Agronomy and Soil Science of Biochar

Below, is a catalogue of Bangladeshi research on biochar. The studies show some seemingly contradictory effects of biochar. However, the properties of biochars differ greatly depending on what they are made from, how they are made, and how they are used. For example, we would expect that biochar made in gasifier stove at 700-1000°C is more poreous and stable than biochar made in an oxygen-limited reactor at 350°C.

Research Papers

Mia, S; Uddin, ME; Kader, MA; Ahsan, A; Mannan, MA; Hossain, MM; Solaiman, ZM. 2018. Pyrolysis and co-composting of municipal organic waste in Bangladesh: A quantitative estimate of recyclable nutrients, greenhouse gas emissions, and economic benefits. Waste Management 75: 503-513 DOI: 10.1016/j.wasman.2018.01.038 Expand ABSTRACT

ABSTRACT: Waste causes environmental pollution and greenhouse gas (GHG) emissions when it is not managed sustainably. In Bangladesh, municipal organic waste (MOW) is partially collected and landfilled. Thus, it causes deterioration of the environment urging a recycle-oriented waste management system. In this study, we propose a waste management system through pyrolysis of selective MOW for biochar production and composting of the remainder with biochar as an additive. We estimated the carbon (C), nitrogen (N), phosphorus (P) and potassium (K) recycling potentials in the new techniques of waste management. Waste generation of a city was calculated using population density and per capita waste generation rate (PWGR). Two indicators of economic development, i.e., gross domestic product (GDP) and per capita gross national income (GNI) were used to adopt PWGR with a projected contribution of 5-20% to waste generation. The projected PWGR was then validated with a survey. The waste generation from urban areas of Bangladesh in 2016 was estimated between 15,507 and 15,888 t day(-1) with a large share (similar to 75%) of organic waste. Adoption of the proposed system could produce 3936 t day(-1) biochar blended compost with an annual return of US $210 million in 2016 while it could reduce GHG emission substantially (-503 CO2 e t(-1) municipal waste). Moreover, the proposed system would able to recover similar to 46%, 54%, 54% and 61% of total C, N, P and K content in the initial waste, respectively. We also provide a projection of waste generation and nutrient recycling potentials for the year 2035. The proposed method could be a self-sustaining policy option for waste management as it would generate similar to US$51 from each tonne of waste. Moreover, a significant amount of nutrients can be recycled to agriculture while contributing to the reduction in environmental pollution and GHG emission.

Shashi, M; Mannan, M; Islam, M; Rahman, M. 2018. Impact of rice husk biochar on growth, water relations and yield of maize (Zea mays L.) under drought condition. The Agriculturists, 16(2): 93-101. Expand ABSTRACT

ABSTRACT: The present experiment was conducted to study the impact of rice husk biochar on growth, water relations and yield of maize (BARI Hybrid Bhutta- 9) under drought (60 and 40% of FC) conditions. Four doses of rice husk biochar @ 0, 5, 10 and 20 t/ha were applied as an amendment in soil before sowing of seeds. Results revealed that drought stress reduced plant height, relative water content and grain yield of maize. But rice husk biochar at different doses improved the above mentioned characters under drought conditions. Under 60% of FC, the highest plan height, leaf water content and yield were 196.67 cm, 79.86% and 89.75 g/plant, respectively when biochar was applied @ 20 t/ha but it was 173.33 cm, 78.32% and 84.57 g/plant, respectively under 40% of FC when biochar was applied at the same dose. It may be concluded that, rice husk biochar @ 20 t/ha showed the best result to promote growth, water relation traits and yield of maize under drought condition.

