Spain and portugal differences

The biggest geographic difference between Portugal and Spain is the size; Spain is around five times larger than Portugal. Both countries have Mediterranean climates, meaning they are generally temperate, with warm summers and mild winters, and the languages.

the answer is "by providing data about careers and annual mean wages"

crop rotation kepy different plants in the soil instead of once constintly. when switching out plants you have different nutrients being absorbed at different speeds and different roots growing differently therfore the spoil and water flow have to adapt and carry fresh nutrients to carry the constant changes that were going on in the soil.