Super Granule Research Articles

Effect of urea super granule application on physiological and yield attributes of rice

Effect of urea super granule application on physiological and yield attributes of rice

COMPARATIVE STUDY OF USG AND NPK BRIQUETTE ON THE PERFORMANCE OF JHUM RICE

Two experiments were conducted at Ramery para, Bandarban sadar, Bandarban, Bangladesh hill district in Chittagong under the AEZ (Agro Ecological Zone) 29 (Northern and Eastern Hills Tract) during March 2017 to November 2017 to study of USG and NPK briquette on the performance of Jhum rice. The experiment was conducted in two field and designed on Randomized Completely Block Design (RCBD). The treatments consisted of 7(seven) levels of USG (Urea Super Granule) and NPK briquette i.e. T1: Control, T2: 100% USG and PK (RFD) (267.5 kg ha-1), T3: 80% USG and PK (RFD) (214.1 kg ha-1), T4: 80% USG and PK (RFD) (320.8 kg ha-1), T5 :100%NPK briquette (267.5 kg ha-1), T6: 80% NPK briquette (214.1 kg ha-1), T7: 120% NPK briquette (320.8 kg ha-1). The growth and yield of Jhum rice were significantly influenced by different levels of USG and NPK briquette. The highest plant height of jhum rice (139.23 cm), effective tillers hill-1 (16.60), panicle length (30.23 cm), highest number of filled grain panicle-1 (245.23), 1000 grain weight (28.0 gm), straw yield (4.15 t/ha) and grain yield (3.56 t/ha) were found from T5 treatment receiving 100%NPK briquette (267.5 kg ha-1) and for all cases lowest results were found in T1 treatment receiving no fertilizer (control).

Effects of nitrogenous fertilizers on rice yield under continuous flooding and alternate wetting and drying conditions

In rice cultivation, water and nitrogen saving strategies are becoming more crucial in order to identify efficient and useful crop production and management approaches. A study was conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh to examine the combined effects of irrigation method and nitrogen fertilizer on yield contributing traits and yield of rice cv. BRRI dhan29. The experiment was set up in a split-plot based on a randomized complete block design with 3 replications and 14 treatment combinations. Two irrigation methods such as continuous flooding (CF) and alternate wetting and drying (AWD) were the main factor while nitrogen fertilizers including prilled urea (PU) and urea super granule (USG) were the sub-factor. The treatment T6 (USG at 7 DAT) generated the highest plant height (cm), no. of effective tillers hill-1, panicle length (cm), no. of grains panicle-1, grain yield and biological yield during AWD condition. In terms of grain yield, the treatment combinations AWD + T6 and CF + T7 were statistically equal. In comparison to control, all AWD + USG and CF + PU treatment combinations increased straw yield and harvest index. Under both AWD and CF conditions, USG increased more grain and straw yields compared to PU. So, farmers may be advised to apply USG (216 kg ha-1) at 7 DAT under AWD conditions in order to improve rice yield and ensure food security.

Effect of nitrogen management and seedling raising methods on the productivity of Aus rice under tidal ecosystem of Bangladesh

The low productivity of Aus rice in the tidal ecosystem of Bangladesh is mainly due to the difficulties in nitrogen (N) management under high tidal water along with unavailability of irrigation water during the onset of rice cultivation. Our present study demonstrated how the productivity of Aus rice could be improved using appropriate seedling raising methods and N management practices. The study was laid out in split plot design consisting two factors viz., seedling raising methods (wet seed bed and dry seed bed) and N management practices (six N treatments) in three replications. Results indicated that both the seedling raising methods and N management practices had significant effect on all the yield contributing characters of transplanted Aus rice under tidal condition. Specifically, the combination of seedlings raised in wet seed bed and fertilized with urea super granule (USG) at 10 days after transplanting (DAT) i.e., N3W showed the best values for plant height (110.33cm), number of effective tillers hill-1 (14.60), days required 50% flowering (53.00 DAT), days to maturity (84.33 DAT), panicle length (23.37 cm), number of filled grain panicle-1 (88.13), 1000-grain weight (43.17 g), grain yield (4.62 tha-1), straw yield (6.07 tha-1), biological yield (10.67 tha-1), and harvest index (43.17%). However, in considering the productivity/ grain yield, besides N3W, the whole urea application at land preparation along with wet seed bed (N1W) and USG application along with dry seed bed (N3D) also produced statistically similar results (p<0.01) and thus all these three combinations may be practiced for improving productivity and ensuring horizontal expansion of Aus rice in the tidal ecosystem of Bangladesh.

