I do not know if it is the "most efficient", but we developed a "physically-based" soil moisture model and it is freely available on ResearchGate at the attached link.

You can find at the link all the references and material.

Good luck!

Data Soil Moisture Model (Matlab code)

I recommend HYDRUS, developed by USSL.  You will get a lot of support on line. 

I think the link below can help you: 

https://www.soil-modeling.org/models

https://www.soil-modeling.org/models

I recommend SALTMED model, developed by Dr. Ragab Ragab.Also you can choose non-crop condition in this model.

you can use the hydrus 1-D, if you want to work in a mono- dimensional