Differences in Biochar Sources for Controlled Nitrogen Loss in a Hybrid Maize Agroforestry System with Melaleuca cajuputi

Background: The main problem in nitrogen fertilization for crop cultivated is the very low efficiency due to the leaching process. The purpose of this study was to the determination of the optimum levels of biochar amendment made from Melaleuca cajuputi biochar (MCB) and urea fertilizer (UF) for nitrogen use efficiency in upland rice under M. cajuputi stands.Methods: The study was conducted during dry season within March to June 2019 in Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District, Indonesia. The experimental design was laid out in a randomized complete block design factorial with three replications as the response surface methodology (RSM). The treatments consisted of MCB levels (0, 5, 10, 15 tons ha-1) and UF levels (0, 100, 200, 300 kg ha-1) as independent variables. The observation parameters were nitrate reductase activity (NRA), total chlorophyll (TC), leaf photosynthesis rate (LPR), nitrogen loss (NL), nitrogen use efficiency (NUE) and seed yield (SY). The data was analyzed using RSM approach and ridge regression.Result: The optimizing applications of 11.14 tons ha-1 of MCB and 281.13 kg ha-1 of UF resulted in NUE and SY by 2.14 kg grain kg Nfertilizer-1 and 5.83 tons ha-1 or increased by 19.07% and 13.02%, compared to a single application of UF by 300 kg ha-1.

Background: Nutrient briquette and biochar are used to reduce nitrogen loss and improve soil fertility. This study aimed to evaluate the interaction of biochar briquette with ammonium sulfate fertilizer for controlled nitrogen loss in soybean intercropping with Melaleuca cajuputi. Methods: The study was conducted in the wet season from November to February 2020 at Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District, Indonesia. The experiment was using a randomized complete block design factorial with three blocks as the response surface methodology. The treatments included different levels of biochar briquette from Melaleuca cajuputi waste (0, 2 and 4 grain plant-1 or 0, 5 and 10 tons ha-1) and nitrogen fertilizer supplied by ammonium sulfate (0, 50 and 100 kg ha-1) as independent variables. The observation parameters were nitrate reductase activity (NRA), total chlorophyll (TC), leaf photosynthesis rate (LPR), nitrogen loss (NL), nitrogen use efficiency (NUE) and seed yield (SY). Result: The optimum values of 3.70 grain plant-1 or 9.25 tons ha-1 biochar briquette with 76.31 kg ha-1 ammonium sulfate fertilizer decreased NL by 38.25% and increased SY by 13.02% compared with single ammonium sulfate fertilizer.

Background: Biochar has a function for soil amendment and leaching loss for nitrogen fertilizer. The objectives of this study was to evaluate the effectiveness of Melaleuca cajuputi biochar as a leaching loss for nitrogen fertilizer and intercropping in maize. Methods: The study was conducted from February to June 2019 in Menggoran Forest Resort, Playen District, Gunungkidul Regency, Special Province of Yogyakarta, Indonesia. The experimental design was a randomized complete block design (RCBD) factorial with three replications as the response surface methodology (RSM). The treatments consisted of biochar levels made from Melaleuca cajuputi waste (0, 5, 10, 15 tons ha-1) and nitrogen fertilizer levels sourced from urea (0, 150, 300 kg ha-1) as independent variables. The observation parameters were nitrate reductase activity (NRA), total chlorophyll (TC), net photosynthesis (NP), nitrogen loss (NL), nitrogen use efficiency (NUE) and seed yield per hectare (SY). Result: The RSM revealed that the optimum value of 13.290 tons ha-1 of Melaleuca cajuputi biochar (MCB) and 245.350 kg ha-1 of nitrogen fertilizer (NF) can reduced urea by 18.22%. This recommendation increased NRA, TC, NP, NL, NUE and SY by 35.28%, 19.55%, 18.09%, -46.81%, 27.96% and 61.78%, respectively, in compare to the single application of urea.

