In 2008, about 620 million tons of rice straw and about 125 million tons of husks (referred to as “residues”) were produced in Asia alone, and this quantity is increasing every year. In most places, these residues have no commercial value and are disposed off in various ways.
In intensive systems, where two or three crops are grown each year, the time for residue decomposition is very short and the remaining residues may disrupt soil preparation, crop establishment, and early crop growth. Although residue retention is essential for sustainable soil management of non-rice crops and mixed croppings systems (rice-upland crops), research in long-term experiments has shown that complete residue removal has no negative consequences for the productivity, sustainability, and soil health of intensive double and triple-cropping rice systems.
However, where practiced, burning of rice residues causes severe air pollution in some regions. The alternative, residue incorporation into the soil, in turn causes methane emissions from rice fields, contributing to climate change.
Rice straw recycling
IRRI and its partners are conducting research on innovative uses of rice straw and husks, including bioenergy and biochar systems (for carbon sequestration and soil improvement).
Research on the modifications of the rice plant target tools to determine the digestibility of rice straw, and then use these tools in breeding programs. This work will be carried out together with the International Livestock Research Institute (ILRI).
Therefore, our research will provide rice straw that has increased digestibility for feeding to livestock, help to mitigate climate change through renewable and sustainable energy production, reduction of greenhouse gases, and through carbon sequestration. And in addition, all these products will generate new income opportunities for rice farmers and the rice-farming sector.