aside from the reduction of nitrogen fertilizer input, is that the 3CT postpones fertilizer application from the early growth stage to the middle and late growth stages.”
“With less use of fertilizer, the rice plant is sturdy, does not lodge, and is less prone to diseases such as sheath blight so use of pesticide is reduced,” says Zhong. “Thus, farmers can save on the costs of fertilizer, pesticide, and labor.”
Moreover, the 10%-increase in yield is significant as it is equivalent to an average of 0.6 tons per hectare.
The 3CT technology could help China increase rice production in the face of multiple challenges. Since the 1990s, China has experienced low and unstable yields, excessive use of chemical fertilizers and pesticides, environment pollution, and low profits, according to Dr. Zongyong Jiang, president of the Guangdong Academy of Agricultural Sciences. “These problems have been increasingly serious,” Jiang says.
In 2012, 3CT was recommended by the Ministry of Agriculture of China (MOA) for use in rice farming. It is now aligned with the program of MOA to reduce the use of chemical fertilizers and pesticides.
“It is now widely adopted by rice farmers,” attests Jiang. “Indeed, the three controls technology helps farmers save fertilizer input, increase grain yield, and achieve more profit,” says Jiang. “Due to 3CT’s significant contribution, the research team, headed by Xuhua Zhong, was awarded the first-class Science and Technology Prize by the Guangdong provincial government.”
“In recent years, GDRRI has been working with the International Rice Research Institute (IRRI) to develop a low-carbon and high-yielding technology, which aims to further reduce fertilizer use,” says Jiang. “The new technology is expected to lessen water use and greenhouse gas emissions.”
“Indeed, the project, Closing Rice Yield Gaps in Asia with Reduced Environmental Footprint (CORIGAP), has been an excellent platform for the collaboration between GDRRI and IRRI,” states Jiang.
“The extension of 3CT through partnerships under CORIGAP has been instrumental in reducing the yield gap in rice production from 39% to 21%. Most importantly, this increase in rice production is not only more profitable for farmers, the reduction in fertilizer and pesticide use is also an important plus for the environment,” reports Dr. Grant Singleton, IRRI principal scientist and CORIGAP coordinator.
“It is good to see the progress that they have done in China,” comments Dr. Carmen Thönnissen, senior advisor, Swiss Agency for Development and Cooperation. “It is great to see more and more the integration of yield and sustainability, and finding ways of optimizing the whole production system in order to reduce the ecological footprint of rice as much as possible.”
Image caption: Dr. Xuhua Zhong shows a rice plot that uses the 'three controls technology' in Gaoyao county, Guangdong, China