Research Progress on the Carbon and Nitrogen Sink of Duckweed Growing in Paddy and Its Effects on Rice Yield
Duckweed(Lemna minor L.)is a floating microscopic plant that is usually found in standing water.Climate change is characterized by rising temperature,which is mainly due to increasing atmospheric CO2 concentration,and it poses potential risks to food production.Owing to factors such as climate warming and/or the eutrophication of water,duckweed growth in paddy fields has shown an increasing trend year by year in China.This paper focused on the impacts of duckweed on paddy fields and highlighted some vital trends.Duckweed reduced the water temperature of paddy by 0.86-2.76 ℃ and the pH value by 0.10-0.45,changed the structure of microbial community,reduced the NH3 volatilization by 18.2％-59.0％,and increased the nitrogen utilization rate by 17.2％-78.0％.As a result,the nitrogen sink of paddy increased and the rice yield rose by 9.0％-34.6％upon duckweed growing in paddy.Duckweed grew and reproduced rapidly,and its annual biomass could reach 8×103-13× 103 kg·hm-2,making its carbon sink almost equal to that of rice in the same season.The mutualism between duckweed and rice was greater than its competition,and the coexistence of duckweed and rice in paddy showed an adaptation of the rice field ecosystem to environmental changes.Future research in this field should focus on the effect and its mechanism of duckweed on the paddy environment changes,rice growth,yield,and quality,and the risks which might bring to the paddy fields,especially the interaction with environmental factors(elevated temperature and CO2 concentration,etc.).Such research would provide theoretical support for the sustainable agricultural development of rice farming technology based on biological collaboration,such as rice-duckweed,which can adapt to future changes in climate and environment.
duckweed(Lemna minor L.)ricecarbon sinknitrogen sinkyield
国家科技期刊平台
NSTL
万方数据
维普
