STUDY ON THE CHARACTERISTICS OF MOVEMENT AND LEACHING LOSS OF NO3-N IN LOU SOIL IN SHAANXI AND ITS INFLUENCING FACTORS

In Lysimeters the movement and Leaching Loss of NO3-N in Lou Soil (cumulic cinnamon soil) in Shaanxi and its influencing factors were studied. The results obtained from the above study showed as follows: 1.The relationship between the amount of NO3-N Leaching Loss and the depth of soil profile could be simulated by exponential formula as Y=7386.73e-0.02559x 2.The NO3-N could be leached down to the 200cm, 100cm. and 50cm depth of soil profile under the 629mm, 349mm and 174mm of accepted water respectively. 3.The most part of NO3 -N in soil profile was concentrated in 0-50cm of soil layer, the peak of which usually presented in 20~40cm. 4.The NO3-N Leaching Loss from 50 and 80cm depth of lysimeters and the NO3-N accumulation in 100, 120, 150, 200cm depth of lysimeters were N applied with 3 times 2 times 1 time. 5.The NO3-N Leaching out from 100cm depth of lysimeter was increased with the increase of N fertiizer used. 6.The NH4C1 presented the trend to promote the crop growth, increase N uptake and reduce the NO3-N Leaching Loss. 7.N fertilizer mixed with 0~15cm soil layer was higher efficiency than other methods of N applied.