Abstract:
A field experiment in the "winter green manure-double cropping rice" and the "winter planting and breeding-double cropping rice" was conducted to measure the CH
4 and CO
2 emissions under different planting and breeding systems. The gas emissions were measured using the static chamber plus a greenhouse gas analyzer. The correlation between CH
4 and CO
2 emissions and main environmental factors and plant factors was also analyzed. The winter plants include ryegrass (
Lolium perenne) and milk vetch (
Astragalus sinicus). The goal of this rotation system is to return green manure and chicken manure to soils and reduce the application amount of fertilizers during the rice growing period. The results shows that compared with the winter fallow-double cropping rice, winter planting green manure or planting and breeding had no obvious effect on the seasonal variation of CH
4 and CO
2 emission in the paddy field, but affected the magnitude of the fluxes. The CO
2 cumulative emissions of the "milk vetch and grazing chickens treatment" were higher than the "winter fallow treatment", the "ryegrass treatment", the "milk vetch", and the "ryegrass and chicken treatment" by 150.23%, 2 034.43%, 102.08% and 98.68%, respectively (
P<0.05). Compared with the winter fallow-double cropping rice, the milk vetch and chicken treatment significantly reduced the cumulative emissions of CH
4 by 42.67% (
P<0.05), and "ryegrass and chicken treatment" and "milk vetch treatment" increased by 21.40% and 48.55%, respectively (
P<0.05). CH
4 flux was positively correlated with air temperature, and negatively correlated with dry weight and aboveground volume. There was a significant positive correlation between CO
2 flux, dry weight and aboveground plant volume. The CO
2 flux was negatively correlated with soil temperature and PAR.