Effect of Different Forms and Levels of Urea Fertilizer on Rice (Oryza sativa L) and Mineral Nitrogen Status in Soil

Field experiment was conducted to determine the effect of prilled urea (PU) and urea super granule (USG) with their different nitrogen levels (N1 : 70, N2 : 100 and N3 : 130% of the recommended dose) on rice and NH4+-N/NO3- -N in post-harvest soil. Experiment was laid out in a randomized completely block design with three replications at Bangladesh Institute of Nuclear Agriculture (BINA) Farm, Mymensingh, Bangladesh during 2015-16. Higher yield attributing characters (plant height, effective tiller panicle-1, panicle length were achieved from USG × N2 treatment. USG, N2 (100% N) and USG × N2 produced the highest grain (3.60, 3.64, 3.78 t ha-1) and straw yield (3.55, 3.45, 3.70 t ha-1) respectively. Though USG × N3 treatment produced the highest effective tiller, panicle length and unfilled grain but USG × N2 treatment produced maximum grain yield of rice due to higher filled grain. In respect of mineral nitrogen, NH4+-N was decreased with the increase in soil depth but opposite result was found in NO3- -N in soil. Deep placement of USG fertilizer released NH4+-N slowly and steadily compared to prilled urea in soil. As a result, one time fertilizer application of USG is better than three times broadcast application of PU in terms of crop yield, nitrogen status in different depth of soil and labour cost. Future research needs to develop the effective USG fertilizer applicator for deep placement in soil during crop production.

Performance of Prilled Urea and Urea Super Granule by Applicators on Yield and Nitrogen Use Efficiency in Boro Rice

A field experiment was conducted on validation of prilled urea (PU) and urea super granule (USG) applied by applicators on yield and nitrogen use efficiency during Boro 2014 season at Bangladesh Rice Research Institute (BRRI) farm, Gazipur (AEZ 28). Six treatment combinations of different N doses and methods of N application were tested to compare urea-N application by PU and USG applicator for rice yield, N uptake and N use efficiency over urea broadcasting. Application of N as PU or USG through applicator has same effect on grain yield, N uptake and N use efficiency compared with urea broadcasting. Statistically similar grain yield were observed with N application as PU or USG @ 78 kg N ha-1 by applicator which was comparable with urea broadcasting @ 135 kg N ha-1. The N concentration and uptake in both panicle initiation (PI) and maturity stage were higher in USG deep placement than PU deep placement by applicators but the difference was not significant. Although agronomic use efficiency (AUE) of N was slightly higher in PU than USG applied by applicators but the recovery efficiency (RE) of N was higher in USG than PU.
 Bangladesh Rice j. 2018, 22(2): 63-69

Study of nitrogen use efficiency and yield of rice influenced by deep placement of nitrogen fertilizers

