Effect Of Road Traffic Pollution On Rice

With the rapid development of rural road, the rice plants grown nearby the rural road are under the impact of road.Road traffic pollution consists of many factors. The heavy metal pollutants in the soil can not self-degrade and disappear, but will gather in the rice through the migration or conversion process. Its gathering will further threaten the human health through the food chain. Therefore, road traffic poses a potential threat to the terrestrial ecosystems and food security.In order to ascertain the impacts from rural road traffic pollution to the roadside crops, the pot experiment was implemented-by setting compartments according to the different distances to road verge and placing the pots to plant. The flows are:the photosynthetic parameters were determined in the end of tillering; the fresh rice leaves were collected twice to make the paraffin sections, and the organizational structure of leaves was observed through microscope; the agronomic traits were analyzed after the rice became mature; the heavy metal content in the rice samples was determined after drying. The main research results are as follows.(1) Road traffic pollution affects the leaf photosynthetic rate and respiration efficiency, mainly in the aspects of stomatal conductance, CO2 concentration, net photosynthetic rate and transpiration rate; the photosynthesis of rice leaves is affected more obviously as the plants are closer to the road.(2) The results after observation to the organizational structure of potted rice leaves show, road traffic pollution affects inconspicuously the bulliform cells and the vascular bundle form of leaves, but the array of superficial cells is changed.(3) Road traffic pollution inhibits inconspicuously the agronomic traits of rice plants in stem length, spike length, flag leaf length and width, maturing rate and dry weight, but affects the tillering rate, weight of 1000 grains and yield.(4) The results of determination to the content of Cd, Zn, Cu, Pb in heavy metal of potted rice show, rice plants with 15m and 50m to road verge are polluted in different degrees by heavy metal; those with 200m to road verge are affected inconspicuously.