Crop growth module

[julieshortridge]

Next steps: @sumanager56

• [ ] simple crop representation (within SWAP) changed from grass to corn
  • [ ] run simulations
  • [ ] identify key differences in simple versus WOFOST representation, in terms of soil moisture and soil nutrient levels
• [ ] more complex corn simulations based on WOFOST

[sumanager56]

Changes made in corn.crp file compared to the grass.crp file. All changes were based on some values in the literature.

[sumanager56]

[sumanager56]

[julieshortridge]

Thanks Suman. On the ET plot above, I think we need to spend some time looking at how SWAP calculates ET through the growing season - you'd expect to see something resembling a peak in July/August (although still plenty of noise around it). I suspect this will boil down to the values in the crop factor table (lines 2-6 of the code you pasted above), but I need to refer to the manual to say for sure.

Also it is interesting to me that the actual ET are all on the potential ET line, which would suggest no water stress occurs in the growing season. We might expect that to be the case in the irrigated treatment but not the non-irrigated (although that will be easier to see in 2020 rather than 2021). But if our soil moisture values are staying high due to lower modeled drainage (I know this was the case with some of the plots you showed last time), that would be an understandable outcome.

[sumanager56]

That makes sense, Dr. Shortridge. I went back to check if there are reference crop data files for corn and found a detailed one. Previously, I was just changing some well-known parameters from a grass crop to a corn crop, but using more complex corn crop parameters, here's how the above plot looks. I think if we had input the irrigation scheduling data, the graph would look more reasonable since that would counter-balance the water stress that is showing up right now after the end of August.

[sumanager56]

@julieshortridge Dr. Shortridge, As suggested, I made necessary conversions in weather data (used Weather Stem data until August and time adjusted HOBO data for September and October) and updated the plantation and harvest date for corn. Here's how the above graphs looks with the new weather data!

[julieshortridge]

Great, thanks Suman. This is definitely an improvement. I'd suggest doing the following so we can better interpret these results:

1. On all plots (these and moving forward), just plot April - October so we can see that period more clearly.
2. On the soil moisture plot, can you plot just results at 12 and 24 inches? I think that will make it easier to incorporate the observed soil moisture data. Also are these in VWC percentages? I assumed that they were but the units on the graph (cm/cm3) have me a little confused.
3. On the lower graph with the rainfall, can you plot the daily rain amounts as vertical bars rather than a line graph?

[sumanager56]

Thank you, Dr. Shortridge, for the comments. Here's the modified version of the graphs.