Continuous increase of nitrogen fertilizer use adversely affecting the soil health as well as the environment. It necessitates the systematic study of the impact of nitrogen (N) fertilizer use-reduction on crop yield. In this article, the effects of deep placement of nitrogen fertilizers on nitrogen use efficiency (NUE) and yield of rice variety “BRRI dhan46” were investigated and compared for three N formulations: urea super granule (USG), NPK briquettes and prilled urea (PU). The experiment was conducted in randomized complete block design (RCBD) with eight N treatments replicated three times. The treatments were applied by varying doses (0, 52, 78 and 104 kg ha-1) of nitrogen fertilizers in a known identical soil and weather condition. Applications of PU, USG and NPK briquettes exhibited significant differences on yield attributes of rice. Results revealed maximum grain yield of 6.391 t ha-1 (54% increases over control) for the dose USG 104 kg ha-1 which is statistically similar to the dose USG 78 kg ha-1 and NPK briquettes 104 kg ha-1. The deep placement of USG and NPK briquettes enhanced both the recovery of applied N and N use efficiency compared to broadcast application of prilled urea. However, USG 78 kg ha-1 showed maximum apparent N recovery, N use efficiency, gross margin and marginal benefit-cost ratio. Thus, an application of 78 kg ha-1 USG can be recommended for profitable cultivation of rice variety BRRI dhan46.
 SAARC J. Agri., 17(1): 93-103 (2019)

Agronomic, economic, and environmental performance of nitrogen rates and source in Bangladesh’s coastal rice agroecosystems

Farmers in low-elevation coastal zones in South Asia face numerous food security and environmental sustainability challenges. This study evaluated the effects of nitrogen (N) rate and source on the agronomic, economic, and environmental performance of transplanted and rainfed ‘aman’ (monsoon-season) rice in Bangladesh’s non-saline coastal areas. Fifty-one farmers participated in trials distributed across two landscape positions described as ‘highlands’ (on which field water inundation depth typically remains <30 cm) and ‘medium-highlands’ (inundation depths 30–90 cm) planted singly with varieties appropriate to each position (BRRI dhan 39 for highlands and the traditional variety Bhushiara for medium-highlands). Researcher designed but farmer-managed dispersed plots were located across three district sub-units (Barisal Sadar, Hizla, Mehendigonj) and compared N source (broadcast prilled urea or deep-placed urea super granules (USG)) at four N rates. Rice grown on medium-highlands did not respond to increasing N rates beyond 28 kg N ha−1, indicating that little fertilization is required to maintain yields and profitability while limiting environmental externalities. In highland locations, clear trade-offs between agronomic and environmental goals were observed. To increase yields and profits for BRRI dhan 39, 50 or 75 kg N ha−1 was often needed, although these rates were associated with declining energy and increasing greenhouse gas (GHG) efficiencies. Compared to prilled urea, USG had no impact on yield, economic, energy and GHG efficiencies in medium-highland locations. USG conversely led to 4.2–5.8% yield improvements at higher N rates on highlands, while also increasing energy efficiency. Given the observed yield, agronomic and economic benefit of USG, our preliminary results that farmers can consider use of USG at 50 kg N ha−1 to produce yields equivalent to 75 kg N ha−1 of prilled urea in highland landscapes, while also reducing environmental externalities. These results suggest that when assessing sustainable intensification (SI) strategies for rice in South Asia’s coastal zones, N requirements should be evaluated within specific production contexts (e.g. cultivar type within landscape position) to identify options for increasing yields without negatively influencing environmental and economic indicators. Similar studies in other parts of coastal South Asia could help policy-makers prioritize investments in agriculture with the aim of improving rice productivity while also considering income generation and environmental outcomes.

Nitrogen management in rice

Nitrogen is the one of most limiting nutrient for rice production, and in India rice cultivation alone accounts approximately 37% of the total fertilizer-N consumption in the year 1917-18. However, 60-70% of applied N is lost from the rice ecosystem system in the form of reactive N species such as ammonia (NH3), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2) and nitrate (NO3) through various processes. Hence enhancing N use efficiency through improved N management is of greater importance for ensuring food security and environmental sustainability. The decisions on optimum level, time, form and method of N application are crucial to an efficient N management strategy. Earlier studies suggested blanket fertilizer recommendations for different rice ecosystems and soil test based fertilizer applications. Subsequently, innovative methods of N application including deep placement of urea super granule in reduced zone, subsurface incorporation of urea through farmer friendly methods were also recommended Recently several advancements have been made in N management practices for rice crop such as site specific N management, real time N management using leaf colour chart (LCC) and customised LCC, enhanced efficiency N fertilizers (EENF) using N transformation regulators and GIS and remote sensing (RS) - based N application technologies. The objective of this paper is to comprehensively discuss about the established and emerging N management options for improving yield, N use efficiency and environmental sustainability of rice.

