From 1992 to 1995, experiments were conducted at the Asian Vegetable Research and Development Center (AVRDC) to test crop management technologies for their agronomic, ecological, and economical suitability to improve vegetable production in tropical lowlands. It was emphasized to develop practices for increasing production during the tropical rainy season when vegetable supply is most deficient. Technologies included: (1) permanent high beds, (2) the »Nmin-reduced method«, (3) the »integrated analysis of soil and plant nitrogen«, and (4) management of crop residues and green manure. Parameters studied during the 43-month crop sequence of 13 vegetable crops (6 species) and 7 aquatic field crops (3 species) were: yield, soil water, soil and plant nitrogen, root distribution, market supply and price, and production costs.