Hello Everyone,

I received a question from a fellow DSSAT user that I could not answer.  In
short he was asking why when he runs a legume experiment with the N switch
turned off he still sees N stress.

I ran the first treatment (no H2O or N stress) of IUCA experiment that came
with DSSAT and confirmed that this phenomenon occurred.

Does anyone know the reason for this?

Thank you in advance.

Brian

*SIMULATION OVERVIEW FILE

*RUN   1        : 0.25m ROW, NO WATER STRES
  MODEL          : CRGRO980 - SOYBEAN
  EXPERIMENT     : IUCA7901 SB    WAYNE, IRRIGATED &
NON-IRRIGATED
  TREATMENT  1   : 0.25m ROW, NO WATER STRES

  CROP           : SOYBEAN        CULTIVAR : WAYNE (3)        -  MATURITY
GROUP 3
  STARTING DATE  : MAY 15 1979
  PLANTING DATE  : MAY 15 1979    PLANTS/m2 : 16.0     ROW SPACING :  25.cm
  WEATHER        : IUCA   1979
  SOIL           : IBSB910026     TEXTURE : -99   - Ida Silt Loam
  WATER BALANCE  : NOT SIMULATED ; NO H2O-STRESS
  IRRIGATION     :
  NITROGEN BAL.  : NOT SIMULATED ; NO N-STRESS
  N-FERTILIZER   :
  RESIDUE/MANURE :
  ENVIRONM. OPT. : DAYL=     .00  SRAD=     .00  TMAX=     .00  TMIN=     .00
                   RAIN=     .00  CO2 = R330.00  DEW =     .00  WIND=     .00
  SIMULATION OPT : WATER   :N  NITROGEN:N  N-FIX:N  PESTS  :N  PHOTO  :L  ET :R
  MANAGEMENT OPT : PLANTING:R  IRRIG   :N  FERT :N  RESIDUE:N  HARVEST:M  WTH:M

*SUMMARY OF SOIL AND GENETIC INPUT PARAMETERS

  SOYBEAN    CULTIVAR :IB0003-WAYNE (3)          ECOTYPE :SB0301-MATURITY
GROUP 3
  CSDVAR :13.45  PPSEN  :  .25  EMG-FLW:19.50  FLW-FSD:14.80  FSD-PHM :28.00
  WTPSD  : .180  SDPDVR : 2.20  SDFDUR :21.00  PODDUR :14.00  XFRUIT  : 1.00



*SIMULATED CROP AND SOIL STATUS AT MAIN DEVELOPMENT STAGES

  RUN NO.  1    0.25m ROW, NO WATER STRES

    DATE CROP GROWTH   BIOMASS  LAI  LEAF   ET  RAIN IRRIG SWATER
CROP  N  STRESS
         AGE  STAGE     kg/ha         NUM.  mm   mm    mm    mm   kg/ha
%  H2O  N
--------------------------------------------------------------------------------
  15 MAY    0 Start Sim      0   .00   .0    0     0     0     0    0  .0
.00 .00
  15 MAY    0 Sowing         0   .00   .0    0     0     0     0    0  .0
.00 .00
  28 MAY   13 Emergence      8   .01   .0    0     0     0     0    0 5.1
.00 .08
  28 MAY   13 End Juven.     8   .01   .0    0     0     0     0    0 5.1
.00 .08
   7 JUN   23 Unifoliate    16   .03  1.2    0     0     0     0    1 4.8
.00 .47
  10 JUN   26 Flower Ind    21   .04  1.6    0     0     0     0    1 4.8
.00 .03
  13 JUL   59 First Flwr  1301  2.22  9.3    0     0     0     0   52 4.0
.00 .00
  28 JUL   74 First Pod   3652  4.62 13.0    0     0     0     0  133 3.6
.00 .00
   9 AUG   86 First Seed  5665  5.46 16.2    0     0     0     0  194 3.4
.00 .00
  21 AUG   98 End Pod     6807  4.80 18.6    0     0     0     0  226 3.3
.00 .00
  26 AUG  103 End Msnode  7373  4.46 19.4    0     0     0     0  241 3.3
.00 .00
  26 AUG  103 End Leaf    7373  4.46 19.4    0     0     0     0  241 3.3
.00 .00
  10 SEP  118 Phys. Mat   8814  3.42 19.4    0     0     0     0  300 3.4
.00 .00
  22 SEP  130 Harv. Mat   7115   .22 19.4    0     0     0     0  265 3.7
.00 .00
  22 SEP  130 Harvest     7115   .22 19.4    0     0     0     0  265 3.7
.00 .00