Piash, MI; Hossain, MdF; Anyanwu, IN; Al Mamun, S; Parveen, Z. 2018. Effect of biochar application on soil carbon fluxes from sequential dry and wet cultivation systems. American Journal of Climate Change 7: 40-53. Expand ABSTRACT

ABSTRACT: Application of biochar has been highly credited for its potential to sequester carbon and GHG mitigation from tropical agro-ecosystems. However, experiments show inconsistent results depending on soil and biochar type, cultivation system, climatic condition and the type of evolved GHGs. This study emphasized on the effect of biochar on carbon emission trends from a sequential dry and wet cultivation system of Bangladesh. An incubation study was conducted with two contrasting soils and eight different treatments viz. control, only fertilizer, three different biochars (10 t·ha−1) with and without recommended fertilizer dose. Results revealed the fact that, emission of carbon was substantially higher from Sara soil than Kalma soil. Biochar treatments did not have any easing effect on CO2 emission at field condition; rather, increased in most of the cases. However, emission was significantly (P < 0.05) suppressed at submerged condition by biochar application. Non-fertilized water hyacinth biochar was most effective in this regard. In general, fertilizer application caused higher emission of CO2. Biochar application was ineffective to control CH4 and CO release to atmosphere and submergence further intensified their emission significantly. The overall results indicate that applied biochars have negligible effect on carbon emission except for reducing CO2 from submerged soils.

Khan, TF; Didar-Ul-Alam, M. 2018. Effects of biochar on legume-Rhizobium symbiosis in soil. Bangladesh Journal of Botany 47(4):945-952. Expand ABSTRACT

ABSTRACT: An in vitro study was conducted to observe the effects of tannery waste and biochar on soil bacterial population particularly legume-Rhizobium symbiosis. The study comprised a total of seven different treatments including a control. Count of total bacteria and Rhizobium was observed on initial materials and on all treated soils. A leguminous plant, cowpea, was used to study the effects on nitrogen fixation which could be further linked to legume-Rhizobium symbiosis. Bacterial population was higher in tannery waste treated soils than the corresponding biochar treated ones. It was found that waste treated soils had higher Rhizobium count than the biochar treated ones. Nitrogen fixation was found to be higher in tannery waste than biochar treatments. Although there appeared to be no adverse impact on legume-Rhizobium symbiosis, growth of bacteria particularly Rhizobium was inhibited indicating that microbial functioning of the soil might be affected and thereby likely to jeopardize agricultural production and food security.

Ahmed, F; Islam, MS; Iqbal, MT. 2017. Biochar amendment improves soil fertility and productivity of mulberry plant. Eurasian Journal of Soil Science. 6(3):226-237. DOI:10.18393/ejss.291945 Expand ABSTRACT

ABSTRACT:Biochar has the potential to improve soil fertility and crop productivity. A field experiment was carried out at the experimental field of Bangladesh Sericulture Research and Training Institute (BSRTI), Rajshahi, Bangladesh. The objective of this study was to examine the effect of biochar on soil properties, growth, yield and foliar disease incidence of mulberry plant. The study consisted of 6 treatments: control, basal dose of NPK, rice husk biochar, mineral enriched biochar, basal dose + rice husk biochar and basal dose + mineral enriched biochar. Growth parameters such as node/meter, total branch number/plant, total leaf yield/hectare/year were significantly increased in basal dose + mineral enriched biochar treated plot in second year compared with the other fertilizer treatments. In second year, the total leaf yield/hectare/year were also 142.1% and 115.9% higher in combined application of basal dose + mineral enriched biochar and basal dose + rice husk biochar, respectively, than the control treatment. The soil properties such as organic matter, phosphorus, sulphur and zinc percentage were significantly increased with both the (mineral enriched and rice husk) biochar treated soil applied with or without recommended basal dose of NPK than the control and only the recommended basal dose of NPK, respectively. Further, the lowest incidences of tukra (6.4%), powdery mildew (10.4%) and leaf spot (7.6%) disease were observed in second year under mineral enriched biochar treated plot than the others. The findings revealed that utilization of biochar has positive effect on the improvement of soil fertility and productivity as well as disease suppression of mulberry plant.

