Scientists from the University of Bremen, Germany and Chinese Academy of
Sciences, China, conducted a study to investigate the degradation of
transgenic Bt rice straw when incorporated into paddy soils. The research is
published in the Journal of Environmental Management.

Incorporation of rice straw in paddy soils after harvest is a common
practice to fertilize or improve the structure of the soil. The use of straw
from transgenic Bt rice poses a concern because of potential risks such as
integration of Bt proteins in soil. Thus, decomposition of Bt rice straw and
degradation of Bt proteins, and the condition of microbial communities were
observed under laboratory conditions.



Results showed that Bt rice straw caused a slight change on soil respiration
and methane emissions in two types of paddy soils (silt loam soil and silty
clay soil). There were also differences in the cumulative emissions of
carbon dioxide between two paddy soils. Bt proteins Cry1Ab/Ac were degraded,
though at varied rates in differently textured paddy soils. The presence of
rice straw led to the increased abundance of soil microorganisms.



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