This work is contributing to several different research projects that focus on growing rice using less water. When rice soils are drained, nutrient availability and pathogen activity change. We are working to understand and predict problems with root health and plant vigor that will likely occur when water is restricted in rice cropping systems. We are working with rice breeders at the International Rice Research Institute and National Agricultural Research personnel in India, Nepal, Bangladesh and Pakistan to help them understand soil and root dynamics, so that they may focus their selection programs more productively.
impact statement issue
The land and water resources needed for producing crops are decreasing globally, while the demand for food to feed the growing world population is increasing. This means that approaches must be devised to grow more food using less land, water and other natural resources. The new 'aerobic' rice varieties being developed are meant to address the need to produce more rice using less water. It is critical for rice breeders to recognize that changes in water availability will not be the only environmental constraint to crop productivity that will be encountered in 'aerobic' cropping systems. In order for these new varieties to succeed, a better understanding of the concomitant changes in soil quality, root health and nutrient availability that may occur as a result of changes in soil redox potential is required.
impact statement response
We are developing protocols for evaluating changes in soil health, including increases in soil pathogen populations, changes in soil organic matter and changes in nutrient availability that occur when rice soils are drained. We are working to educate plant breeders in this area so that they can better select rice varieties that can withstand these soil constraints. An international training workshop was held for participants in this ADB funded project, with future training in root health issues planned. In addition, a team has been put together to examine the success of current practices that are being promoted, such as alternating wetting and drying and the System of Rice Intensification. A broad-based survey is planned for the near future, followed by focused research on farms and research stations in South Asia.
impact statement summary
Water is a limited resource with increasing multi-purpose uses. Rice production uses more water than any other crop. Means are being sought to get "more crop per drop". Among practices being examined are aerobic rice, alternating wetting and drying and the System of Rice Intensification. We are working to understand changes that occur in the rice rhizosphere during periods of wetting and drying and how these changes affect nutrient availability and retention, greenhouse gas emissions, and crop yield.
Other private funding
Asian Development Bank, International Rice Research Institute.