Effect Of Nitrogen On Nitrate Accumulation And Quality In Leaf Vegetables

Leaf vegetables are easy to enrichment of nitrate,when nitrate absorbed in the human body most comes from vegetables.nitrate is the precondition of carcinogenic nitrosamines,at the same time,long-term intake will affect people health.Therefore,Chinese cabbage,Spinach,Garden chrysanthemum and Celery are seen as the test materials of this test,we research effects of nitrogen on nitrate accumulation and quality in leaf vegetables through some treatment like the different forms of nitrogen and ammonium nitrate ratio and different fertilizing time,what provides the theory basis for safe and stable manufacture.The following conclusions:(1)After applying different nitrogen treatment,nitrate accumulation in the body of leaf vegetables are with the trend of first increased and then drop during the growth time.Amide nitrogen of each treatment in the lowest,followed by ammonium nitrogen,nitrate nitrogen treatment is the highest;In nitrate accumulation of all of leaf vegetables,Garden chrysanthemum in the lowest,followed by Chinese cabbage and Spinach,Celery is highest.The NRA and root activity of each leaf vegetable are positively related with nitrate accumulation,the GSA has indirect relation with nitrate accumulation.After the use of different forms of nitrogen,in terms of soluble sugar and soluble protein of leaf vegetables,nitrate nitrogen and ammonium nitrogen fertilizer is higher,and the highest of four leaf vegetables is Celery;For VC content in leaf vegetables,the highest is nitrate nitrogen fertilizer,and the highest of four leaf vegetables is Spinach;In the aspect of expand the degree,leaf angle,fresh weight,dry weight and produce of leaf vegetables,for Chinese cabbage the highest is nitrate nitrogen fertilizer and for other leaf vegetables the highest is amide nitrogen fertilizer.(2)The use of different ratio of nitrogen in nitrate and ammonium can increase nitrate accumulation in the body of leaf vegetables.The treatment in the application of ammonium nitrate ratio as 1:1 in the lowest,followed by the ammonium nitrate ratio as 2:1;the ammonium nitrate ratio as 1:2 is the highest.In nitrate accumulation of leaf vegetables,Garden chrysanthemum in the lowest,followed by Chinese cabbage and Spinach,Celery is highest.The NRA and root activity of each leaf vegetable are positively related with nitrate accumulation,the GSA has not direct regularity.In terms of leaf vegetables soluble protein,soluble sugar,chlorophyll,and leaf angle,the treatment in the application of ammonium nitrate ratio as 1:1 is the highest,Spinach is the highest in four kinds of leaf vegetables;For the VC content of leaf vegetables,the treatment in the application of ammonium nitrate ratio as 1:1 is the highest,Chinese cabbage is the highest;In the aspect of expand the degree,fresh weight,dry weight and produce of leaf vegetables,the highest is The treatment in the application of ammonium nitrate ratio as 1:1,Celery is highest in four kinds of leaf vegetables.(3)Aftter the use of different fertilization period of nitrogen,for nitrate content in the body of all of leaf vegetables,basic fertilizer treatment is with the trend of first increased and then drop through the growth time,and disposable dressing treatment with growth shows a trend of first drop and then increased and second drop,and two dressing treatment with growth shows a trend of first increased and then drop and trend rises and falls again,and the first peak is higher than the second peak.In nitrate accumulation of leafy vegetables,the mixed application basic fertilizer and additional fertilizer in the lowest,followed by additional fertilizer treatment,basic fertilizer treatment is the highest;The ratio of basic fertilizer and additional fertilizer is 2:1,in the lowest,followed by the ratio represented as 1:1,the ratio represented as 1:2 is the highest;disposable dressing treatment is the lowest and two dressing treatment is the highest.The NRA and root activity of each leaf vegetable are positively related with nitrate accumulation,the GSA has not direct regularity.For the content of soluble sugar and soluble protein,leaf angle,fresh weight,dry weight and produce of leaf vegetables,the treatment is highest that the mixed applicational ratio of basic fertilizer and additional fertilizer as 2:1 and two dressing,Spinach is the highest of three kinds of leaf vegetables;For the content of VC and chlorophyll,and root activity of leaf vegetables,the treatment is highest that the mixed applicational ratio of basic fertilizer and additional fertilizer as 2:1 and two dressing,Chinese cabbage is the highest of three kinds of leaf vegetables.In brief,amide nitrogen treatment is the highst for the nitrate accumulation of leaf vegetables,but quality and produce are poor,while nitrate nitrogen is the lowest for the nitrate accumulation of leaf vegetables,but quality and produce are the best;For the nitrate accumulation of leaf vegetables,the treatment in the application of ammonium nitrate ratio as 1:1 is the lowestwith the best quality and produce;In terms of the nitrate accumulation of leaf vegetables,the treatment is lowest that the mixed applicational ratio of basic fertilizer and additional fertilizer as 2:1 and two dressing,with the best quality and produce.In agricultural production,therefore,we advise that the application of ammonium nitrate ratio as 1:1and the mixed applicational ratio of basic fertilizer and additional fertilizer as 2:1 and two dressing are the best.