Iqbal MT. 2017. Utilization of biochar in improving yield of wheat in Bangladesh. Bulgarian Journal of Soil Science 2(1):53-74. Expand ABSTRACT

ABSTRACT: Biochar is a carbon-rich co-product resulting from pyrolysis process. Biochar amendment to soil can improve productivity of wheat plant. Therefore, the utilization of biochar in improving yield of wheat in Bangladesh was investigated in this study. Soil pH decreased 0.8 units and organic matter increased 0.67% after 159 days of incubation for the biochar amendment. Several yield parameters was similar between Bangladesh Agricultural Research Council (BARC) recommended fertilizer and half of BARC recommended fertilizer plus rice straw added treatment. This study also found that the combination of rice straw biochar with half of BARC recommended fertilizer gave better effect than single application rice straw biochar as well as gave the highest yield of wheat in the same treatment. Rice straw biochar can have the potential to decrease dependence on chemical fertilizer for wheat production. Therefore, utilization of biochar is a viable option to improve yield of wheat in Bangladesh.

Ahiduzzaman, M; Islam, AKMS. 2016. Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation. SpringerPlus (2016) 5:1248 DOI: 10.1186/s40064-016-2932-8. Expand ABSTRACT ABSTRACT: Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production.

Mete, FZ; Mia, S; Dijkstra, FA; Abuyusuf, M; Hossain, ASMI. 2015. Synergistic effects of biochar and NPK fertilizer on soybean yield in an alkaline soil. Pedoshpere 25: 713-719 DOI: 10.1016/S1002-0160(15)30052-7 Expand ABSTRACT

ABSTRACT: Biochar effects on legume growth and biological nitrogen fixation have been studied extensively, mostly in acidic soils with laboratory produced biochar. In the present study, a pot experiment in a full factorial experimental design was performed to examine soybean yield and nodulation of three genotypes grown with or without biochar and NPK fertilizers in an alkaline soil. We observed synergistic effects of biochar and NPK fertilizer applications on biomass and seed yields for all three soybean genotypes. Total biomass production and seed yield increased on average by 67% and 54%, respectively, with biochar and by 201% and 182% with NPK fertilizer application compared to the control. When applications of biochar and NPK fertilizer were combined, the increases were 391% and 367%, respectively. However, the biomass production in the control was very low (692 kg ha(-1)) due to a high soil pH (8.80). The nodulation increased with biochar and NPK fertilizer applications, and was largest with the combined application. A correlation was found between leaf chlorophyll content (single photon avalanche diode value) and nodule number. We suggested that the synergistic increase in yield was due to a decrease in soil pH caused by biochar and NPK fertilizer applications thereby increasing P availability in this alkaline soil.

Ali, MA; Kim, PJ; Inubushi, K. 2015. Mitigating yield-scaled greenhouse gas emissions through combined application of soil amendments: A comparative study between temperate and subtropical rice paddy soils. Science of the Total Environment 529: 140-148 DOI: 10.1016/j.scitotenv.2015.04.090 Expand ABSTRACT

