Wang Zhen
Xu Guangqi wrote the "Complete Treatise on Agriculture", an outstanding agricultural treatise that followed in the tradition of those such as Wang Zhen (wrote the "Wang Zhen Nong Shu" of 1313 AD) and Jia Sixia (wrote the "Chi Min Yao Shu" of 535 AD). Like Wang Zhen, Xu lived in troubled times, and was devoted as a patriot to aiding the rural farmers of China. His main interests were in irrigation, fertilizers, famine relief, economic crops, and empirical observation with early notions of chemistry. It was an enormous written work, some 700,000 written Chinese characters, making it 7 times as large as the work of both Jia Sixia and Wang Zhen. Although its final draft was unfinished by Xu Guangqi by the time of his death in 1633, the famous Jiangnan scholar Chen Zilong assembled a group of scholars to edit the draft, publishing it in 1639.