The Spanish had an empire across Europe, and brought potatoes for their armies. Peasants along the way adopted the crop, which was less often pillaged by marauding armies than above-ground stores of grain. Across most of northern Europe, where open fields prevailed, potatoes were strictly confined to small garden plots because field agriculture was strictly governed by custom that prescribed seasonal rhythms for plowing, sowing, harvesting and grazing animals on fallow and stubble. This meant that potatoes were barred from large-scale cultivation because the rules allowed only grain to be planted in the open fields.<ref>William H. McNeill, "How the Potato Changed the World's History." ''Social Research'' 1999 66(1): 67-83. </ref> In France and Germany government officials and noble landowners promoted the rapid conversion of fallow land into potato fields after 1750. | The Spanish had an empire across Europe, and brought potatoes for their armies. Peasants along the way adopted the crop, which was less often pillaged by marauding armies than above-ground stores of grain. Across most of northern Europe, where open fields prevailed, potatoes were strictly confined to small garden plots because field agriculture was strictly governed by custom that prescribed seasonal rhythms for plowing, sowing, harvesting and grazing animals on fallow and stubble. This meant that potatoes were barred from large-scale cultivation because the rules allowed only grain to be planted in the open fields.<ref>William H. McNeill, "How the Potato Changed the World's History." ''Social Research'' 1999 66(1): 67-83. </ref> In France and Germany government officials and noble landowners promoted the rapid conversion of fallow land into potato fields after 1750. |