There wasn't enough room in the box to write "Physical Education" in full at the end, but I would do so, rather than abbreviating it.

I would use these terms, on the following grounds:

In Argentina, as in Spain, "maestro" is a primary or elementary teacher and "profesor" is a secondary or high school teacher. "Profesor" is also, of course, a teacher in higher education, but that's not relevant here.

We need to see what kind of qualifications these terms denote in Argentina. Lorena has cited a useful source on this. The key points are:

1) These are the names of qualifications. As often happens in Spanish, they refer to the person who holds the qualification ("maestro", "profesor"), whereas in English it is normal to refer to the qualification itself ("degree", "diploma", "certificate", or whatever).

2) These are NON-UNIVERSITY qualifications, so I don't think it's correct to call them degrees. They are awarded by Institutes of Physical Education. Argentine universities award higher qualifications, normally called "Licenciado en Educación Física" or something similar. These are degrees. Sometimes people who have obtained a MNEF and PNEF at an Institute go on to do a Licenciatura at a university. Here's an example:
http://www.alejandrokohan.com/staff/pablo-dolce.pdf

3) Maestro Nacional is a three-year course which (as the name implies) qualifies you to teach physical education at primary level (elementary, as you would call it in the US). It is awarded when you have complete the primer ciclo (3 years). Profesor Nacional is a four-year course, involving a further segundo ciclo (1 year) and entitles you to teach physical education at all school levels:

"1.5 Ciclos y duración de la carrera:
a) Primer ciclo: tres años
b) Segundo ciclo: un año
1.6 Títulos que ofrece la carrera:
a) Al aprobar el primer ciclo: Maestro Nacional de Educación Física
b) Al aprobar el segundo ciclo: Profesor Nacional de Educación Física
1.7 Habilitación de los títulos:
Maestro Nacional de Educación Física:
- Docente para el nivel primario
- Habilitante para el nivel medio
Profesor Nacional de Educación Física:
- Docente para todos los niveles."
http://www.danielpallarola.com.ar/archivos/Decreto_926_80.pd...

In some cases they are two years and three years respectively.

I would use the word "diploma", which would be standard for this kind of qualification in the UK and a number of other countries, and I think would work also in the US, by analogy with the Diploma in Nursing, for example. I would add "primary", or "elementary" for the US, after the "Maestro" qualification, and use the word "Higher" for the "Profesor", to show that it is not just an alternative curriculum but involves further study.