High potential arable land of SA is estimated to  Blank 1. Fill in the blank, read surrounding text.

It seems that there is a specific context related to the estimation of high potential arable land in South Africa (SA) that is required to accurately fill in the blank. Without additional surrounding text or context, it is challenging to determine the exact figure or description needed for "Blank 1."

To accurately fill in the blank, I recommend looking for key figures, statistics, or descriptors in the surrounding passages that can provide insight into what is meant by "high potential arable land." This could include data about the total hectares, specific regions known for agricultural productivity, or qualitative assessments of land efficiency.

If you can provide more context or text surrounding "Blank 1," I would be happy to help in providing a more precise answer!