Nitrogen management in rice

Nitrogen is the one of most limiting nutrient for rice production, and in India rice cultivation alone accounts approximately 37% of the total fertilizer-N consumption in the year 1917-18. However, 60-70% of applied N is lost from the rice ecosystem system in the form of reactive N species such as ammonia (NH3), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2) and nitrate (NO3) through various processes. Hence enhancing N use efficiency through improved N management is of greater importance for ensuring food security and environmental sustainability. The decisions on optimum level, time, form and method of N application are crucial to an efficient N management strategy. Earlier studies suggested blanket fertilizer recommendations for different rice ecosystems and soil test based fertilizer applications. Subsequently, innovative methods of N application including deep placement of urea super granule in reduced zone, subsurface incorporation of urea through farmer friendly methods were also recommended Recently several advancements have been made in N management practices for rice crop such as site specific N management, real time N management using leaf colour chart (LCC) and customised LCC, enhanced efficiency N fertilizers (EENF) using N transformation regulators and GIS and remote sensing (RS) - based N application technologies. The objective of this paper is to comprehensively discuss about the established and emerging N management options for improving yield, N use efficiency and environmental sustainability of rice.

Nitrogen use efficiency and yield of BRRI dhan49 as influenced by different forms of N fertilizers under AWD condition

An experiment was conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during Aman season of 2016 to evaluate the effects of deep placement of N fertilizers in the form of urea super granule (USG) and NPK briquettes in comparison with prilled urea (PU) on nitrogen use efficiency and yield of BRRI dhan49. The soil was silt loam in texture having pH 6.27, organic matter content 1.95% and total N 0.136%. The experiment was laid out in a Randomized Complete Block Design (RCBD) with eight treatments and three replications. The treatments include T1 (Control), T2 (PU, 104 kg N ha-1), T3 (USG, 104 kg N ha- 1), T4 (USG 78 kg N ha-1), T5 (USG, 52 kg N ha-1), T6 (NPK briquettes, 104 kg N ha-1), T7 (NPK briquettes, 78 kg N ha-1) and T8 (NPK briquettes, 52 kg N ha-1). All the treatments except T6, T7 and T8 received 16 kg P and 42 kg K ha-1 from TSP and MoP, respectively. In T6, T7 and T8 treatments, P and K were supplied from NPK briquettes. The PU was applied in three equal splits. The USG and NPK briquettes were deep placed 10 DAT and the briquettes were placed at 8-10 cm depth between four hills at alternate rows. Application of PU, USG and NPK briquette under alternate wetting and drying (AWD) condition exerted significant influence on yield attributes as well as grain and straw yields of BRRI dhan49. The maximum grain yield of 6311 kg ha-1 (100% increases over control) and straw yield of 6956 kg ha-1 was recorded in T3 (USG, 104 kg N ha-1). The second highest grain yield of 5865 kg ha-1 produced by T2 (PU, 104 kg N ha-1) was statistically similar with T4 (USG 78 kg N ha-1) and T6 (NPK briquettes, 104 kg N ha-1). The lowest grain yield (3155 kg ha-1) and straw yield (3908 kg ha-1) were recorded in T1 (Control). The deep placement of USG and NPK briquettes enhanced both the recovery of applied N and N use efficiency in comparison with broadcast application of prilled urea. The T5 (USG, 52 kg N ha-1) showed maximum apparent N recovery, and N use efficiency. Next to T5, the T4 depicted the position in respect of N recovery and N use efficiency. So the application of 78 kg N ha-1 in the form of USG can be recommended for the production of BRRI dhan49.&#x0D; Res. Agric., Livest. Fish.6(1): 27-33, April 2019

