Boro Season Research Articles

Weather Forecast Based Rice Advisory Services in Bangladesh

Strengthening the early warning system to forecast extreme weather and provide action-oriented advisories may increase rice yield as well as enhance the income of the farmers through minimizing risks and losses, if proper use of the generated advisory is ensured. This study assessed the importance and impact of weather forecast based advisory service (WFBAS) in Bangladesh. Literature review and field experimental data were used in a sensitivity analysis to show the impact of WFBAS on rice production. Available literatures suggested that the weather based advisory service would enhance rice yield by around 6.7-10%, but the experimental findings revealed that yield advantage could be 21.48%. Besides, the adoption of this technology would reduce the cost of cultivation by 12%, whereas the aggregate impact would increase the farmers’ profit by 25%. In the sensitivity study, we considered the production and price of Aman and Boro seasons (actual and government procured prices for 2018-19) and assumed only 6.70% yield increase with 5% farmers adopting of WFBAS. As such, additional 0.172 million tons will be added to the national rough rice production and thus the nation will be benefited by 3143 million Bangladeshi taka (BDT) at the actual farmgate price and it would be 4478 million BDT at the government procured price. The return on one BDT investment in this technology would be 51-73 BDT based on actual and procured prices. The projection showed enhenced production of the rough rice at 0.119 million tons and 0.214 million tons by 2025 and 2030, on which the additional return would be BDT 2441 and BDT 5223 million at the projected actual farmgate price and BDT 3522 and BDT 6979 million at the projected Government procured price, respectively. Hence, the successful implementation of the WFBAS will help to develop resilient rice farming communities, minimize livelihood risk, reduce the cost of production, utilize resources efficienty, and enable the farmers to take maximum benefit from favorable weather conditions through improved agricultural extension services. Finally, the enhanced yield and loss reduction will help to achieve the target of Sustainable Development Goal (SDG) by 2030 through sustaining rice production in Bangladesh under changing climate. Bangladesh Rice J. 25 (1) : 51-74, 2021

Productivity and Nutrient Balance of an Intensive Rice-Rice Cropping System Are Influenced by Different Nutrient Management in the Red and Lateritic Belt of West Bengal, India.

Rice is the lifeline for more than half of the world population, and in India, in view of its huge demand in the country, farmers adopt a rice–rice cropping system where the irrigation facility is available. As rice is a nutrient-exhausting crop, sustainable productivity of rice–rice cropping system greatly depends on appropriate nutrient management in accordance with the inherent soil fertility. The application of an ample dose of fertilizer is the key factor for maintaining sustainable rice yields and nutrient balance of the soil. Considering the above facts, an experiment was conducted on nutrient management in a rice–rice cropping system at the university farm of Visva-Bharati, situated in a sub-tropical climate under the red and lateritic belt of the western part of West Bengal, India, during two consecutive years (2014–2016). The experiment was laid out in a Randomized Completely Block Design with 12 treatments and three replications, with different rates of N:P:K:Zn:S application in both of the growing seasons, namely, kharif and Boro. The recommended (ample) dose of nutrients was 80:40:40:25:20 and 120:60:60:25:20 kg ha−1 of N:P2O5:K2O:Zn:S in the Kharif and Boro season, respectively. A high yielding variety, named MTU 7029, and a hybrid, Arize 6444 GOLD, were taken in the Kharif and Boro seasons, respectively. The results clearly indicated that the application of a recommended dose of nutrients showed its superiority over the control (no fertilizer application) in the expression of growth characters, yield attributes, yields, and nutrient uptake of Kharif as well as Boro rice. Out of the all treatments, the best result was found in the treatment where the ample dose of nutrients was applied, resulting in maximum grain yield in both the Kharif (5.6 t ha−1) and Boro (6.6 t ha−1) season. The corresponding yield attributes for the same treatment in the Kharif (panicles m−2: 247.9; grains panicle−1: 132.0; spikelets panicle−1: 149.6; test weight: 23.8 g; and panicle length: 30.6 cm) and Boro (panicles m−2: 281.6; grains panicle−1: 142.7; spikelets panicle−1: 157.2; test weight: 24.8 g; and panicle length: 32.8 cm) season explained the maximum yield in this treatment. Further, a reduction or omission of individual nutrients adversely impacted on the above traits and resulted in a negative balance of the respective nutrients. The study concluded that the application of a recommended dose of nutrients was essential for proper nutrient balance and sustainable yields in the rice–rice cropping system.

