to study the impact of nutrient management on the performance of aromatic fine rice in Boro season. The experiment comprised three varieties viz., BRRI dhan50, Basmati and BRRI dhan63; and seven nutrient managements viz., poultry manure @ 5 t ha-1 , recommended dose of chemical fertilizers (i.e. 250, 126, 120, 100 and 10 kg N-P-K-S-Zn, respectively ha-1), 25% less than recommended dose of chemical fertilizer + poultry manure @ 2.5 t ha-1 , 50% less than recommended dose of chemical fertilizer + poultry manure @ 5 t ha-1 , vermicompost @ 10 t ha-1 , 25% less than recommended dose of chemical fertilizer + vermicompost 5 t ha-1 , 50% less than recommended dose of chemical fertilizer + vermicompost @ 10 t ha-1. The experiment was laid out in a randomized complete block design with three replications. The results revealed that variety, nutrient management and their interaction exerted significant influence on yield components and yield of aromatic fine rice in Boro season. The highest grain yield (4.09 t ha-1), straw yield (6.20 t ha-1) and harvest index (39.37%) were obtained in BRRI dhan63 while the lowest grain yield (3.44 t ha-1) and harvest index (36.54%) were found in Basmati. In case of nutrient management, the highest grain yield (4.31 t ha-1) was recorded in recommended dose of chemical fertilizers (i.e. 250, 126, 120, 100 and 10 kg N-P-K-S-Zn, respectively ha-1) which was as good as 25% less than recommended dose of chemical fertilizer + vermicompost @ 5 t ha-1 and 25% less than recommended dose of chemical fertilizer + poultry manure @ 2.5 t ha-1 while the lowest one (2.74 t ha-1) was found in vermicompost @ 10 t ha-1. In case of interaction, the highest grain yield (5.30 t ha-1) was obtained in BRRI dhan63 along with 50% less than recommended dose of chemical fertilizer + vermicompost @ 10 t ha-1 while the highest straw yield (7.20 t ha-1) was produced in BRRI dhan63 fertilized with recommended dose of chemical fertilizers (i.e. 250, 126, 120, 100 and 10 kg N-P-K-S-Zn, respectively ha-1). Therefore, it can be concluded that BRRI dhan63 can be grown with 50% less than recommended dose of chemical fertilizer + vermicompost @10 t ha-1 in Boro season to obtain the highest grain yield.

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to study the effect of integrated fertilizer and weed management on the growth performance of aromatic Boro rice (cv. BRRI dhan50). The experiment comprised six fertilizer managements viz., control (no manures and no fertilizers), recommended dose of inorganic fertilizers (i.e. Urea, TSP, MoP, Gypsum, ZnSO4 @ 250, 120, 120, 100, 10 kg ha-1, respectively), 50% of recommended dose of inorganic fertilizers + cowdung @ 5 t ha-1, 75% of recommended dose of inorganic fertilizers + cowdung @ 5 t ha-1, 50% of recommended dose of inorganic fertilizers + poultry manure @ 2.5 t ha-1, and 75% of recommended dose of inorganic fertilizers +  poultry manure @ 2.5 t ha-1 and four weed managements viz., control (no weeding), pre-emergence herbicide, Panida 33 EC @ 2.5 l ha-1 + one hand weeding at 35 DAT, post-emergence herbicide, Granite 240 SC @ 93.70 ml ha-1 + one hand weeding at 35 DAT, pre-emergence herbicide, Panida 33 EC @ 2.5 l ha-1 + post-emergence herbicide, Granite 240 SC @ 93.70 ml ha-1. The experiment was laid out in a factorial randomized complete block design with three replications. Growth traits of aromatic Boro rice (cv. BRRI dhan50) were significantly influenced by integrated fertilizer and weed management. Plant height, number of tillers hill-1, total dry matter, leaf area index (LAI) and crop growth rate (CGR) gave their highest values in 75% of recommended dose of inorganic fertilizers and poultry manure @ 2.5 t ha-1 along with pre-emergence herbicide, Panida 33 EC @ 2.5 l ha-1 + post-emergence herbicide, Granite 240 SC @ 93.70 ml ha-1 while their corresponding lowest values were found in control. So it can be concluded that, the interaction of 75% of recommended dose of inorganic fertilizers and poultry manure @ 2.5 t ha-1 along with pre-emergence herbicide (Panida 33 EC @ 2.5 l ha-1) + post-emergence herbicide (Granite 240 SC @ 93.70 ml ha-1) appears as the promising combination in respect of growth performance of aromatic Boro rice (cv. BRRI dhan50).

