Straw phytolith for less hazardous open burning of paddy straw

Abstract

Rice production helps feed at least half of the world’s population but generates approximately one billion tonnes of straw residue per annum. On-site open burning of rice straw after harvesting is common in recent times because there has been less demand for rice straw to use as fuel and fodder. Due to health and climate change concerns, open burning, which results in biomass losses, smog and emissions of green house gases, e.g., CO2, has been widely criticized and banned in many countries. Little is known about the positive benefits of straw burning, such as field care (eradication of biotic diseases) or nutrient cycling. Herein, we propose a new viewpoint in which the burning of rice straw followed by cycling of the burned materials, including silica material (so-called phytolith), into soil is demonstrated as a CO2-sequestration strategy via buffering the soil CO2 flux and coupling CO2 with the silicon cycle.