ABSTRACT: Effects of different soil amendments were investigated on methane (CH4) and nitrous oxide (N2O) emissions, global warming potential (GWP) and yield scaled GWPs in paddy soils of Republic of Korea, Japan and Bangladesh. The experimental treatments were NPK only, NPK + fly ash, NPK + silicate slag, NPK + phosphogypsum(PG), NPK + blast furnace slag (BFS), NPK + revolving furnace slag (RFS), NPK + silicate slag (50%) + RFS (50%), NPK + biochar, NPK + biochar + Azolla-cyanobacteria, NPK + silicate slag + Azolla-cyanobacteria, NPK + phosphogypsum (PG) + Azolla-cyanobacteria. The maximum decrease in cumulative seasonal CH4 emissions was recorded 29.7% and 32.6% with Azolla-cyanobacteria plus phosphogypsum amendments in paddy soils of Japan and Bangladesh respectively, followed by 22.4% and 26.8% reduction with silicate slag plus Azolla-cyanobacteria application. Biochar amendments in paddy soils of Japan and Bangladesh decreased seasonal cumulative N2O emissions by 31.8% and 20.0% respectively, followed by 26.3% and 25.0% reduction with biochar plus Azolla-cyanobacteria amendments. Although seasonal cumulative CH4 emissions were significantly increased by 9.5-14.0% with biochar amendments, however, global warming potentials were decreased by 8.0-12.0% with cyanobacterial inoculation plus biochar amendments. The maximum decrease in GWP was calculated 22.0-30.0% with Azolla-cyanobacteria plus silicate slag amendments. The evolution of greenhouse gases per unit grain yield (yield scaled GWP) was highest in the NPK treatment, which was decreased by 43-50% from the silicate slag and phosphogypsum amendments along with Azolla-cyanobacteria inoculated rice planted soils. Conclusively, it is recommended to incorporate Azolla-cyanobacteria with inorganic and organic amendments for reducing GWP and yield scaled GWP from the rice planted paddy soils of temperate and subtropical countries.

Mia, S; Uddin, N; Al Mamun Hossain, SA; Amin, R; Mete, FZ; Hiemstra, T. 2015.  Production of biochar for soil application: A comparative study of three kiln models. Pedosphere 25: 696-702 DOI: 10.1016/S1002-0160(15)30050-3 Expand ABSTRACT

ABSTRACT: Biochar has potentials for soil fertility improvement, climate change mitigation and environmental reclamation, and charred biomass can be deliberately incorporated into soil for long-term carbon stabilization and soil amendment. Many different methods have been used for biochar production ranging from laboratory to industrial scales. However, in countryside of developing countries, biomass is generally used for cooking but not charred. Biochar production techniques at farmer scale have remained poorly developed. We developed and tested biochar production kilns for farmers with a dimension of 50.8 cm x 38.1 cm (height x diameter), using three different setups for optimizing oxygen (O-2) limitation and syngas circulation: airtight with no syngas circulation (Model I), semi-airtight with external syngas circulation (Model II) and semi-airtight with internal syngas circulation (Model III). A comparative assessment of these biochar production kiln models was made considering biochar pyrolysis time, fuel to biomass ratio, biochar to feedstock ratio and thermogravimetric index (TGI). Among the models, the best quality biochar (TGI = 0.15) was obtained from Model I kiln taking the longest time for pyrolysis (12.5 h) and the highest amount of fuel wood (1.22 kg kg(-1) biomass). Model III kiln produced comparatively good quality biochar (TGI = 0.11), but with less fuel wood requirement (0.33 kg kg(-1) biomass) and shorter pyrolysis time (8.5 h). We also tested Model III kiln in a three times larger size under two situations (steel kiln and pit kiln). The biochar to feedstock ratio (0.38) and quality (TGI = 0.14) increased slightly for the larger kilns. Quality of biochar was found to be mainly related to pyrolysis time. The costs for the biochar stove and pit kiln were US$ 65-77, while it was US$ 154 for the large size steel kiln. Model III kiln can potentially be used for both cooking and biochar production at farmer scale.

Khan KT; Chowdhury MT; Huq SI. 2015. Effects of biochar on the fate of the heavy metals Cd, Cu, Pb and Zn in soil. Bangladesh Journal of Scientific Research. 2015;28(1):17-26. Expand ABSTRACT

ABSTRACT: An in vitro incubation study was conducted with soil having seven applications of different treatments of biomass and biochar including a control. The biochar and biomasses were applied at a rate of 5 t ha-1 and incubated at field moisture condition for 30, 60 and 90 days individually in different pots. 0.005M DTPA and 1M HCl extractable cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) contents were determined at 30, 60 and 90 days of incubation. The phytoavailable fraction of Cd, Cu, Pb and Zn as extracted with the 0.005M DTPA revealed that biochar did not retain any substantial amount of any of these metals. 1M HCl extracted higher amounts of heavy metals than 0.005M DTPA. Neither biochar nor its source biomass had any sorptive effect on the labile fraction of Pb and Cd present in soil. 1M HCl extracted not only a portion of these metals from the soils but also that present in the biochar and biomass. The general idea that biochars are able to complex metal ions on their surfaces and therefore, reduce bioavailability, however, was not reflected in the present study.

