چکیده (انگلیسی):

The rice-shrimp crop rotation system in the coastal provinces of Mekong Delta (MD) is a special farming system and has become the cultivation practices for decades. Currently, seven provinces in the Mekong Delta applied rice-shrimp farming systems are Soc Trang, Tra Vinh, Bac Lieu, Ca Mau, Ben Tre, Kien Giang and Long An. In this farming system in the dry season when the saltwater intrusion into the field usually begins in February and lasts about 8 months, up to September yearly, farmers raising shrimps, crab and some fishes. After harvesting shrimps, farmers use raining and fresh water to make desalination the field and grow rice in the late August or early September. The study aim is to build the procedure for this kind of initial organic production following the international standards and to demonstrate the organic rice production model for farmers to practice. The methods apply in this research includes experiments on organic fertilizers, high quality rice varieties comparision and seed sowing methods through experiment split-plot design, randomised complete block design along with farmer survey. The initial results showed that in the rice-shrimp system, the sowing density can reduce as compared to recent farmer practice (80-100 kg/ha) with around 60-70 kg/ha. From the experimental results can encourage farmers to apply a row seeding method (using row seeder) with many advantages, and can save seed (seed density below 60 kg/ha). In case of broadcasting seed by hand the seed density use about 70kg/ha. For study on the suitable rice varieties, VTN 19 varieties gave highest yield (4.72 t/ha), followed by ST 5 (4.52 t/ha-check), then OM 4900 (4.37 t/ha); OM 6162 (4.19 t/ha); and OM 5451 (4.09 t/ha). On the effective modeling of farmers producing organic rice, the real profit in the year 2015 was 24,023,000 VND and planning profit in the year 2016, 2017 were 26,511,200 VND and 31,487,600 VND per ha respectively. The highest capital efficiency third year of organic production is 2.4; then the second year (2.0) and first-year (1.8). While in case of inorganic rice production, the capital efficiency is only 1.4. Rice product produced from this organic rice project has received international organic rice certificates from EU (Europe), USDA (United States) and JAS (Japan). With the initial good results this model can encourage to multiply larger areas in the MD.