Despite these investments, yields per hectare haven't increased significantly in over four decades.

尽管有这些资助，但每公顷农田的产量在 40 多年来并没有显著增加。

Despite these investments, yields per hectare haven’t increased significantly in over four decades.

尽管有这些投资，但四十多年来每公顷的产量并没有显着增加。