PERFORMANCE OF AEROBIC METHOD ON FIVE VARIETIES OF BORO RICE

Abstract

Aerobic system of rice production is an environment friendly technology that helps saving of 50-60% irrigation water in boro rice production. A field experiment was conducted at the Agronomy Field Laboratory of Hajee Mohammad Danesh Science and Technology University, Dinajpur during boro season to find out suitable rice varieties for aerobic rice cultivation. The treatments comprised of five varieties viz. BR16, BRRIdhan28, BRRIdhan29, BRRIdhan47 and BRRIdhan55 and two methods of planting (conventional transplanting method and aerobic system of planting) which were evaluated in randomized complete block design with four replications. Boro rice crop was fertilized with urea, triple super phosphate, muriate of potash, gypsum and zinc sulphate according to BRRI recommendation doses. Forty five days old rice seedlings were transplanted on 30 January, 2013. After sampling, the whole plot was harvested at maturity stage. Total cost of production, gross income and net return were also calculated. Results showed that method of planting exerted significant influence on plant height, number of total grains panicle’', number of filled grains panicle’, 1000-grain weight, grain yield, straw and biological yields while other characters remained unaffected. Higher grain yield (5.61 t ha’) was obtained from conventional method of transplanting and lower grain yield (5.30 t ha’) was found in aerobic method of planting. On the other hand, there were significant differences among the rice varieties. BRRIdhan29 gave the highest grain yield (6.53 t ha”) followed by BR16 (5.84 t ha’) and the lowest grain yield was obtained from BRRIdhan28 (4.69 t ha"). In terms of economic return, the rice yield was increased about 5.5% in conventional transplanting method over aerobic method. But irrigation water is a costly input. In Bangladesh, about 28% of the cost for production of boro rice goes for irrigation. The irrigation cost for boro rice was Tk.14,450 ha! while the additional income from boro rice was only Tk. 4,650 ha’. So, Tk. 9800 ha’! was saved when aerobic method was adopted. Therefore, the irrigation water from both underground and surface sources are becoming scarce in the country which is making the boro rice production at stake. Under this looming water crisis situation boro rice production could be sustained by using the technology that requires very less water like aerobic method.