Leaching and runoff potential of nutrient and water losses in rice field as affected by alternate wetting and drying irrigation

Inefficient water management in rice paddy is responsible for a large quantity of water and nutrient loss, which causes tremendous economic and environmental costs. Yet, quantified data on the water and nutrient losses are limited. A study was conducted during 2018–2019 with an Aman (wet)-Boro (dry)-Aman (wet) rice rotation to evaluate the effect of water management on water and nutrient losses through different pathways. The treatments in 2018 Aman season were: (i) rainfed, (ii) I6D (irrigation after six days of ponded water disappearance), and (iii) I3D. In 2019, the Boro season had (i) I6D and (ii) I3D, and the Aman season had (i) rainfed, (ii) I9D, and (iii) I1D treatments. The water input and output from the studied lysimeters were measured daily, and samples from the leachates, ponded water, and topsoil were routinely analyzed for nutrient content. In both Aman seasons, the rainfed cultivation had lower percolation losses (38–44 % of total input) than other treatments (45–70 %). Evapotranspiration in the Boro season (5.4–5.9 mm/day) was higher than that in the Aman seasons (4.2–4.6 mm/day) because of the drier Boro season. Ammonium (NH4⁺-N) leached at 0.6–6.7 mg/L and nitrate (NO3⁻-N) 0.6–5.6 mg/L in these rice seasons. Phosphorus concentration ranged 0.04–0.37 mg/L in the leachates and 0.04–0.51 mg/L in the ponded water. The rainfed and I9D exerted higher nutrient leaching concentration in some events and less so for the I6D treatment than the I3D and I1D, possibly because of the better nitrification and preferential flow paths induced by the prolonged drying processes. However, the rainfed, I9D, and I6D had less leaching load than the I3D and I1D because the latter had larger percolation volume. For example, the I6D treatment in the Boro season reduced the N leaching load by 44 % and P load by 39 % compared with the I3D, and the I9D in 2019 Aman season had 42 and 13 % less N and P leaching load, respectively, than the I1D treatment. The findings will contribute to the effort of developing a sustainable and climate-resilient rice production system.

Establishment of Alternative Season for Cultivation of Photoperiod-Sensitive Traditional Rice Cultivars

Aims: To find out the suitable time for cultivating the photoperiod-sensitive rice cultivars during off-season.
 Study Design: Randomized Block Design.
 Place and Duration of Study: University Research Farm, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar 736165, West Bengal, India. Experiments were conducted during Boro 2017 and Kharif 2018.
 Methodology: Forty nine cultivars were sown in seed beds on 28th November, 2017 for cultivation of the Boro crop and sowing was done on 30th June, 2018 for cultivation of Kharif crop. Seedlings were transplanted in randomized block design with two replications. Row to row spacing was 30 cm and plant to plant spacing was 20 cm. Standard agronomic practices compatible to the humid tropic of Terai Zone were practiced. Ten random plants from each plot were selected for recording data. Observations were recorded on yield and yield attributing parameters.
 Results: High significant variation was observed for all the characters under study indicating the presence of high variability among the selected cultivars. Only the test weight between the two seasons had insignificant difference representing that there was no effect of seasons on this character. Time of sowing was standardized for sowing of the traditional cultivars in alternative season- Boro. The yield ranged from 0.35 t/ha to 2.68 t/ha during Boro and from 2.67 t/ha to 8.48 t/ha during Kharif. Ronga Komal (2.68 t/ha), Kauka (2.65 t/ha), Jaldhyapa (2.54 t/ha), Chakhao Angangbi (2.07 t/ha), Kaloboichi (1.87 t/ha), Kalturey (1.85 t/ha), Chakhao-Selection-2 (1.59 t/ha), Chakhao-Selection-1 (1.46 t/ha), Chakhao Sempak (1.43 t/ha) and Chakhao-Selection-3 (1.42 t/ha) performed well during Boro season.
 Conclusion: Ronga Komal, Kauka, Jaldhyapa, Chakhao Angangbi, Kaloboichi, Kalturey, Chakhao-Selection-2, Chakhao-Selection-1, Chakhao Sempak and Chakhao-Selection-3 performed well during Boro season. Consequently, those above varieties may be recommended for cultivation during Boro season.

