Dr. K P Halder
Senior Scientific Officer
Farm Management Division,
BRRI, Gazipur-1701. Bangladesh.
N. Ahmed
SSO
Entomology Division
BRRI, Gazipur-1701. Bangladesh.
M. Hasan
SSO
Plant Physiology Division
BRRI, Gazipur-1701. Bangladesh.
S S Parul
SSO
Training Division
BRRI, Gazipur-1701. Bangladesh.
Spacing , N- Rate, Dibble rice, Rice yield
BRRI Regional station Farm, Sonagazi, Feni
Crop-Soil-Water Management
The experiment was conducted at the BRRI Regional station, Sonagazi Farm, Feni during asus season in 1995 .The experimental field was a medium high land with silty loam having pH 7.2, organic mater 1.72 % total N 0.075%, available P (Olsen) 13.4 ppm and exchangeable K 0.34 meg/100 g soil. The soil was highly saline in nature. The salinity status was different in respect of different stage of the crop i.e. vegetative, reproductive and maturity stage and, in soil depth. Soil salinity level were 10,5, 5.1 and 4.1 mmhos in 0-5, 5 to 10 and 10-15 cm soil depth, respectively at maturity stage and, at reproductive and maturity stage, the soil salinity level were 4, 9, 3.8, 2.5, 2.0 mmhos, respectively in aforementioned soil depth. The experiment was laid out in a split plot design with three replications. The four nitrogen rates of 0, 30, 60 and 90 kg ha-1 were applied in the main plots and the three spacing of 20 cm x 25 cm, 15 cm x 25 cm and 20 cm x 20 cm were considered as sub-plot treatments. The unit plot size was 4 mx4 m with a 25 cm levee between plots and 50 cm drains between the replications. The seed rate was 40 kg ha-1 and was sown in the holes of 2.0-2.5 inches depth in lines made by a wooden peg. Fertilizer was applied as basal @ 60-40-10 kg ha-1 of P2O5, K2O and S from TSP, MP and gypsum, respectively. Nitrogen was applied as urea in three equal splits as basal , top dressed at 20 and 40 days after sowing (DAS), respectively. Weeding and other intercultural operations were done as and when necessary. At maturity stage of the crop, data of yield components were taken from 1 m sq. sample area of each plot The harvesting area of the crop was 5 sq.m. located at 14% moisture content. The collected data were analyzed following the standard statistical procedure as per Gomez and Gomez (1984). The agronomic efficiency i.e. amount of rice in kg produced by kg-1 N application as calculated by the following formula:
Kg rice Kg-1 N = Kg rice in treated plot- kg rice in N zero plot/Kg N ha-1 applied
Rectum per taka investment was calculated from the cost of additional added urea and price of rice, where costs of all other inputs were considered same. The price of per kg urea and rice was considered at Tk. 5.00 and 6.00, respectively and return was calculated by the following formula:
Rectum Tk-1 investment = A - B/ C
Where, A= Price of rice in treated plot.
B= Price of rice in N zero plot
C= Cost of urea ha-1 applied.
Bangladesh J. Agril. Sci.29(1):15-18.(2002)
15000/- (Fifteen Thousand)
Journal