Study On The Effects Of Different Simulated Acid Rain Spray Ways On Growth, Physiology And Nutritional Quality Of Pakchoi

With the rapid development of world economy and the burning of various fuels,acid rain pollution phenomenon and the impact on the environment is graduallyincreasing. Acid rain has become a very serious global problem of environmentalpollution. After the reform and opening up, because of rapid development of China’seconomic and urban expansion intensifie air pollution, acid rain pollution is one of theimportant regional atmospheric environmental issues. China has become the thirdlargest acid rain area of the world, just behind Europe and North America. At present,the chemical composition of rain in China is still sulfuric acid. However, with thecontrol of SO2emissions and rapid increase of motor vehicle ownership, the contentof SO2decrease in the atmosphere while the content of NOxincrease gradually. It willlead to the ratio change of SO42-and NO3-. As a result, the chemical composition ofrain has being transformed to sulfuric-nitric acid from sulfuric acid in china.The domestic distribution of acid rain has obvious spatial and temporalcharacteristics: the main characteristics of spatial distribution is that acid rain in theSouth is serious than the North, and acid rain in the cities is serious than rural areas;time distribution is the seasonal characteristics, that precipitation pH in winter andspring is smaller than summer and autumn. Acid rain areas mainly concentrate uponalong the Yangtze River, south of the Yangtze River and east of the Qinghai-TibetPlateau. Acid rain areas gradually extend to the north of china, and acid rain intensitygradually increase, so acid rain pollution of the Northeast region has become moreserious. Northeast precipitation occurs mainly in summer and autumn, which are theperiod of crop growth. Pakchoi is one of the widely growing vegetables in Northeast,.and the effects of acid rain on Pakchoi is also more sensitive, so it is chosen for theresearch object.Although reports about impacts of acid rain on vegetables have been widelycoverage, on the effects of different simulated acid rain spray ways on Pakchoi havenot been mentioned yet. Therefore, Vegetables-Pakchoi was chosen as the researchobject in this study, which is the more sensitive to acid rain stress and is one of the widely growing vegetables in Northeast. Study on the effects of different simulatedacid rain spray ways on growth, physiology and nutritional quality of pakchoi.According to the master data about pakchoi obtained by the simulation experiment,the different response of the pakchoi on different simulated acid rain spray ways canbe explored, and the mechanism of the difference also can be analyzed. Theconclusions will be the scientific basis for opening study on acid rain andprecipitation for vegetable growth and development, and provide basic data andscientific basis for the effects of the acid rain pollution on various vegetables,simultaneously supply reference for the impact of acid rain and flooding onagricultural production.The results by simulating procedures of different acid rain spray ways on growthof pakchoi indicated that the visible injury of pakchoi leaves was obsorved whenoperation of pH3.5were conducted, the smaller of the pH value, the more serious theinjury symptoms were, and new leaves are more vulnerable and more serious than oldleaves. The damage of concentrated spray way of pakchoi are more serious than evenspray way. The effects of simulated acid rain on growth of pakchoi have a closerelationship with the pH value and spray ways, the higher the acidity of the SAR, themore significant the inhibitions were. The effects of one-off spray way on growth ofpakchoi are more serious than concentrated spray way and even spray way. Strongacid rain significantly inhibited the growth of pakchoi. However, weak acid rain couldslightly stimulate plant growth or cause no significant impact. Acid rain and sprayways can significantly reduce the fresh weight of pakchoi. And synthesis of dry matterof pakchoi was inhibited. Different acid rain spray ways can inhibit growth anddevelopment of plant, cause decrease in stem and root length.The results by simulating procedures of different acid rain spray ways onphysiology of pakchoi indicated that different acid rain spray ways can inhibit thesynthesis of chlorophyll of pakchoi, resulting in decreased photosynthetic ability ofpakchoi. By the intensity of acid rain became increase, chlorophyll of pakchoidecreased gradually. When the pH value is the same, the physiological effects of evenspray way on pakchoi are minimal, followed by concentrated spray way. Water were supplied at once by One-off spray way, causing the greatest impact on the pakchoi.With the increase of spray acid rain time and the number of spraying, the overallcontent of chlorophyll is increased, but the decreasing amplitude is also increasing.When pH≤4.5, three spray ways all can damage the plasma membrane system of thepakchoi, inhibit the synthesis of photosynthetic pigment, and reduce thephotosynthetic rate. And pH=2.5, the effects of three spray ways on chlorophyll ofpakchoi are greatest, which the effect of one-off spray way is most obvious in.The results by simulating procedures of different acid rain spray ways onnutritional quality of pakchoi indicated that vitamin C and soluble sugar weresignificantly inhibited by simulated acid rain. The stronger acid was, the moresignificant the inhibition would be.The different spray ways lead to the different sprayvolume and different spray frequency. The more a single spray volume and the longerspray interval, the more serious the effects of nutritional quality of pakchoi were. Bythe pH of acid rain became lower, vitamin C and soluble sugar of pakchoi leavesdecreased gradually. When the pH value is the same, the nutritional quality effects ofeven spray way on pakchoi are minimal, followed by concentrated spray way. Waterwere supplied at once and spray time interval was too long by One-off spray way,causing the greatest impact on the pakchoi. With the increase of spray acid rain timeand the number of spraying, the overall content of vitamin C and soluble sugar areincreased, but the decreasing amplitude is also increasing,and the affects are alsomore and more serious.