Abstract: The effects of different nitrogen fertilization levels on yield of cucumber, the soil nitrate2N content and the soil solution nitrate2N concentration were studied by the experiment in Tongzhou of Beijing. The results sho wed that cu2 cumber yield was highest at the N rate 260 kg/ ha, also got best gross economic returns at this N rate, it was the best N rate input. This studied evaluated the soil nitrate2N content under different nitrogen fertilization levels, the results showed that the environment capacity of the soil to N fertilizer was preliminarily determined as N 260 kg/ (ha#year).An end2of 2 season soil NO3^-2N test in the 0- 90 cm appeared tobe capable of evaluating cucumber N management practices. Nitrate N concentration in the soil solution increased as the total ofN applied to the soil.A significant relationship was found be2 tween the total mass of NO3^-2N in the 019m soil profile following harvested andthe amount ofNO3^-2N concentrations in the 019 m. It would be useful topredict the potential for nitrate(NO3^-) leaching to the drinkingwater through the amount of NO3^-2N concentrations test in the 019 m.

Key words: Environment capacity, Rate of fertilizer applied, Soil nitrate2N, Soil solution

CLC Number: 

• S143.1