Hi, Rachel, welcome to the forum!
I had not heard of teff grass even though I am fairly familiar with Texas Native grasses so I looked it up.
Eragrostis tef, also known as teff, Williams lovegrass or annual bunch grass, is an annual grass, a species of lovegrass native to the Horn of Africa, notably to modern-day Ethiopia.
https://en.wikipedia.org/wiki/Teff
Teff is a multipurpose crop which has a high importance for the Ethiopian diet and culture. In Ethiopia, teff provides two-thirds of the daily protein intake. It is not only important for human nutrition, but also as fodder for livestock, or as building material
Are you growing it to process into flour or as animal fodder?
How is it competing with that johnson grass?