An investigation was carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University to inspect the effect of vermicompost based nitrogen management and plant spacing on the yield performance of short duration transplant Aus rice (cv. Parija). The study comprised three spacing viz. 20 cm × 20 cm, 20 cm × 15 cm and 20 cm × 10 cm, and five nitrogen management viz. no nitrogen, 75 kg N ha-1, 55 kg N ha-1 + vermicompost @1.25 t ha-1, 35 kg N ha-1 + vermicompost @2.5 t ha-1 and vermicompost @5 t ha-1. The experiment was laid out in a Randomized Complete Block Design with three replications. At harvest, both the spacing of 20 cm × 20 cm and 20 cm × 15 cm produced the tallest plants, the highest number of total tillers hill-1 and effective tillers hill-1. The highest grain yield (3.59 t ha-1) was recorded in 20 cm × 15 cm spacing which was at par with the grain yield (3.52 t ha-1) in 20 cm × 10 cm spacing. The 20 cm × 10 cm spacing also produced the highest straw yield (4.88 t ha-1) and biological yield (8.40 t ha-1). The lowest grain, straw and biological yields were recorded at the wider spacing of 20 cm × 20 cm. In contrast, the highest grain yield (3.79 t ha-1), straw yield (4.99 t ha-1) and biological yield (8.79 t ha-1) were found in 75 kg N ha-1 which was as good as the yields of 55 kg N ha-1 N+ vermicompost @1.25 t ha-1. The highest number of total tillers hill-1 (14.11) and effective tillers hill-1 (12.67) were found in the interaction effect of 20 cm × 20 cm spacing with 75 kg N ha-1. The interaction between 20 cm × 15 cm and 55 kg N ha-1 N+ vermicompost @1.25 t ha-1 gave the highest grain yield (4.58 t ha-1), straw yield (5.71 t ha-1) and biological yield (10.29 t ha-1). The lowest grain yield (2.03 t ha-1), straw yield (3.49 t ha-1) and biological yield (5.52 t ha-1) were found in the interaction between 20 cm × 20 cm and no nitrogen. Therefore, usage of 20 cm × 15 cm spacing fertilized with 55 kg N ha-1 + vermicompost @1.25 t ha-1 appeared as the promising practice of transplant Aus rice cv. (Parija) cultivation.

to investigate the effect of spacing of planting on the yield performance of some aromatic rice varieties in Boro season. The experiment comprised three varieties viz. BRRI dhan50, Basmati and BRRI dhan63, six spacing of planting viz. 25 cm × 20 cm, 25 cm × 15 cm, 20 cm × 20 cm, 20 cm × 15 cm, 15 cm × 15 cm and 20 cm × 10 cm. The experiment was laid out in a randomized complete block design with three replications. The highest grain yield (4.01 t ha -1 ) and harvest index (47.38 %) were recorded in BRRI dhan50 followed by BRRI dhan63 while the lowest grain (3.44 t ha -1 ) and highest straw (5.11 t ha -1 ) yields were recorded in Basmati. Planting spacing 20 cm × 10 cm gave the highest grain (4.54 t ha -1 ) and straw (5.92 t ha -1 ) yields compared to other spacing. BRRI dhan50 along with 20 cm × 10 cm spacing produced the highest grain yield (5.08 t ha -1 ) while the highest straw yield (6.71 t ha -1 ) was recorded in Basmati at 20 cm × 10 cm plant spacing. Based on the present study it can be concluded that BRRI dhan50 along with 20 cm × 10 cm spacing of planting appears as the promising combination for higher grain yield in Boro season.

