The impacts of radiation effects of atmospheric aerosol on rice production in the Yangtze Delta Region

Abstract

With the rapid pace of industrialization and urbanization, there is a significant increase of the atmospheric aerosol concentrations. The high aerosol concentration has already had negative impacts on ecological environment, especially on crop production, becoming a focus of attention by scientific communities. So far, no dedicated experiments on the impacts of aerosols radiation effects to crop's growth has been conducted yet. This paper intends to assess the impacts through the numerical simulations. In the research, a crop model (Crop-DNDC) is coupled with aerosol radiation effects model. The study is targeted to the rice, a primary crop grown in the Yangtze River Delta region, and the simulations focuses on the impacts of the changing atmospheric aerosol concentrations on rice growth and yield in the region with the coupled model. As the first step, analysis on radiation changes over the Yangtze Delta Region is made. Then the atmospheric aerosol radiation effects model is coupled with Crop-DNDC, which is used to simulate the impacts of radiation effects on rice growth in the region due to changes of aerosol concentration which is expressed by atmospheric optical depth (AOD). It is found that under the current average atmospheric aerosol concentration status over the Yangtze Delta Region (AOD = 0.78), PAR for rice growth period may be reduced by 17.6%, compared with that without the atmospheric aerosol (AOD = 0). Similarly the grain yield of rice may decrease by 9.3%. Our finding shows that if the atmospheric aerosol optical depth is doubled, PAR for rice could be reduced by additional 15.7%. Consequently, the rice grain weight could be decreased by additional 8.1%.