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APSIMInitiative / APSIM710

APSIM
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Nitrate calibration for each layer (up to 60 cm soil depth) #1793

Open brijesh10760 opened 4 years ago

brijesh10760 commented 4 years ago

Respected Sir/Ma'am I am Brijesh from Division of Agricultural Physics, IARI, New Delhi, India.I am simulating nitrate content for each soil layer using APSIM model. Model is calibrated for crop phenology, yield, biomass, LAI, soil moisture and soil temperature but model is not simulating nitrate content properly. I need your suggestions for following questions- (1) parameters or coefficients need to be change so, that model can simulate nitrate properly. (2) I applied urea fertilizer twice (on 46 and 85 day after sowing) during crop period. But , model is not predicting nitrate properly on 85 DAS (picture). Nitrate content should be increase after fertilizer application but it is continuously decreasing, as we can see in the attached picture.

image

Thanking You Sir.....

peter-devoil commented 4 years ago

Hi, - you'll find that apsim generally has variables that allow you to find where nutrient flows are going - in this case I can think of two: towards the plant, and as a solute draining down the profile. The first will be called "wheat.n_uptake" - a sum over the whole profile, alternatively [no3|nh4]uptake which is on a layered basis. The second will be called "flow[no3|nh4]" and again is layered.

In general, it's good practise to identify which equation in apsim is "wrong" before attempting to adjust parameters - in this case, there are many parameters that influence N content, but only a few are candidates for sensible modification

PS - that's about the limit of my understanding!

sarahcleary commented 4 years ago

@brijesh10760 - are you still having the same issue?