Survey And Analysis On The Changes Of Nutritional Components In The Suburbs Of Nanjing City In Recent Decade

The Chinese cabbage was now generally from the original peasant cultivation began to change to centralized intensive cultivation,the production environment,human factors and directly affect the growth and nutrient content.because of the means of production investment is far greater than the other crop,if in accordance with the traditional planting methods,often there would lead production waste.This paper based on the year of 2005-2015 during the decade the outskirts of the city of Nanjing Chinese cabbage protein fat,calcium,iron and four kinds of nutrient components(two kinds of organic compounds,a common element and a trace element)statistics investigation of change,combined with climate change,the decade of soil pollution and human factors changes,changes in these three aspects,analysis the following results:1.The absorption of calcium and protein synthesis had certain correlation,but not significantly;Fat no correlation with other substances;The absorption of calcium and iron correlation was as high as 0.8.2.Climate factors in Nanjing area average illumination time was reducing year by year,protein,fat,calcium,iron with the four kinds of nutrition components in annual average sunshine time relationship is not big,but the amount of annual average sunshine sharply reduced nutrients.Temperature change on the nutrition components in produce certain effect,namely the temperature affected the absorption of nutrients and synthesis,fat,calcium,iron,protein content is the most easy to be affected by temperature.Interval period when the rainfall of 1000-1050-mm rainfall,protein,fat,calcium,iron,the nutritional components of all four into decline,but after over 1050 mm,four kinds of nutrients content pointed into a rising trend;When the precipitation over 1080 mm would be decreased nutrient content.In combination with 14 years temperature change can judge,in under the comprehensive influence of precipitation and temperature,the root absorption ability weak,too much rain caused synthesis ability,finally decreased nutrient content.3.Soil pollution situation changes,the selection of the more representative of cadmium and lead as a representative of the main pollutants.Cadmium pollution was more serious,Chinese cabbage nutrients generates more difficult,reducing the cadmium pollution index of protein,fat,calcium,iron content.When the lead pollution index keeps stable in successive years,the synthesis of nutrients was not affected,when the above 0.757 or pollution index in successive years exist volatility would be lowered the content of nutrients4.4.Human factors,the selection of pesticide residues exceeding the survey,as well as three aspects of fertilizer use and personnel to carry out a comparative analysis.The pesticide residues exceed the standard content of these four components directly affect the rate,although not directly prove pesticide effect,but could still be found,exceed the standard time many pesticide residues,the nutrient component content would be reduced,on the contrary,rise.The fertilizer and technical personnel,since 2012 to promote and guide the Nanjing municipal government,although these four kinds of nutrition component content decrease to a certain degree,but with the deepening,farmers the improvement of quality of Chinese cabbage in the four components had been gradually increased,therefore,the agricultural science and technology development still could not do without government support and guidance.