M. A. Haque
Department of Soil Science, Patuakhali Science and Technology University (PSTU), Dumki, Patuakhali-8600, Bangladesh.
Field experiments were conducted at Patuakhali Science and Technology University research farm during 2009 T. Aman season to investigate the effect of tidal submergence on potassium nutrition and yield of rice. The experiment included two levels of irrigation water source tidal water and ground water, and three levels of fertilizers- absolute control (no fertilizer), NP (K omission), and NPK (K addition). The rice varieties were BR23 (HYV) and Lalmota (traditional variety). A general increase in growth, yield and yield contributing parameters were found due to irrigation with tidal water. Tidal water contributed about 19% (BR23) and 11% (Lalmota) higher grain yield in Aman season 2009 compared to that grown with ground water. Potassium contents of rice grain and straw were always higher when plants are irrigated with tidal water. In general, tidal submergence increased K uptake of rice. The K uptake by BR23 under tidal water was about 4743 and 8 kg/ha more than those recorded with ground water irrigation under absolute control, K omission and K addition treatments, respectively whereas it was 31, 21, and 68 kg/ha, in Lalmota. The results indicated that whether fertilizers were applied or not plants absorb considerable amount of K from tidal water.
Potassium, Rice, Tidal submergence
Patuakhali Science and Technology University research farm
Risk Management in Agriculture
To know the effect of tidal submergence to potassium nutrition of rice.
Two similar field/experiments were conducted during Aman season of 2009 at Patuakhali Science and Technology University research farm. Each experiment was laid out in split plot design which included two factors; first, 'source of irrigation water' consisting two levels: tidal water and ground water, second factor, 'fertilizer' consisting three levels: absolute control (no fertilizer), NP (K omission), and NPK (K addition). Thus, six treatment combinations were used in the experiments. Each treatment was replicated three times. High yielding rice variety BR23 was used in one experiment and traditional variety Lalmota was used in another experiment. A highland was selected for the experiments so that natural tidal water cannot enter into the plot and amount of irrigation water could be control easily. Irrigation water requirement of this field was higher compared to the other medium high or low lands. The initial soil of the field experiments contained 0.09% total N, 12.6 ppm available phosphorus, 0.39 me/100g soil exchangeable potassium, 46.5 ppm available S, 1.72% organic matter and pH of 7.5. Thirty five days old seedlings were transplanted on 3rd September 2009 with the plant spacing of 20x20 cm. Three to four seedlings were transplanted in each hill. Fertilizer application was made with 80, 20 and 60 kg/ha of N, P and K, respectively. Phosphorus and K were applied during puddling and N was applied in two equal splits at 15 and 30 days after transplanting. Fertilizers were allocated in the plots according to the treatments. Weeding was done and pesticide was applied two times during urea fertilizer application. Tidal water was collected from a channel which was connected with Paira river and given to the respective plots using a low lift pump. Ground water receiving plots were irrigated with deep-tube-well water. About 2-3 cm water depth was maintained in each plot during the growth period so that each plant can absorb required amount of nutrients from irrigation water. Potassium content of tidal water and ground water were 3.79 and 2.27 ppm, respectively. Plants were harvested at maturity and subsequent measurement of plant height, tillers/hill, grains/panicle and grain and straw yields were done. Chemical analysis of grain and straw were done using standard methods. The data obtained in the experiments were statistically analyzed using MSTAT computer software program.
BANGLADESH JOURNAL OF AGRICULTURAL RESEARCH, Vol-37 (3), pp. 433-439, September 2012, ISSN 0258-7122.
Tidal submergence is an important source of K. It increases all the growth parameters along with yield of rice. It supplies considerable quantities of K, however, it can not meet the total K requirement of rice.