machines and technology / garden tool / food production / farm tools / harvested energy / green technology / farm tool / steel plow / Online Resource / lever modern technology / metal blade / Chemical fertilizers / chemical / human energy / method chemicals / animal product / food / energy / /
Organization
Oklahoma State Department of Education / Oklahoma Department of Agriculture / Oklahoma Cooperative Extension Service / USDA Economic Research Service / /
Person
Jan Romero / Gretchen Will / Fred Hoeme / Extra Reading Connor / Pieter Brueghel / Lee Sullivan / Heather Collins / Winslow Homer / Sherley Anna / John Froelich / Barbara / Mary Azarian / /