Sentence:  ... the larger plantations implemented different crop choices, surveillance strategies, and labor management practices than did <WSD>smallholdings</WSD>. 
Meaning of the word marked with <WSD> tags:  A small plantation or land with a small number of slaves (generally 19 or less). Contrasted with "middling plantation" (20-49 slaves) and "large plantation" (50+ and owned by planters).