Khan KT; Chowdhury MT; Huq SI. 2014. Application of biochar and fate of soil nutrients. Bangladesh Journal of Scientific Research. 2014; 27(1):11-25. DOI 10.4236/ajcc.2018.71005 Expand ABSTRACT

ABSTRACT: An in vitro incubation study was conducted with soil having seven applications of different treatments of biomass and biochar including a control. The biochar and biomass were applied at a rate of 5 t/h a and incubated at field moisture condition for 30, 60 and 90 days individually in different pots. Total organic carbon (C), total nitrogen, phytoavailable nitrogen (N), phosphorus (P), sulfur (S) and potassium (K) were determined at the end of each incubation period. Total soil organic carbon (SOC), showed a substantial declining trend in all the soils – more prominent in the biochar treated soils than its corresponding biomass treated soils. The pH, total N, phytoavailable N, P, K were substantially higher in the biochar treated soils irrespective of the incubation days compared to the biomass treated soils. Conversely, the available S contents of the biochar treated soils were lower than that of biomass treated soils. The effect of biochar on these nutrients vis-à-vis soil health is discussed.

Khan, TF; Huq, SMI. 2014. Effect of biochar on the abundance of soil bacteria. British Microbiology Research Journal, 4(8): 896-904 Expand ABSTRACT

ABSTRACT: A pot experiment was conducted to study the effect of biochar on the abundance of soil bacteria and compare it with the source biomass. Seven different treatments and a control were used in the experimental set-up. Three different types of biomass were selected and three types of biochar were produced from them. Both the materials were applied to the soil at a rate of 5t/ha. All treatments were incubated for 30, 60 and 90 days. Cultural, microscopic and biochemical tests were carried out to identify the bacterial isolates in soils treated with biochar and its source biomass. Bacterial isolates identified in soil and in some of the biomasses before treatments were applied include Bacillus badius, Bacillus krulwichiae, Bacillus siralis, Bacillus sylvestris, Bacillus flexus, Aneurinibacillus aneurinilyticus and Bacillus thuringiensis while after incubation periods, seven new isolates were identified. This was true for the biomass treated soils where additional one to two isolates reappeared. Conversely, in the biochar treated soils, most of the isolates disappeared except Bacillus badius that survived in all soils till 90 days. Because of its tolerant nature, it was further investigated for cellulase enzyme activity. Interestingly, the isolate did not show any such activity. Conclusively, biochar application may exert negative effect on the distribution and proliferation of soil bacteria with possible effect on soil quality and crop production.

Mia, S; Abuyusuf, M; Sattar, MA; Islam, ABMS; Hiemstra, T; Jeffery, S. 2014. Biochar amendment for high nitrogen and phosphorous bioavailability and its potentiality of use in Bangladesh agriculture: a review. Journal of the Patuakhali Science and Technical University 5(l): 145-156 Expand ABSTRACT

ABSTRACT: Biochar application to soil is increasingly attracting scientists’ attention for its multifaceted benefits from carbon sequestration to soil fertility improvement. However, the mechanistic understanding of high soil fertility and consequently high yield is still to be elucidated. The present study was aimed at reviewing the present state of knowledge regarding biochar effects on N and P availability with especial attention to potentiality, feasibility and justification of biochar addition to our soil. Biochar addition increases the mineral N retention due to NH4+ capture at cation exchange sites, NO3- adsorption in the base functional group at high pH or due to physical NO3- sorption. Microbial immobilization is also responsible for N retention and recycling. Phosphorous availability also increases after biochar amendment as it increases soil pH and releases high charged small molecule humic acids. Biochar addition to our soil would be a potential option for increasing soil organic matter content, fertlhzer use efficiency if it could be produced from huge amount of agro-industrial, municipal and house hold waste.