Economics of Boro Rice Production in Rangpur District of Bangladesh: Comparative Assessment of Urea Super Granule and Traditional Urea Application

The study was examined the profitability of Boro rice production using Urea Super Granule (USG) and traditional urea in Rangpur district of Bangladesh. 60 farmers were selected randomly for the present study. The cultivation of Boro rice was profitable from the viewpoint of the farmers. Per hectare net return for USG user and traditional urea user was Tk. 40264.4 and Tk. 26740.2, respectively. Benefit cost ratio for USG user and traditional urea user was estimated at 1.5 and 1.3, respectively. BCR was higher for USG user because they were efficient producer. Power tiller cost, seed/seedling cost, TSP cost, MoP cost, cowdung cost and irrigation cost; and human labor cost, seed/seedling cost, urea cost, MoP cost, cowdung cost and irrigation cost had significant impact on gross return from Boro rice production for USG and traditional urea user, respectively. Age of farmer, price of USG, soil nutrient availability and extension contact had significant impact on farmers’ preference for using USG in Boro rice production. The price of fertilizer should be regulated strictly by the government and extension programs should be arranged in order to motivate farmers for adopting USG use in Boro rice production.

Response of broccoli to USG and prilled urea in shallow red-brown terrace soil under Madhupur tract

A field experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during the period from 2012-13 to verify the effectiveness of urea super granule (USG) and prilled urea (PU) on the yield and quality of broccoli, to assess the comparative performance of USG and PU on nutrient uptake and nitrogen use efficiency and to evaluate the effect of USG and PU on post-harvest nutrient status in Shallow Red-Brown Terrace Soil of Madhupur Tract (AEZ-28). The experiment was designed in a randomized complete block with three replications having 5 treatments as T1: Control, T2: USG-N140, T3: USG-N160, T4: USG-N180 and T5: PU-N180. Result showed that USG performed better than PU. The comparative performance of USG in relation to yield, head quality (ascorbic acid, β-carotene and chlorophyll content), SPAD value, nutrient (NPKS) uptake and N use efficiency was found higher as compared to PU. USG treated broccoli plants gave significantly higher yield where the highest yield (13.49 ton ha-1) was recorded with USG-N160 kg ha-1. Moreover, USG showed higher β-carotene and chlorophyll content over PU and those were increased with increasing levels of N. However, ascorbic acid content was slightly decreased with increasing rate of N fertilizer. Nitrogen, phosphorus and potassium uptake increased with increasing N rate upto USGN180 but sulphur uptake was increased upto USG-N160. Nitrogen use efficiency was higher in USG treated plots than that of PU having the highest value of 111.71% with USG-N160 kg ha-1. Post-harvest soil nutrient status was not significantly influenced by the treatments although it was slightly higher in USG as compared to PU. Considering all, USG @ 160 kg N ha-1 (USG-N160) with other recommended fertilizers (@ 53 kg P, 83 kg K, 20 kg S, 2.0 kg Zn, 1 kg B and 0.8 kg Mo ha-1) could be the best USG based fertilizer dose for quality broccoli production in Shallow Red-Brown Terrace Soil of Madhupur Tract.Bangladesh J. Agril. Res. 43(4): 557-574, December 2018

Economics of Boro Rice Production in Rangpur District of Bangladesh: Comparative Assessment of Urea Super Granule and Traditional Urea Application

Economics of Boro Rice Production in Rangpur District of Bangladesh: Comparative Assessment of Urea Super Granule and Traditional Urea Application

Response of Some Landrace Rice (&lt;i&gt;Oryza sativa&lt;/i&gt; L.) Cultivars to Applied Nitrogen in Lowland Ecosystem