BRRI Dhan100: A Zinc Enriched Rice Variety Suitable for Irrigated Ecosystem in Bangladesh

Recently released zinc enriched, high yielding, medium slender grain containing rice variety BRRI dhan100, appropriate for irrigated ecosystem of Bangladesh is an improvement over existing zinc enriched rice varieties for Bangladesh. The variety has satisfactorily passed the Proposed Variety Trial (PVT) conducted in the farmers’ field in Boro 2019-20 season. As a result National Seed Board (NSB) approved this variety for commercial cultivation in the Boro season (dry season) in 2021. It has modern plant type with 101 cm plant height and matures by 148 days. The proposed variety showed 1.20 t/ha higher yield than check variety BRRI dhan84. Identifying characters of this variety are green leaf, intermediate plant height, erect flag leaf, medium slender grain, intermediate leaf senescence grain. It can produce 7.7 - 8.8 t/ha grain yield. Thousand grain weight of the variety is 16.7 gm and head rice yield is 64%. The rice has zinc content 25.7 mg/kg, 26.8% amylose content with 7.8% protein content. The zinc enriched BRRI dhan100 is a superb variety for cultivating in the Boro season (dry) and farmers can be economically benefited and the country will be nutritionally benefited by the cultivation of BRRI dhan100.

Prevalence of Insects in Traditionally Stored Rice at Farmhouses in Bangladesh

A survey was conducted to investigate rice storage practices at the farmer’s level and the prevalence of insects’ status through a pretested questionnaire in Mymensingh and Jashore districts, Bangladesh. For seed purposes, large, medium, and small farmers store about 40, 10, and 5 kg, respectively in the Aman season for 7 months whereas in the Boro season large and medium farmers keep about 80 and 20 kg for 5 months. Average storage time was the highest (7 months) for Boro and Aman rice by large and small farmers, respectively for consumption. Eleven storage items namely, Dole, Motka, Tin, Plastic Drum, Gunny Bag, Bamboo Gola, Dhari, Bamboo Auri, Berh, Steel Drum, and Plastic Bag were found. About 57 and 74% of farmers stored rice, among them 47 and 58% used traditional Dole in Jashore and Mymensingh, respectively. Tin and Berh (1%) were the least used storage structures. About 11 and 17%; 3 and 4% of farmers used neem leaf and chemicals especially phostoxin in storage as an insect repellent in these areas, respectively. The use of Plastic Bags increased sharply due to lightweight, availability, and low price, whereas Bamboo Gola, Berh, Motka users decreased remarkably. Relative abundance of the insect species was: Rice Moth Sitotroga cerealla, Rice Weevil Sitophilus oryzae, Red Flour Beetle Tribolium castoreum, and Lesser Meal Worm Alphitobious diaperinus. Maximum insect infestation was found in stored paddy in Dole followed by Motka, and Plastic Bag; and the least amount was observed in Plastic Drum in both regions. Three fourth of the respondents took no measures to control insect pests in stored rice.

Integrated Weed Management Strategies for Sustainable Rice Production in Bangladesh

Weed causes huge reduction in crops yield, increases cost of cultivation, reduces input efficiency, interferes with agricultural operations, impairs quality, act as alternate hosts for several insect and diseases .Yield loss due to improper weeding at farmer’s field ranged from 4 to 22% depending on different rice ecosystem in Bangladesh. But at present considering all the cultivable land across the country and other issues; yield loss due to weeds considered about 2% in a consultation meeting.The present weed control practices in Bangladesh are characterized by intensive use of manual labour, use of herbicide and certain mechanical weeding. Manual weeding, besides laborious is inefficient as it is not done in time in most of the cases and always not practical because of various adverse conditions. Cost effective and integrated weed management system should be adopted to increase economic gain and sustainable rice production. Adopting timely and effectively appropriate weed management techniques we can reduce a significant amount of yield loss and about 0.43 million ton (MT) additional yield could be increased by 2030. To achieve the target weed management should be done from the very beginning of rice production and up to 30-35 DAP (days after planting) for Aus season, 35-40 DAT (days after transplanting) for T. Aman season and 40-45 DAT for Boro season which indicates critical period of weed infestation in Aus, T. Aman and Boro season. The main approach is that rice field have to keep free from weed up to that days by 2/3 hand weeding (HW) or application of herbicide fb (Followed by) 1HW or applying weeder fb 1HW which is called integrated weed management. Herbicide should be applied at proper time and dose which reduce 61% weeding cost. Mechanical weeding (MW) reduces 50% weeding cost that keeps environment friendly. Future weed science research specially herbicide efficacy with correct time and dose, new molecule herbicide with low environmental effect, herbicide residues in soil plant system, bioherbicide, allelopathic variety, weed competetive variety, mechanical weeder with related technological developments need a multidimensional approach for ecologically sustainable integrated weed management. Such a system will work toward a socially permissible, environmentally sound, economically feasible, productive and sustainable agricultural system. Bangladesh Rice J. 24 (2): 133-159, 2021

