But arable land is mostly a function of rainfall and flatness.
You can turn almost any flat land into arable land given enough effort.
Terraced farming cannot be mechanised economically because you need very small combines that need to be transported up or down and building the terrace with excavators etc disrupts the soil which means you have to build it up which means hardly any productivity in the first decade. You got a huge equipment, logistics and construction problem which requires massive amounts of upfront capital for basically no cash flow during the most important years. We would need huge advances in agricultural robotics for this to be cost effective.
You can turn almost any flat land into arable land given enough effort.
Terraced farming cannot be mechanised economically because you need very small combines that need to be transported up or down and building the terrace with excavators etc disrupts the soil which means you have to build it up which means hardly any productivity in the first decade. You got a huge equipment, logistics and construction problem which requires massive amounts of upfront capital for basically no cash flow during the most important years. We would need huge advances in agricultural robotics for this to be cost effective.