Cover crop simulation

[Arjun Thapa]

Dear Dr. Luca,

I am trying to simulate flow, sediment, Total Phosphorus, and Total nitrogen in watershed scale using ArcAPEX first and then APEX Editor. I calibrated the model based on the measured value using APEXCute, then manually, based on the measured value and water balance in the Out file. I tried to simulate flow, TP, and TN load implementing scenario-based cover crops using the same calibrated file and parameters. Our hypothesis is implementing a cover crop would reduce the flow, sediment, TP, and TN. However, right now our calibrated model does not show pollutant load reduction.  I have not changed anything using the calibrated model's parameter except adding winter wheat to the management file. The attached .out file shows that ET is more in cover crop field, which is supposed to be, however, DPRK is low. I have been working for a long to figure out why winter wheat (cover crop) is not helping to reduce pollutants during simulation, and till now, I have not had success.  Due to data confidentiality, I could not share all the files in this email, but I will share them with your personal email.

I would really appreciate your help!

Sincerely,

Arjun Thapa

[Luca Doro]

Dear Arjun,

I am wondering if the absence of impact of the cover crop is because the winter wheat is not growing, not growing enough, or if it is growing in the wrong period to prevent the nutrient losses.

Using the baseline scenario, see when the majority of losses occur to understand if the growing season of the cover crop should help in reducing them.

Luca