Soil Health as Influenced by Fertilizer Management in Rice Based Cropping System

Nutrient management influences soil health and crop productivity. Sustained crop production re-quires specific nutrient management options after a certain period. The objectives of this investigation were to examine the effects of inorganic and organic fertilization on yields and soil carbon budget under rice based cropping patterns in Bangladesh. The research data and informationhave been gen-erated based on previouslypublished, unpublished sources and own concept.Omission of K or im-balanced K are more influential for reduction in grain yield up to 47% in Boro (dry) season but N was most limiting up to 35% in T. Aman (wet) season. With existing fertilizer rates for growing rice, the balances of N and K are always negative. Balanced chemical fertilizer (NPKSZn) can be an option for improving crop productivity and maintain soil quality. Net ecosystem carbon (C) balances are posi-tive when 3 t ha-1 cow dung (CD), 2 t ha-1 poultry manure (PM) and 2 t ha-1 vermicompost (VC) are used in combination with chemical fertilizers. Soil amendments with organic nutrient sources (rice straw, CD, PM, VC, legume crops) and rice based cropping patterns such as T. Aman-Mustard-Boro, Boro-Fallow-Fallow, Jute-T. Aman-Fallow, Wheat-Mungbean-T. Aman, Grass pea- T. Aus-T. Aman and Potato-Boro-T. Aman can be beneficial in improving soil C budget, soil nutrient ratio, total crop production and maintenance of environmental health that will meet SDGs goal. Bangladesh Rice J. 24 (2): 119-131, 2021

Production and Acreage Growth and Seasonality in Rice in Bangladesh

Bangladesh is facing noticeable risks to self-reliance in rice production, considering the population and its future demand, land scarcity, intensity of natural disaster, soil degradation, global warming. In Bangladesh, rice is cultivated in three seasons which are known as Aus, Aman, and Boro. Considering the year from 1971 to 2015, the area of cultivation growth rate of Aus, Aman, and Boro were -3.4 percent, -0.01 percent, and 4.29 percent, respectively. The yearly yield growth rate of Aus, Aman and Boro were 2.13 percent, 2.48 percent, and 1.8 percent, respectively and production growth rate of Aus, Aman, and Boro were -1.3 percent, 2.45 percent, and 6.9 percent, respectively. During the period, overall rice cultivation area increased at the rate of 1.23 percent, the yield capacity increased at 3.42 percent. The total production increased at the rate of 4.19 percent. The yearly cultivated area growth of rice was 0.31 percent, yield growth was 2.9 percent, and production growth was 3.27 percent. The study found that Boro season rice contributed 2.29 times higher production compared to Aus, and 2.24 times to Aman.

Physiological Behaviour and Yield Contribution of Oryza sativa Under Different Cultivation System in Boro Season

Aims: The objectives of the research work were to evaluate the physiological behaviour and yield contributing attributes of rice under different system of cultivation in boro season.
 Study Design: The experiment was laid out in a randomized complete block design (RCBD) with three replications.
 Place and Duration of Study: Central research field of Sher-e-Bangla Agricultural University, Dhaka-1207 during November 2015 to May 2016.
 Methodology: In this research we used three System of cultivation [T1: Low land transplant (anaerobic) condition; T2: Raised upland (aerobic) condition, and T3: Raised transplant (aerobic) condition] and five rice Varieties [V1: BRRI hybrid dhan3; V2:Bolaka; V3: Moina; V4: Gold and V5:BRRI dhan 45], where different morpho-physiological data was taken for evaluation their performance. The significance of the difference among the treatment means were estimated by the Duncan’s Multiple Range Test (DMRT) at 5% level of probability [1].
 Results: Among the different system of cultivation significant variation was observed on growth, yield and yield contributing parameters. All the studied hybrid varieties showed superiority in respect of physiological characters, yield and yield attributes in anaerobic condition over aerobic condition. BRRI hybrid dhan3 provided the highest grain yield (8.05 t ha-1) at low land transplant condition. BRRI hybrid dhan3 performed well due to yield attributes [amount of chlorophyll (2.47 mg g-1) in its flag leaves,leaf area index (4.25), shoot reserve translocation (34.97%), grain dry matter accumulated from current photosynthesis (85.87%) , higher filled grains per panicle and 1000 grain weight] than others varieties and the lowest (4.28 t ha-1) was obtained from BRRIdhan45 at raised transplant condition.
 Conclusions: The results showed that Low land transplant condition with BRRI hybrid 3 showed the best performance regarding growth, yield and yield contributing characters of Boro rice varieties than others.

