TIAA-CREF KNEW WHY IT WANTED TO BUY THE farm. The $487 billion, New York–based retirement fund and financial services firm had taken a serious look at global farmland investment in the middle of the 2000s. It saw stable returns above inflation, uncorrelated with the rest of its portfolio — and the opportunity to own a hard asset whose value is driven by surging worldwide demand for food.

But first, it had some spadework to do. Now one of a handful of firms catering to the growing institutional interest in responsible farmland investing, TIAA-CREF started out by purchasing some U.S. farms in 2007. However, its directors only felt comfortable going farther afield, to places like Australia and Brazil, if they were to build their own teams....