CẢI THIỆN CANH TÁC LÚA THÂM CANH BẰNG BIỆN PHÁP LUÂN CANH, ĐIỀU CHỈNH MẬT ĐỘ SẠ, LƯỢNG PHÂN ĐẠM VÀ QUẢN LÝ NƯỚC

The study on improvement of intensive rice production by crop rotation, regulation of plant population, nitrogen ferilizer rate and water management was conducted on the slightly acid sulfate soil in Giong Rieng district, Kien Giang province for 2 years. The result showed that row seeding and N applied adjustment by LCC increased the grain yield of 0.25-0.92 ton/ha. In the Spring-Summer (Early wet season - EWS), growing maize that got higher grain yield than growing rice of 1.73 ton/ha (38.4%). The grain yield of rice increased 0.63 ton/ha (16.3%) in the cropping system of C2 compared to that in the cropping system of C1 in the Summer-Autumn (Late wet season - LWS). Applied the controlled water management by AWD that saved the remarked amount of water input saving of 30.8%, 33.8% and 25.2% for dry season (DS), EWS and LWS, respectively. AWD helped to increase water productivity compared to that of conventional water management - continuous flooding (CF). AWD gave 1.45 to 2.81 kg rice m-3 water while CF gave only from 0.93 to 1.83 kg rice m-3 water. The C2 saved water input from 42.4 to 61.9% compared to the C1