Effects of reduced rates of phosphorus and sulphur on the growth and yield of BRRI dhan29

Balanced fertilization is a pre-requisite for better rice production and it is necessary to determine optimum combination of nutrient elements for application. An experiment was conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during Boro season to investigate the effects of reduced rates of phosphorus (P) and sulphur (S) on the growth, yield, nutrient content and uptake by rice. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications and eight treatments viz. T1: Control, T2: Recommended Fertilizer Dose (RFD), T3: RFD -20% P, T4: RFD-40% P, T5: RFD-20% S, T6: RFD-40% S, T7: RFD-20% PS and T8: RFD-40% PS. The recommended fertilizer doses were 125 kg N ha-1, 25 kg P ha-1, 70 kg K ha-1, 15 kg S ha-1 and 3 kg Zn ha-1 supplied from urea, TSP, MoP, gypsum and zinc sulphate, respectively. There was significant effect of reduced rates of P and S fertilizers on rice yield compared to control. The highest grain yield of 5.10 t ha-1 and straw yield of 7.02 t ha-1 were recorded from treatment T2 (RFD) that produced the maximum values of all the yield components and the highest content and uptake of nutrients. The performance of T2 and T3 (RFD - 20% P) was statistically similar in producing yield parameters, yields, nutrient contents and uptake by rice. Again, 20% reduced rate of S (T5) or of P and S (T7) caused significant yield reduction, poor yield parameters and less nutrient uptake compared to T2. Thus, the recommended fertilizer dose and the treatments where 20% P was reduced from the RFD are equally efficient in increasing yield as well as enhancing nutritional quality of rice. This reduction of chemical fertilizer could help lessen the cost of rice production with decreasing environmental risk.
 Asian J. Med. Biol. Res. March 2021, 7(1): 40-47

Heterobeltiosis and Economic Heterosis for Grain Yield Related Traits of Boro Rice (Oryza sativa L.)

Rice is a staple food for more than half of the world’s population and to increase the yield potential of rice would be a key factor for mitigating global demands of about 810 million tons of rice by 2025. To exploit the economic importance of heterosis, quantitative valuation was carried out in a randomized complete block design with three replications for 16 agronomic traits of 5x5 half diallel populations during boro season of 2017-2018. Diallel populations were generated by using five selected parents (P1: BRRI dhan28, P2: BRRI dhan74, P3: BINA dhan10, P4: IR59418-7B-21-3 and P5: BRRI dhan67) where, P1 was considered as standard check to estimate the economic heterosis. Analysis of variance revealed highly significant variability among the genotypes for most of the traits except grain length and length-breadth ratio. The results showed that none of the hybrid combination performed better for all the traits over the three types of heterosis. The highest relative heterosis was recorded in P3×P4 followed by P4×P5 for grain yield plant-1, filled grains panicle-1, effective tillers plant-1. Majority of the cross combinations (>60%) revealed highly significant positive heterosis for grain yield plant-1 over mid parent. Heterobeltiosis for grain yield plant-1 was observed significant for 50% cross combinations and could be utilized in hybrid breeding. Whereas, more than 70% crosses exhibited undesirable negative standard heterosis for grain yield plant-1. Only two cross combinations (P3×P5 and P3×P4) among ten revealed significant positive economic heterosis for grain yield plant-1 and those could be exploited in rice breeding.
 Int. J. Appl. Sci. Biotechnol. Vol 9(1): 45-53