Mahmud K; Chowhdhury MS; Noor N; Huq SI. 2014. Effects of different sources of biochar application on the emission of a number of gases from soil. Canadian Journal Pure & Applied Sciences 8(2):2813-2824. Expand ABSTRACT

ABSTRACT: Addition of biochar to soils has the potentials to reduce the emission of greenhouse gases from soil. The primary objectives of this study were to see the impacts of biochar and the corresponding biomass application on the emission of carbon dioxide (CO2), carbon monoxide (CO), phosphine (PH3) and volatile organic compounds (VOCs) from soil investigated in a closed container experiment. Three replications of seven different treatments were applied: i) soil only (control), soil incorporated with – ii) rice husk, iii) biochar produced from rice husk, iv) straw, v) biochar from straw, vi) saw dust and vii) biochar produced from saw dust. The study reveals that addition of biochar had significant effects (P<0.05) on reducing CO2 and PH3 emission while no statistically significant effects on VOCs emanation was evident. Application of biochar could not suppress the CO emissions. Our study indicates that, different types of biochars have different effects on the emission of different gases.

Studies In Progress Using Akha TLUD Biochar

“Biochar for Food Security, Livelihood and Combating Climate Change”

A seminar held at the Bangladesh Agricultural Research Council, Dhaka, July 2018.
Abstracts of  Oral Papers

Download Seminar Proceedings (PDF, 1.6 Mb): summaries of the presentations, and a list of participants.

Haque, Md. Mojammel; Morshed, Md. Monjur; Alam, Mohammad Saiful; Kamal, Mohammed Zia Uddin; Rahman, G,K,M, Mustafizur; Rahman, Md. Mizanur. 2018. Impact of Biochar on Soil Fertility and Crop Productivity in Shibalaya Upazila of Manikganj District. Department of Soil Science, Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur, Bangladesh. Expand ABSTRACT

    ABSTRACT: An experiment in collaboration with Christian Commission for Development in Bangladesh was conducted at the farmer’s field in Shibalaya Upazila of Manikganj district during June 2017 to June 2018 using four vegetables (brinjal, tomato, cauliflower and chilli) to study the comparative effectiveness of different rates of biochar and recommended inorganic fertilizer on crop yields and soil fertility.  There were five treatments viz. control, recommended fertilizer (RF), biochar 1 t ha-1 + RF, biochar 3 t ha-1 + RF and biochar 5 t ha-1 + RF laid out in a randomized complete block design with three replications. The pH and moisture contents of the study soils were increased and bulk density decreased with the application of higher rate of biochar in all crops. Most incredible changes were observed in the total organic carbon contents in soils where carbon contents were increased by 25 to 33% from the initial levels. The highest yields of brinjal, tomato, cauliflower and chilli were found 67, 74, 42 & 4.5 t ha-1, respectively when biochar was applied @ 5 t ha-1 along with inorganic fertilizers. In terms of soil fertility and crop productivity application of biochar @ 5 t ha-1 was found promising and could be recommended as an effective soil management practice.

