Adapted from Idaho's fourth grade agricultural education curriculum guide, this manual was created because there were insufficient resources available to Ohio students about the systems that provide human beings with food and fiber. Economically Ohio's largest industry, agriculture, serves as a basis for providing fourth-grade teachers with supplemental materials to use in the four curriculum areas typically taught in the fourth grade: language arts, science, mathematics, and social studies. The lesson plans are placed into the curriculum area by the major type of activity contained in that lesson. Each lesson is also assigned to some minor curriculum areas if they exist within the lesson plan. Five agricultural concepts are included: (1) history of Ohio agriculture; (2) production of food and fiber; (3) economics of Ohio agriculture; (4) conservation of natural resources; and (5) careers in agriculture. A matrix relates curriculum areas to the lesson plans that have major or minor relevance. There are five units in the guide: introduction; agribusiness; plants; animals; agriculture and natural resources; and information sources. The first four units include the following elements: (1) background (2) agriculture unit; (3) core, major; (4) core, minor; (5) related lesson plan; (6) remarks/notes; (7) resources; (8) premise; (9) objectives; (10) motivation; (11) vocabulary; (12) trivia; (13) suggested activities; (14) activity sheets; and (15) what has been learned. The information sources unit includes a 1990 directory of agriculture and an annotated list of 57 teaching materials available through Ohio sources. Copies of two color transparencies (soil ecosystem and soil profile) are included. (NLA)