Root length input

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Posts: 4
Joined: Tue Jul 09, 2019 1:40 pm
Location: Denmark

Root length input

Post by joost » Tue Oct 01, 2019 8:14 am

Dear Jirka,

With soil coring in the field I have obtained the root length density (RLD; cm/cm3) for my crop. I want to use this as input in Hydrus, but I am not sure what is meant by "Root (1/cm)". If I just do 1/RLD i get a large number for depths where my root length density is very small, and I don't know if that is correct.

Kind regards,

Posts: 5268
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Root length input

Post by Jirka » Tue Oct 01, 2019 3:14 pm

The Beta function describing the root distribution with depth (in the GUI denoted as "Root [1/cm]") is a function that describes the proportional distribution of potential root water uptake (root distribution) over depth. It does not have any actual values, i.e., it is a relative function. The program integrates entered values and normalizes them so that the integral of this function over the entire rooting depth is equal to one. See the manual for the mathematical description of root water uptake. J.

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