An experiment was conducted to determine the effects of nitrogen (N) fertilization on growth and yield of some landrace rice (Oryza sativa L.) cultivars in lowland ecosystem. Three popular landrace rice cultivars: Rajashail, Kutiagni and Sadamota were treated with five times of N application viz. (i) two split applications of prilled urea (PU) at 10 days after transplanting (DAT) and before panicle initiation (PI) stage, (ii) deep placement of urea super granule (DPUSG) at 10 DAT, (iii) DPUSG before PI stage, (iv) PU application before PI stage and (v) control. The results showed that the landrace rice cultivar Kutiagni had the highest number of tillers under PU, while Rajashail gave the highest number of tillers under DPUSG applied before PI stage. Further, Kutiagni produced higher amount of dry matter under two splits of PU, while Rajashail produced higher amount of dry matter under DPUSG applied before PI stage. However, application of PU before PI stage significantly increased leaf area index in all the three landraces. The varieties responded to applied N and produced the highest yield in Kutiagni. The DPUSG at 10 DAT increased straw yield but failed to increase grain yield even over control. The DPUSG before PI stage significantly increased rice yield and economic return. The yield of rice in DPUSG applied before PI stage was comparable to two splits of PU and top dressing of PU before PI stage. Compared to control (2.93 t ha-1), yield increase was 26% in Kutiagni (3.70 t ha-1) under DPUSG before PI stage. These results suggest that Kutiagni was more responsive to added N and this cultivar could be cultivated with DPUSG at PI stage.The Agriculturists 2018; 16(1) 01-12

Enhancing Rice Productivity through integration of Stress Tolerant Rice Varieties and Improved Nutrient Management Practices in Saline Areas of Bangladesh

The study was conducted in two locations of coastal districts Patuakhali and Satkhira during 2012 and 2013 T. Aman season. Stress tolerant rice varieties along with nitrogen application using prilled urea (PU), leaf color chart (LCC), urea super granule (USG), and rice crop manager (RCM) software based nitrogen (N) dose were examined. The objectives of the study were to identify the response of saline tolerant varieties to N fertilization on grain yield and profitability. Among the tested varieties, grain yield of BRRI dhan40, BRRI dhan41 and BRRI dhan54 were higher compared to BRRI dhan52 and BRRI dhan53 irrespective of location. There were no significant difference among the better performed varieties. Interaction effect of yield was significant in 2013 at Patuakhali but insignificant in both the locations in 2012. During 2013 in Patuakhali, the interaction effect of BRRI dhan40 × USG and BRRI dhan41 × USG produced higher grain yield and total N uptake. In Satkhira BRRI dhan54 and BRRI dhan40 performed better and produced higher grain yield and N uptake. Among the N application treatments USG application was the best compared to either LCC or RCM. The combination of BRRI dhan54×USG and BRRI dhan41×USG had more economic gains in both 2012 and 2013 in Patuakhali. The combination of BRRI dhan52×USG and BRRI dhan41×LCC appeared as themost profitable in Satkhira during 2013. Integration of saline tolerant varieties along with USG application could improve the yield of saline tolerant rice in saline environmentBangladesh Rice j. 2017, 21(1): 77-89

Effect of urea super granule and prilled urea on the growth and yield of broccoli

