Study On The Harmless Fertilization Of Celery

The effect of different fertilizer variety, different application amount and method, different fertilizer compounds on celery (Apium graveolens L) growth, yield and quality was studied by the pot experiment and field experiment. The result as follow:There was curvilinear correlation between yield and N fertilizer rates. When the application quantity of nitrogen fertilizer was in the rang of 0~150mg/kg, the yield of celery was increased significantly with the increase of application quantity of nitrogen, more nitrogen application beyond this level will lead to reduce of yield. Chlorophyll , NRA and nitrate content was positively related to the application quantity of nitrogen. When the application quantity of nitrogen fertilizer was in the rang of 0~100mg/kg, the content of vitamin C and soluble sugar of celery was increased with the increase of application quantity of nitrogen, more nitrogen beyond this level will lead to reduce the content of vitamin C and soluble sugar. There was correlation between the content of vitamin C and N fertilizer rates. Under the same nitrogen, properly increasing the proportion of base nitrogen could promote the growth of celery, the proportion of dressing nitrogen had little using on celery's growth. When the ration of based and dressing nitrogen was 1 '?1, Chlorophyll, NRA, Vitamin C and soluble sugar was highest. Increasing the frequency of nitrogen could improve the content of Chlorophyll and Vitamin C. The lower the ration of dressing nitrogen, the higher the content of soluble sugar. The nitrate of dressing fertilizer one time was lower than two times'. The more nitrogen or later applying time of nitrogen, the higher nitrate content.The field experiment result showed that urea or ammonium chloride compounding with ammonium nitrate could significantly increase the yield of celery, ammonium chloride, ammonium sulfate or their combination could decrease nitrate content of celery, reduce soil nitrate accumulation.In three kinds of organic manure ,oil cake, chicken excrement, pig dung, chicken excrement and pig dung could apparently improve the plant height of celery , oil cake had little impact. Chicken excrement could apparently increase the yield, but pig dung and oil cake reduced the output of celery. The three kinds of organic manure increased Vitamin C and soluble sugar of celery, The effect on quality followed the order, chicken excrement>pig dung>oil cake. organic manure could significantly reduce the nitrate content of celery, the degree reached 7.1 % ~53.1 % , The effect on nitrate followed the order, chicken excrement>pig dung>oil cake. The heavy metal elements of Pb, Cd, Cu, Zn in leaf and petiole of celery were significantlylowered the national standard. So the application of organic manure did not cause the heavy metal pollution on celery. The heavy metal elements of Cu, Zn in leaf were increased significantly with the increase of pig dung. These results indicated that the celery would be polluted by heavy metal elements of Cu, Zn, under the condition that lots of pig dung was applied for long time.Phosphate fertilizer could evidently enhance the yield of celery. The effect on yield followed the order, ammonium phosphate>KH2PO4>superphosphate. When the application quantity of phosphate fertilizer was enough, the content of nitrate decreased 9.2%-26.2%, The effect on nitrate content followed the order, ammonium phosphate >K.H2PO4> superphosphate. The application of phosphate fertilizer did not cause the heavy metal pollution, the heavy metal elements of Pb, Cd, Cu, Zn in leaf and petiole of celery were significantly lowered the national standard.The orthogonal design of fertilizer compounds showed that fertilizer types influence the growth and the nitrate content of celery. The effect on growth followed the order, urea> potassium sulfate> lime>oil cake, the effect on nitrate content followed the order, urea>oil cake>potassium sulfate>lime. With the increase of the application of urea, the nitrate content of celery rapidly increased. With the application of...