Effect of straw incorporation on aldehyde emissions from a maize cropping system: A field experiment

Aldehyde may occupy an important role in the volatile organic compound (VOC) emissions from soil and plant residue. However, aldehyde emission from agricultural soil as well as the effect of straw incorporation is poorly understood. Therefore, a field straw incorporation experiment comprising two treatments, (1) S0 (no straw incorporation) and (2) S1 (incorporation of maize straw at a rate of 9000 kg ha−1), was performed in a maize cropping system to characterize the emissions of aldehyde as well as to estimate the effect of straw incorporation on aldehyde emissions. Nine kinds of aldehydes were investigated and three emission dynamic modes were observed during the experiment. Total aldehydes emissions were significantly different (426.8 and 540.2 g ha−1 for S0 and S1, respectively). Generally speaking, decanal and nonanal had an obvious predominance in both treatments, taking up 33.1% and 29.2% of the total aldehydes emission for S0, and 30.4% and 28.4% for S1, respectively. In addition, the practice of straw incorporation significantly increased the emissions of the 9 kinds of aldehydes by 11.2%-103.3%, and the total aldehydes emission from incorporated straw alone was calculated as 2918.8 ng kg straw−1 h−1. These results showed that straw incorporation substantially influenced the emissions of aldehydes from the agricultural soil. Additionally, a rough comparison indicated that straw incorporation might not have much advantage over straw open burning in terms of reducing VOC (i.e., aldehyde) emissions. The results also suggested that environmental conditions (i.e., soil temperature, moisture and pH), especially soil pH, played an important role in aldehyde fluxes from the agricultural soil.