Complex sentence: His interdisciplinary research interests encompass a broad area of energy, environmental, food, population, economic, historical and public policy studies, and he had also applied these approaches to energy, food and environmental affairs of China.
Split into simpler sentences: His interdisciplinary research interests encompass a broad area of energy, environmental, food, population, economic, historical and public policy studies. Smil applied these approaches to energy, food and environmental affairs of China.