Dear Uday,

First, the DSSAT models do not respond to P or K.

As for N, it is possible that the non-fertilized (no N) peanut crop can
yield more because N-fixation is greater than when fertilized with 40 kg of
N which would inhibit nodule growth and N-fixation just long enough, so
that you would have poor nodulation at crtical time of pod growth.

Lastly, it is not good to run the model with water balance turned off, yet
N balance turned on.  Or was it done to specify optimum irrigation to
create "no water stress."

Ken Boote

At 08:18 PM 9/12/01 +0530, you wrote:
>Dear Members,
>
>I am using DSSAT 3.5 for peanut crop growth simulation. I have calibrated
>the model with one of my treatments which is without water stress and
>recommonded (N P K as 40:60:30) fertilizer input. The observed and
>simulated data for this perticular treatment are matching.
>
>I simulated another treatment keeping all the inputs same as above except,
>there was no fertilizer.
>
>I observed tnat the simualated Pod yield, total biomass and max leaf area
>and seed yield in case of treatment without fertilizer are higher compared
>to the treatment with fertilizer. In my opinion the treatment with
>fertilizer should show higher values.
>
>I will appreciate your comments on this please.
>
>Thanks.
>
>Uday