A field experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during the period from 2012-13 to verify the effectiveness of urea super granule (USG) and prilled urea (PU)on growth, yield and yield attributes of broccoli in Shallow Red-Brown Terrace Soil under Madhupur Tract (AEZ-28). The experiment was laid out in a Randomized Complete Block Design with three replications having 5 treatments constituted with different levels of USG and PU as- T1: Control, T2: USG-N140 (140 kg N as USG), T3: USG-N160 (160 kg N as USG), T4: USG-N180 (180 kg N as USG), T5: PU-N180 (180 kg N as PU). Performance of USG was better than PU and the treatment USG-N160 gave the highest yield (13.49 ton ha-1) which was followed by USG-N180 (12.43 ton ha-1) and PU-N180(12.05 ton ha-1) having significant difference among these. Higher but statistically identical number of lateral head 5.103 and 5.38 was produced by USG-N160 and USG-N180 treatments, respectively in comparison with PU-N180 (5.04). But higher lateral head yields (6.05 and 5.03 ton ha-1) were found in USG-N180 treatments followed by PU-N180. All the yield contributing characters and the economic profitability were favorably correlated with these high yield performing treatments with the highest MRR (3336.67%) obtained from USG-N160 which indicated that USG @ 160 kg N ha-1 (USG-N160) is the most economically viable N dose in terms of yield and economics for broccoli production. Therefore, USG @ 160 kg N ha-1 (USG-N160) with other recommended fertilizer could be suggested as USG based fertilizer recommendation for better broccoli production in terms of yield and economics in Silty Clay Loam Soil of Madhupur Tract.Bangladesh J. Agril. Res. 43(1): 53-69, March 2018

Effect of Different Levels of Urea Super Granule and Prilled Urea on the Crop Quality, Nutrient Uptake and Soil Nutrient Status of Broccoli

A field experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during the period 2010-2011 to assess the effect of urea super granule (USG) and prilled urea (PU) on the quality attributes (Compactness coefficient, Vitamin C, β-carotene and chlorophyll contents) of broccoli, to assess the comparative performance of USG and PU on nutrient uptake and uptake efficiency of broccoli plant, to assess the effect of different forms and levels of urea N on the post harvest soil nutrient status of broccoli field and to select the better doses of USG and PU for quality broccoli production in Shallow Red-Brown Terrace Soil under Madhupur Tract (AEZ-28). The experiment was laid out in a randomized complete block design with three replications having 17 treatments constituted with different levels of urea super granule (USG) and prilled urea (PU) as- T1: N-control, T2: PU-N80, T3: PU-N100, T4: PU-N120, T5: PU-N140, T6: PU-N160, T7: PU-N180, T8: PU-N200, T9: PU-N220, T10: USG-N80, T11: USG-N100, T12: USG-N120, T13: USG-N140, T14: USG-N160, T15: USG-N180, T16: USG-N200, T17 and USG-N220 kg ha-1. Results revealed that the comparative performance of USG in relation to head quality (compactness coefficient, ascorbic acid, β-carotene and chlorophyll content), nutrient (NPKS) uptake and N uptake efficiency was found better as compared to PU. The compactness coefficient, β-carotene and chlorophyll contents were increased with increasing rate of N as well as USG and PU, but ascorbic acid content was slightly decreased with increasing rate of USG and PU. The maximum compactness coefficient (18.61) was found from the treatment USG-N180 that was followed by USG-N160 (18.24) and the highest β-carotene content (0.401 mg/100gFW) was found from USG-N160 followed by PU-N180 (0.40 mg/100gFW). Similarly the highest chlorophyll-a content (0.818 mg/100gFW) was found from USG-N180 followed by USG-N160 (0.814 mg/100gFW) and the highest chlorophyll-b content (1.141mg/100g FW) was recorded from USG-N180. The higher nutrient uptake and N uptake efficiency (108.531%) was obtained from USG treated plots over that of the PU. But N uptake efficiency was decreased with increasing rates of N fertilizer. But post harvest soil nitrogen status did not show any systematic trend although it was found higher in USG over PU. Similarly no remarkable changes were observed in post harvest soil P, K, S and B status for the crop. However, USG @ 160 kg N ha-1 (USG-N160) followed by USG-N140 and PU @ 180 kg N ha-1 (PU-N180) with other recommended doses of fertilizer could be suggested as USG and PU based fertilizer recommendation for a good quality broccoli production in terms of yield and quality in Silty Clay Loam Soil of Madhupur Tract.The Agriculturists 2017; 15(2) 24-39