Adjusting planting time of Binadhan-17 in boro season

Boro rice (grown in winter under irrigated condition) contributes to the major portion of rice production (over 50%) in Bangladesh. Binadhan-17 is a green super rice developed by BINA which requires 30% less nitrogenous fertilizer and water which is grown in aman season (primely produced under rainfed). Due to it’s increasing popularity and adoption rice growers are keen to cultivate it in boro season also. Taking account of the above situation, two field trials were conducted at Magura during November 2019 to May 2020 to investigate the effect of variety, sowing dates and their interaction. Factorial RCBD (Randomized Complete Block Design) was applied for experimentation. Two rice varieties: Binadhan-17 (V1), BRRI dhan58 (V2) and three sowing times: 30th November (T1), 10th December (T2), 20th December (T3) were used as treatments. 35 days old seedlings were transplanted in main field. Relevant agronomic and morphological data were statistically analyzed through Statistix 10.0. Combined effect of the above factors at farm exposed that, T1×V1 required longest days (159.33 days) to mature. but, comparatively short life cycle (149.97 days) was observed by T3×V2. Maximum grain was yielded (7.70 t/ha) by T2×V1 and minimum (5.74 t/ha) by T1×V1 treatment combination. Outcomes of on station revealed that, T1×V1 needed more days (158.00 days) to mature; conversely, alike duration was noted with T2×V2 (147.20 days) and T3×V2 (145.43 days) which matured quite earlier. T2×V1 produced the highest grain yield (7.41 t/ha) and T1×V2 the lowest (5.94 t/ha). Our results indicate that, planting of Binadhan-17 on 10th December may give insect-disease free grains with optimum yield in context of Magura region. Farmers will be financially benefited if they cultivate this variety in the boro season in lieu of aman; due to higher yield

Organic Amendment on Soil Quality and Yield Performance of Dry Direct Seeded Boro Rice

An experiment was conducted at Khitrokashipur, Durgapur, Rajshahi during March to June 2018 to study the effect of organic amendment on soil quality and yield performance of dry direct seeded boro rice var. BRRI dhan28. The treatments were Trichocompost (TC), Vermicompost (VC), mustard oil cake (MOC), Trichocompost + mustard oil cake (TC+MOC), Vermicompost + mustard oil cake (VC + MOC), and no amendment control. The experiment was laid out in a randomized complete block design with three replications. Trichocompost and Vermicompost were applied @ 3 t ha-1, while mustard oil cake was used @ 0.5 t ha-1. The results revealed that Trichocompost and vermicompost fertilization exerted significant influence on yield performance of BRRI dhan28 in boro season. The treatment trichocompost (T1) @ 5 t ha-1 produced the highest grain yield (5.95 t ha-1), while the mustard oil cake (T3) @ 0.5 t ha-1 the highest effective tillers hill-1 (15.33), though the highest straw yield (5.46 t ha-1) was produced in the treatment VC + MOC (T5). In case of soil properties, Trichocompost (T1) @ 3 t ha-1 and mustard oil cake (T3) @ 0.5 t ha-1 improved soil organic matter content, while Trichocompost (T1) @ 3 t ha-1 and Vermicompost (T2) @ 0.5 t ha-1 improved phosphorus and potassium content. Field capacity was greatly influenced by Trichocompost (T1) @ 3 t ha-1 and Vermicompost + mustard oil cake (T5). Soils with Trichocompost (T1) @ 3 tha-1 showed the highest bulk density. It was concluded that organic amendment greatly improved the yield performance of BRRI dhan28 and also soil physical and chemical properties under dry direct seeded boro rice cultivation system.
 Bangladesh Agron. J. 2020, 23(2): 103-109

Influence of integrated use of cotton seed oilcake and mustard oilcake with chemical fertilizers on growth, yield and nutritional quality of rice

