ANALYSING ECONOMIC EFFICIENCY IN THE CROP ROTATION OF SHRIMP MONOCULTURE AND POLYCULTURE MODELS AT QUANG CONG COMMUNE, QUANG DIEN DISTRICT, THUA THIEN HUE PROVINCE

Abstract

Aquaculture activities in Quang Cong Commune, Quang Dien District have considerably impacted on the living of local people as well as the sustainable development of Tam Giang - Cau Hai Lagoon ecosystem. On surveying 36 aquaculture households in the high tide area with one semi-intensive shrimp crop and one poly-culture crop model, the obtained result shows that the average profit of poly-culture is 37.15 million VND/0.36 ha, i.e.1.95 times higher than shrimp monoculture with 19.1 million VND/0.36 ha. This translates the profit-to-cost ratio of poly-culture season and mono-culture season is 0.61 and 0.22 times, respectively. The main reason is that feed cost in poly-culture crop is only about 56% of that for mono-culture crop because the fish can eat the leftover food of shrimp, natural feed sources and crab can eat small crustaceans in ponds and dead shrimps, thus helping reduce feed cost and improve the water quality in ponds.