Efficacy of Deep Placement of Nitrogen Fertilizers on N Use Efficiency and Yield of Boro Rice (cv. BRRI Dhan29)

The efficiency of nitrogen (N) fertilizers in rice culture is low due to their losses in different ways. An experiment was, therefore, conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during boro season of 2016 to evaluate the effect of deep placement of N fertilizers on N use efficiency and yield of BRRI dhan29 under alternate wetting and drying (AWD) condition. The soil was silt loam in texture having pH 6.07, organic matter content 1.10%, total N 0.055%, available P 3.6 ppm, exchangeable K 0.22 me% and available S 11.76 ppm. The experiment was laid out in a randomized complete block design with three replications. There were eight treatment combinations including T1 (Control), T2 (PU, 130 kg N/ha), T3 (USG, 130 kg N/ha), T4 (USG, 104 kg N/ha), T5 (USG, 78 kg N/ha), T6 (NPK briquette, 129 kg N/ha) and T7 (NPK briquette, 102 kg/ha) and T8 (NPK briquette, 78 kg N/ha). All the treatments except T6, T7 and T8 received 25 kg P and 64 kg K /ha as TSP and MoP, respectively. Treatments T6, T7, T8 received NPK briquette fertilizer. Prilled urea (PU) was applied in three equal splits. Urea super granule (USG) and NPK briquettes were applied at 10 day after transplanting (DAT) and the briquettes were placed at 8-10 cm depth in the centre of four hills in alternate rows. The results demonstrate that all the yield components except 1000-grain weight responded significantly to the deep placement of N fertilizers in the form of USG and NPK briquette. The grain and straw yields of BRRI dhan29 were also influenced significantly due to deep placement of N fertilizers under AWD condition. The highest grain yield (6163 kg/ha) was recorded for T3 [USG, 130 kg N/ha) which was statistically similar with T4 (USG, 104 kg N/ha). The highest straw yield (6415 kg /ha) was also found in T3 [USG, 130 kg N/ha]. The lowest grain yield (3266 kg/ha) and straw yield (3637 kg/ha) were found in T1 (Control). The N uptake by BRRI dhan29, N use efficiency and apparent N recovery also showed significant response to the application of PU, USG and NPK briquettes. The maximum N use efficiency of 28.88% was noted in T5 followed by T4 with the value of 26.46% and the minimum value of 17.55% was observed in T2. The results revealed that the deep placement of N fertilizers accelerated the N uptake, N recovery and N use efficiency by BRRI dhan29. Based on grain yield and cost-benefit analysis, it can be concluded that application of 130 kg N/ha as USG is useful for the profitable cultivation of boro rice, BRRI dhan29.

Effect of Nitrogen and Water Management on Methane Emission of Boro Rice Cultivation in Bangladesh

Water and nitrogen are two key elements required for successful rice cultivation. We examined the responses of nitrogen and water management on methane emission of Boro rice in the field laboratory of Bangladesh Agricultural University research farm, Mymensingh. Three treatments were studied in the field experiment viz, T1: Control plot (no nitrogen fertilizer), T2: Urea super granule (78 kg N/ha), T3: Prilled urea (104 kg N/ha) with three replications under two water management of Continuous Standing Water (CSW) and Alternate Wetting and Drying (AWD). Air samples were collected by the closed-chamber method and methane gas was determined by gas chromatography. The highest CH4 emission was found from CSW plots and the lowest from AWD plots. Under CSW condition, the effects of urea treatments on CH4 emission were not significant. In case of urea treatments, the highest CH4 emission was observed from treatment T3 under CSW condition and T2 under AWD condition and the lowest emission was from the control treatment. The overall results suggest that prilled urea and urea super granule should be applied under AWD and CSW condition, respectively to keep less CH4 emission from irrigated rice agriculture.