Cotton seed oilcake and mustard oilcake are excellent and high quality organic manures enriched with essential nutrient elements. A field experiment was carried out at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during boro season of 2019 to investigate the influence of cotton seed oilcake and mustard oilcake on yield attributes, yield, nutrient content and uptake by rice cv. BRRI dhan29. The experiment was laid out in a Randomized Complete Block Design (RCBD) with four replications and seven treatments viz. T1: control, T2: 100% Recommended Fertilizer Dose (RFD), T3: 50% RFD, T4: 50% nitrogen (N) from RFD + 50% N from cotton seed oilcake, T5: 50% N from RFD + 50% N from mustard oilcake, T6: 50% N from RFD + 25% N from cotton seed oilcake + 25% N from mustard oilcake, T7: 50% N from cotton seed oilcake + 50% N from mustard oilcake. The maximum values of all the yield components viz. plant height, panicle length, number of effective tillers hill-1 and filled grains panicle-1 and yields (grain and straw) were found in treatment T2. The highest content and uptake of nutrients – N, P, K and S were also recorded in T2. The performance of T4 and T2 was statistically similar in producing yield parameters, grain and straw yields, nutrient contents and uptake by rice. Among the integrated approaches, the performance of T4 was the best as it produced the second highest grain yield of 6.24 t ha-1 and straw yield of 8.17 t ha-1 with higher nutritional improvement of rice. Application of cotton seed oilcake compensated up to 50% of chemical fertilizer. Therefore, considering the significance of organic manures and soil health, cotton seed oilcake should be considered for application in association with chemical fertilizers for yield enhancement and nutritional improvement of rice.
 Progressive Agriculture 31 (3): 144-153, 2020

Comparison of Methods to Evaluate Rice (Oryza sativa) Germplasm for Tolerance to Low Temperature at the Seedling Stage

Low temperature stress at the seedling stage is a major constraint to rice (Oryza sativa) production. Previously developed screening protocols typically germinate seed and establish seedlings under warm constant-temperature conditions that are optimal for growth, prior to initiating a constant low-temperature challenge. We developed three controlled-environment protocols mimicking extreme cold boro (winter) seasons based on 25 years weather data from Bangladesh to test the hypothesis that by more closely replicating field conditions, greater information about cultivars could be obtained compared to standard protocols. Root and shoot growth after germination in a Petri dish at 20 °C for three weeks gave similar results as visual scores of transplanted seedlings in a standard five-week protocol. Moreover, transplanted seedlings at the end of the nine-week mimic protocols showed large differences in height and dry biomass, whereas for the standard protocols, growth during the warm pre-treatment substantially masked these genotypic differences. Thus, initial screening of large rice germplasm panels can be most efficiently accomplished with a short-duration germination test at low temperature. However, more effective differentiation of cultivars can be accomplished by measuring transplanted seedling growth from the newly-developed mimic protocols. These results will facilitate the development of improved rice cultivars.

Impact of Climatic Variables on Major Field Crops in Char Areas of Mymensingh District

An agro-climatic study was conducted at different areas (Bhatiapara, Kashiar Char and Morichar Char) of Mymensingh district with 25 years of climatic data (i.e., temperature, humidity and rainfall) to observe the climatic variability and their impact on the productivity of three types of crops such as Boro, Jute and Wheat. Production of all the three crops were found as increasing. In Boro season, the production increased by 0.057 ton per hectare per year. Jute production increased by 0.029 ton per hectare and Wheat production increased by 0.067 ton per hectare in each year, respectively. Humidity has influence on seasonal Boro production whereas temperature and rainfall didn’t influence the production. Temperature has influences on both Jute and Wheat production. From correlation analysis, it was revealed that average humidity has considerable influence on seasonal Boro production than all other crops. However, most of the time the production showed increasing trend with some exceptions. The study recommends that local adaptation practices should be scrutinized, the role of institutional support should be highlighted and national adaptation strategies and resilience should be strengthened.
 Environ. Sci. & Natural Resources, 12(1&2): 51-55, 2019

Assessing the Level of Comparative Advantage for the Boro (Dry) Rice Production in Bangladesh: A Time Series Analysis

This study aims to investigate whether Bangladesh has a comparative advantage in producing rice in the long run for the Boro season. With that view, we estimated “Domestic Resource Cost (DRC)” as an indicator of comparative advantage using the time series data. Data were obtained from the food situation database, published by the Food Planning and Monitoring Unit, Ministry of Food, Peoples’ Republic of Bangladesh. The analyses show that Bangladesh has a comparative advantage in modern rice production in the Boro season at import substitution. DRC values for Boro season are less than 1 in all the periods (2010/11 to 2019/20) except 2018/19. The sensitivity analysis shows that all the indicators pertinent to this particular analysis strongly influence DRC values. The government and policymakers should focus on price spread between the wholesale to retail levels, the border price of rice at the farm gate level, and the border prices of rice, urea, TSP, and MoP of farm gate level to achieve a long-run comparative advantage. Research efforts need to be prioritized for developing new varieties, especially for the Boro season with higher yield potential.