Hasnat, Momtahina; Rahman, Md. Mizanur; Rahman, GKM Mustafizur; Haque, Md. Manjurul. 2018. Role of Nitrogen Fertilizer on Mineralization of Organic Materials. Department of Soil Science & Department of Environmental Science Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh. Expand ABSTRACT

    ABSTRACT: Studies on the effect of nitrogen (N) fertilizer in organic materials mineralization and carbon (C) sequestration in soil are scarce. Therefore, this study quantified the release of C and N and determine the C degradation rate constant (k) of crop residues, compost and biochars as influenced by different levels of N fertilizer in a laboratory experiment during 22 November 2016 to 22 May 2017. The experiment comprising two factors viz. six types of organic materials (rice straw, maize leaf, rice husk biochar, eucalyptus biochar, mahogany biochar and vermicompost) and three rates of N fertilizer (0, 0.05 and 0.10 g N kg-1 soil) was laid out in a factorial RCBD with two replications. Rice husk biochar was prepared in BSMRAU, while eucalyptus and mahogany biochars were provided by CCDB, Manikganj produced as by-product from Akha cooking stove in local farm households.Organic materials considering 2.5 g C kg-1 soil and N fertilizer were mixed well and placed in pots for six incubation periods of 30, 60, 90, 120, 150 and 180 days. The trend of organic carbon contents was decreasing order with irregular fashion until 180 days of incubation in all types of treatments and the lowest C content was found at 180 days of incubation. Under different level of N application, OC contents finally reached lowest level at 180 days of incubation. During 180 days of incubation the highest amount of OC was observed in 0 g N kg-1 soil (1.28%) and the lowest in 0.1g N kg-1 soil (1.06%). Carbon degradation rate constants (k) of different organic materials in the present study varied from 0.00502 to 0.00635 day-1. The lowest ‘k’ value was found in the mahogany biochar applied soil, while the highest was under the rice husk biochar used soil. The highest k value was found in the 0.1 g N kg-1 soil (0.00607), while the lowest was in the 0 g N kg-1 soil (0.00549). The relationship between ‘k’ value and mineralization is reciprocal i.e. the higher the k value the slower is the mineralization of organic material. Organic carbon contents in soils decreased with the advancement of incubation periods and higher N rates. Nitrate and ammonium nitrogen contents found higher in soils at 60-90 days of incubation under higher N rates. The lowest ‘k’ value attributed in the mahogany biochar followed by maize leaf, vermicompost, rice straw, eucalyptus biochar and rice husk biochar. Higher N rates resulted lower ‘k’ value and contributed to faster mineralization of organic materials. Rice husk and eucalyptus biochars along with optimum N fertilizer needs to be ensured in crop production which could limit mineralization and supply long lasting and stable carbon in soil.

Murad, K.F.I.; Alam, M.K.; Alam M.J.; Sabuz, A.A. 2018. Potentiality of Biochar to Enhance Productivity of Tomato Cultivated under Deficit Irrigation. Bangladesh Agricultural Research Institute (BARI). Expand ABSTRACT

