Our study shows how farmers in the Mekong Delta, Viet Nam, have developed new cropping systems and management practices to overcome the constraints of their land. Decision trees for land evaluation at farm level, combining farmer and expert knowledge, were developed to support management decisions and to indicate possibilities to improve land suitability. Our study concentrates on 2 districts, Tan Thanh ( fresh water, deep flood, acid soils) and Hong Dan ( acid soils, shallow flood, salt surface water). We recommend double rice, yam, sugarcane, and Melaleuca cajiputi for Tan Thanh, and double rice, rice combined with shrimp, single shrimp or crab, sugarcane, bamboo, and Melaleuca for Hong Dan. We show the land-related constraints and how they can be lifted.