[Use efficiency and fate of fertilizer N in tomato field of Nanjing suburb].
Field plot and micro-plot experiments were conducted to investigate the use efficiency (UE) , fate, and loss of chemical fertilizer N in tomato field of Nanjing suburb. The results showed that the application of chemical fertilizer N did not show any benefit to the tomato yield, due to the adequate N supply from native soil and organic manure amendment. The UE of fertilizer N calculated by difference method ranged from 14.5% to 22.5%. In micro-plot experiment, 16.6% - 28.8% of applied urea 15N was recovered by the plant, and 34. 2% - 46.0% of it was lost. Applying fertilizer N increased the nitrate content in 0-100 cm soil layer, and 10% - 10.2% of urea 15N was leached to the depth below 40 cm at harvest time. N application increased the denitrification loss and N2O emission significantly, which occupied 5.50% - 6.01 % and 2. 62% - 4. 92% of the applied N, respectively. No ammonia volatilization was detected during the whole growth season. Reducing N application rate or applying coated urea could decrease the environmental risks of N application in vegetable fields, especially the risks from nitrate leaching and nitrification-denitrification loss.
Cao
Bing
B
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. caobing@baafs.net.cn
He
Fayun
F
Xu
Qiuming
Q
Cai
Guixin
G
D002681:China; D005308:Fertilizers; D018551:Solanum lycopersicum / Q000254:growth & development*; D009566:Nitrates / Q000032:analysis; D009569:Nitric Oxide / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D012987:Soil / Q000032:analysis*
D005308:Fertilizers; D009566:Nitrates; D012987:Soil; D009569:Nitric Oxide; D009584:Nitrogen