    ABSTRACT: This study was conducted at the research field of Irrigation and water Management Division (IWM) of Bangladesh Agricultural Research Institute (BARI), Gazipur to understand the potentiality of biochar in improving productivity of drip irrigated tomato cultivated under deficit irrigation condition, and its impacts on some soil properties. BARI Tomato-14 cultivar was used for this experiment. There were five different irrigation treatments; T1: full irrigation (FI) with biochar @10 t/ha; T2: deficit irrigation (75% of FI) with biochar; T3: deficit irrigation (50% of FI) with biochar; T4: FI with no biochar; T5: 75% of FI with no biochar; T6: 50% of FI with no biochar. The experiment is laid out in a Randomized Complete Block Design (RCBD), where each treatment was replicated thrice. Biochar was produced by Akha (krishi bandob chula) using different biomass from working area of Christian Commission for development in Bangladesh (CCDB). Data on different growth and yield attributes of tomato were collected during the crop growing season and after harvesting. Necessary soil data were also collected periodically to determine the soil-moisture content, available nitrogen (N) status as well as the microbial-respiration of soil during the experimental period. The obtained result suggests that deficit irrigation reduced the plant height (highest in full irrigation > 75% irrigation > lowest in 50% irrigation); whereas, biochar application improved the plant heights (T1>T4, T2>T5 and T3>T6). The number of branches per plant did not show statistically significant difference among the irrigation treatments. In contrast to the plant height, root length was found higher in non-biochar treatments (T4, T5, T6) than that of their opposite biochar treatments (T1, T2, T3), where it increased as the water deficiency increased (T1<T2<T3 or T4<T5<T6). Again, both wet biomass and dry biomass weight was found highest in T1, where the lowest values of both attributes were found in T6. On the other hand, the number of fruit per plant, unit fruit weight and marketable yield were found highest in T1 followed by T4, T2, T3, T5 and T6. A significant yield reduction of about 5.6% and 10.5% between T1 and T3, T4 and T6, respectively suggests that irrigation deficiency (by 50%) significantly reduced the production of tomato. Moreover, the marketable yield of T1>T4 (3.7%), T2>T5 (6.0%) and T3>T6 (7.9%) illustrates that biochar potentially increased the crop production, and it showed better performance when the irrigation deficiency increased. In addition, water productivity (WP) was found 5.5% higher in T1 than T4, 10.2% higher in T2 than T5, and 10.6% higher in T3 than T6. Soil moisture content dropped sharply in non-biochar treatments under deficit irrigation; however, biochar improved the moisture content status under the similar circumstances. The hetero-tropic respiration (CO2 emission) were found higher in biochar amended treatment, where it was recorded highest in T2 and lowest in T6. Biochar with FI (T1) had the highest available NH4-N over the season followed by biochar with 75 % FI (T2). But, available NO3-N was highest in T2, while T6 had the lowest value. No significant variation on the fruit quality parameters were found between these two treatments. While carotenoids and total soluble solids (TSS) were also found slightly higher in biochar amended treatment (T1), both Vitamin-C and Tritable acidity contents were marginally higher in treatment without biochar (T4). Overall, biochar found to be promising in improving the growth and yield of tomato grown under deficit irrigation regimes, as well as the health of the soil. However, no discreet conclusion can be drawn unless the research is replicated for few more years.

Sen, Ranjit; Masud, M. M.; Islam, Md. Mahbubul; Ferdous, Janatul. 2018. Biochar Production by Akha and its Impact on Productivity of Tomato, Maize, Okra and Chili Grown in Acid Soil. Bangladesh Agricultural Research Institute & Christian Commission for Development in Bangladesh. Expand ABSTRACT

    ABSTRACT: Pyrolysis is the most common technology employed to produce biochar, and also occurs in the early stages of the combustion and gasification processes. Different types of biochar making device produced under zero-oxygen conditions or oxygen limiting condition but costs associated with logistics and opportunity costs from diversion from energy or an active form in soil demand certainty and predictability of the agronomic return. Practical biochar making effective low-cost technology called AKHA (agriculture friendly cook stove) developed by the Bangladesh Biochar Initiative (BBI) foster by Christian Commission for Development in Bangladesh (CCDB), its ability to make biochar at the same time as cooking. In the present study, a pot experiment was conducted in Manda, Daudpur and Shivalaya CCDB office to study the effect of biochar (produce from AKHA) on the productivity of Tomato and Maize in Rabi season and Chilli and Okra in Kharif season of 2016-2017. There were three biochar levels, viz., 10g/ kg soil, 20g/ kg soil and 10% of pot soil volume. Plant development in the biochar-treated pots was significantly enhanced as compared with the un-amended controls where 100% recommended fertilizer had been used for respective crops. The incorporation of biochars produced from different wood source increased the soil pH, and their ameliorating effects varied due to raw materials of biochars. The results on the growth and yield parameters of the tomato showed that the biochar had the significant effect on plant height, number of fruit, length and breadth of fruit, individual fruit weight and fresh yield. Among the three wood mix biochar levels, biochar @ 20 g/kg soil showed the better performance and increased soil nutrients of Ca, Mg and K, but also enhanced the uptake of Ca, Mg, K and P by plants simultaneously.
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