Development of Environment Friendly Paddy Ecosystem for Sustainable Rice Farming through Soil Amendments with Biochar and Alternate Wetting-Drying Irrigations

Climate change may badly affect the availability of water and soil nutrients to rice plant. Research experiments were conducted at the Environmental Science Departmental field, Bangladesh Agricultural University, Mymensingh during July 2017 to June 2019, to find out the suitable combination of biochar with inorganic fertilizers for minimizing seasonal yield scaled CH4 emissions, reducing global warming potentials (GWPs) and sustainable rice farming under feasible irrigation practices. There were ten experimental treatments with different combinations of inorganic NPKS fertilizers and biochar (15 - 30 t/ha) under conventional flooding (CF) and alternate wetting-drying irrigations (AWDI). This study revealed that NPKS fertilization (50% of the recommended doze) with 15 t/ha biochar amendments under AWD irrigation maximized rice yield 6750 kg/ha and 4380 kg/ha in dry boro and wet aman seasons respectively, while the lowest rice yield 1850 kg/ha and 1550 kg/ha were recorded in continuously irrigated control treatment (T1) during the dry and wet seasons respectively. Seasonal cumulative CH4 emission, yield scaled CH4 emission and GWPs were suppressed significantly with biochar amendments 15 - 30 t/ha under both conventional and AWDI irrigation systems during the wet and dry seasons of rice cultivation. Significant interactions were observed among biochar amendments and irrigation practices during the dry boro rice cultivation. Dry seasonal cumulative CH4 emissions were decreased by 14.7%, 18.9% and 24.8% with biochar amendments at 15 t/ha, 20 t/ha and 30 t/ha respectively under conventional irrigation; while cumulative CH4 emissions were reduced by 10.6%, 26% and 41.6% respectively, under AWDI system. Finally, total global warming potentials (GWPs) were decreased by 6% - 15%, 13% - 30% with biochar amendments under conventional and AWDI irrigations respectively, in wet season; while global warming potentials (GWPs) also decreased by 14% - 25%, 11% - 42% with biochar amendments under conventional and AWDI irrigations, respectively, in the dry boro season. Biochar amendments increased water productivity index to some extent, but AWD irrigations significantly increased water productivity over the conventional irrigation in both wet and dry seasons. After experimental period, it was found that soil porosity, redox status, soil organic carbon (SOC) as well as overall soil properties were improved significantly with biochar amendments and AWD irrigations. Conclusively, biochar amendments @15 - 20 t/ha with half of the recommended inorganic (NPKS) fertilizers under alternate wetting-drying irrigations revealed an environment friendly integrated package approach to reduce seasonal cumulative CH4 emissions as well as GWPs, while improving rice rhizosphere environment and rice productivity to meet the national food security.

Response of rice hybrids to irrigation levels for yield, quality and water use during boro season in lower Gangetic plains of West Bengal

The effect of irrigation regimes (irrigation at 1, 3 and 5 days interval) on four rice hybrids (6129 Gold, 6444 Gold, Tej Gold and DRH 775) was studied in split plot design during dry (boro) season of 2017 at Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal. Mean cultivar days to 50% flowering and maturity of hybrid rice were 99.1 and 125.9 days, respectively; while total summed GDD, HTU and PTU for entire life cycle were 1656°C day, 10410°C hour and 20311°C hour, respectively. Irrigation at 1 day interval resulted in highest grain yield (5.92 t ha-1), heat use efficiency (3.62 kg ha-1 °C day-1) and head rice recovery (58.2%), but lowest (3.08 kg ha-1 mm-1) water use efficiency (WUE). Among four hybrids, 6129 Gold yielded highest (5.88 t ha-1) with maximum WUE (4.44 kg ha-1 mm-1) and high-intermediate gelatinization temperature (score 3.0), that yield was 0.31, 0.42 and 0.51 t ha-1 greater over Tej Gold, DRH 775 and 6444 Gold, respectively. Irrigation regime could influence a few grain quality parameters viz. brown rice (73.8-75.6%), head rice recovery (53.3-58.2%) and alkali spreading score (score 3.2-4.1) in the investigation. Irrigation at 3 days interval might be adopted due to better WUE (5.02 kg ha-1 mm-1) with moderate grain yield (5.80 t ha-1) during boro season in lower gangetic plains of West Bengal.