Hi,everybody.
I simulated the process of NH4-N to NO3-N and their transport in a vertical soil column(100cm). The time variable BC was set as following.
Time(h) Preci(cm/h) Evap. hCrita. CTop-1 CBot-1 CTop-2 CBot-2
0.001 1 0 100000 14.37 0 0 0
24 1 0 100000 14.37 0 0 0
24.001 0 0 100000 0 0 0 0
240 0 0 100000 0 0 0 0
<b>241 2 0 100000 14.37 0 0 0</b>
246 2 0 100000 14.37 0 0 0
247.01 0 0 100000 0 0 0 0
360 0 0 100000 0 0 0 0
<b>361 1 0 100000 0 0 0 0</b>
372 1 0 100000 0 0 0 0
373.001 0 0 100000 0 0 0 0
480 0 0 100000 0 0 0 0
I got a simulated result. But I have a question about the concentration of NO3-N at depth 30cm below surface.The concentration of NO3-N abruptly increased from about 8mg/L to 12mg/L at the time of 241 hour, and from 8.2mg/L to 12.3mg/L at the time of 361 hour.And then decreased to about 8mg/L and 8.2mg/L respectively. At the same time the concentration of NH4-N decreased abruptly at the two ahead time (241 and 361 hour).
Why did the concentrations of NH4-N and NO3-N change abruptly?
Any help please. Thank you very much.