No abstract

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University during November 2016 to April 2017 to investigate the effect of nutrient management on the growth performance of some aromatic rice varieties in Boro season. The experiment was laid out in a randomized complete block design with three replications considering two factors viz. varieties and nutrient management. This experiment consisted of three varieties viz., BRRI dhan50, Basmati and BRRI dhan63, and seven nutrient managements viz., poultry manure 5 t ha-1, recommended dose of chemical fertilizers (i.e. 250, 126, 120, 100 and 10 kg N-P-K-S-Zn, respectively ha-1), 25% less than recommended dose of chemical fertilizer + poultry manure @ 2.5 t ha-1, 50% less than recommended dose of chemical fertilizer + poultry manure @ 5 t ha-1, vermicompost @ 10 t ha-1, 25% less than recommended dose of chemical fertilizer + vermicompost @ 5 t ha-1 and 50% less than recommended dose of chemical fertilizer + vermicompost @ 10 t ha-1. The results revealed that variety, nutrient management and their interaction exerted significant influence on growth characters of aromatic fine rice in Boro season. The highest plant height (55.14 cm, 66.14 cm) at 70 and 85 DAT, dry matter hill-1 (15.39 g) at 85 DAT and chlorophyll content (39.29) at 55 DAT was recorded from BRRI dhan63. While, Basmati produced the highest leaf area index (0.60) at 60 DAT and the highest number of total tillers hill-1 (11.52, 10.81, 9.619) was obtained from BRRI dhan50 at 55, 70, 85 DAT. In case of nutrient management practices, 25% less than recommended dose of chemical fertilizer + vermicompost 5 t ha-1 produced the highest plant height (45.22cm, 55.22cm, 65.67 cm) at 55, 70, 85 DAT, leaf area index (0.70) at 60 DAT and chlorophyll content (41.56) at 55 DAT, respectively. Again, from the interaction, it was observed that all the growth parameters were significantly influenced and increased with suitable variety along with proper nutrient management. Therefore, from this study, it can be decided that BRRI dhan63 fertilized along with 25% less than recommended dose of chemical fertilizer + vermicompost 5 t ha-1 might be the best possible combination for proper growth of plant.

An experiment was conducted to investigate the effect of standing water levels on methane gas emission and yield of transplanted Aman rice (cv. BRRI dhan51) during July to December 2015 at medium low-lying area of Mohangonj upazila under Netrokona district. The experiment comprised five standing water levels on surface paddy soil viz., 5 cm, 10 cm, 15 cm, 20 cm and 25 cm. Methane (CH4) gas emission, yield components and yield of transplanted Aman rice were significantly affected by standing water levels on surface paddy soil. CH4 emission was gradually increased with rising standing water levels and remained static condition at 20-25 cm water level.  The highest CH4 emission was observed at 20 cm standing water level and the lowest CH4 emission was recorded at 5 cm water level. The highest CH4   peak recorded at 85 days after transplanting (DAT). The highest CH4 flux (36.59 mg/m2/h) was observed in treatment 20 cm water level whereas the lowest CH4flux (21.17 mg/m2/h) was observed in 5 cm water level.  Finally, the CH4 emission dropped at 108 DAT. On and average, the CH4 emission rate during rice cultivation followed 20 cm > 25 cm> 15 cm > 10 cm > 5 cm water level. Soil Eh gradually decreased with progress of time and plant growth and at 85 DAT highly reduced condition developed in all treatments. The maximum reduced condition was observed (-238.67 mV) in treatment 20 cm water level and minimum one (- 214.667 mV) was found in 5 cm water level. The highest grain (5260 kg ha-1) and straw (6725.0 kg ha-1) yields were obtained at 10 cm standing water level while the lowest grain (4191.6 kg ha-1) and straw (5050.0 kg ha-1) yields were recorded in 5 cm and 15 cm water level, respectively. It may be concluded that 10 cm standing water level is beneficial for transplant Aman rice (cv. BRRI dhan51) cultivation in low lying area in respect of grain yield and environmental issues.