This study investigated the removal of heavy metal ions from industrial wastewater by using rice and corn husk biochar. The choice of the materials was influenced by their large surface area, abundance of functional groups as well as their availability in the local environment. Rice and corn husks were pyrolyzed at 500, 600, and 700 °C to make biochars that were used to treat low-quality industrial wastewater. Initial metal ion levels in wastewater and residual levels after the application of biochars were measured using an atomic adsorption spectrophotometer. Carbonization of rice husks at 600 °C produced the best removal efficiencies for Cr (65%), Fe (90%), and Pb (> 90%). The carbonization of corn husks at 600 °C produced the worst removal efficiencies for Cr (only 20%) and Pb (slightly > 35%). Regardless of the carbonization temperature, rice husk biochars performed better than corn husk biochars. Experimental data fitted well the Langmuir and Freundlich isotherm models (R2 values ranging between 0.82 and 0.99). The Langmuir separation factor, RL, had negative values, probably due to the low initial concentration of the adsorbates in the raw wastewater. All the biochars showed a relatively short contact time (20 to 30 min) to attain maximum adsorption efficiencies and are a promising feature for future industrial applications. The studied biochar materials from rice and corn husk have the potential to remove heavy metal ions from industrial wastewater; rice husk biochar showed higher removal capacity than corn husk biochars.

Background: Biochar is a promising material in mitigating greenhouse gases (GHGs) emissions from paddy fields due to its remarkable structural properties. Rice husk biochar (RhB) and melaleuca biochar (MB) are amendment materials that could be used to potentially reduce emissions in the Vietnamese Mekong Delta (VMD). However, their effects on CH 4 and N 2O emissions and soil under local water management and conventional rice cultivation have not been thoroughly investigated. Methods: We conducted a field experiment using biochar additions to the topsoil layer (0-20 cm). Five treatments comprising 0 t ha -1 (CT0); 5 t ha -1 (RhB5) and 10 t ha -1 (RhB10), and 5 t ha -1 (MB5) and 10 t ha -1 (MB10) were designed plot-by-plot (20 m 2) in triplicates. Results: The results showed that biochar application from 5 to 10 t ha -1 significantly decreased cumulative CH 4 (24.2-28.0%, RhB; 22.0-14.1%, MB) and N 2O (25.6-41.0%, RhB; 38.4-56.4%, MB) fluxes without a reduction in grain yield. Increasing the biochar application rate further did not decrease significantly total CH 4 and N 2O fluxes but was seen to significantly reduce the global warming potential (GWP) and yield-scale GWP in the RhB treatments. Biochar application improved soil Eh but had no effects on soil pH. Whereas CH 4 flux correlated negatively with soil Eh ( P <0.001; r 2 = 0.552, RhB; P <0.001; r 2 = 0.502, MB). Ameliorating soil aeration and functions by adding RhB and MB resulted in improving soil physicochemical properties, especially significant SOM and AN boosting, which indicate better soil health, structure, and fertility. Conclusions: Biochar supplementation significantly reduced CH 4 and N 2O fluxes and improved soil mineralization and physicochemical properties toward beneficial for rice plants. The results suggest that the optimal combination of biochar-application rates and effective water-irrigation techniques for soil types in the MD should be further studied in future works.

Background: Biochar is a promising material in mitigating greenhouse gases (GHGs) emissions from paddy fields due to its remarkable structural properties. Rice husk biochar (RhB) and melaleuca biochar (MB) are amendment materials that could be used to potentially reduce emissions in the Vietnamese Mekong Delta (VMD). However, their effects on CH 4 and N 2O emissions and soil under local water management and conventional rice cultivation have not been thoroughly investigated. Methods: We conducted a field experiment using biochar additions to the topsoil layer (0-20 cm). Five treatments comprising 0 t ha -1 (CT0); 5 t ha -1 (RhB5) and 10 t ha -1 (RhB10), and 5 t ha -1 (MB5) and 10 t ha -1 (MB10) were designed plot-by-plot (20 m 2) in triplicates. Results: The results showed that biochar application from 5 to 10 t ha -1 significantly decreased cumulative CH 4 (24.2-28.0%, RhB; 22.0-14.1%, MB) and N 2O (25.6-41.0%, RhB; 38.4–56.4%, MB) fluxes without a reduction in grain yield. Increasing the biochar application rate further did not decrease significantly total CH 4 and N 2O fluxes but was seen to significantly reduce the global warming potential (GWP) and yield-scale GWP in the RhB treatments. Biochar application improved soil Eh but had no effects on soil pH. Whereas CH 4 flux correlated negatively with soil Eh ( P < 0.001; r 2 = 0.552, RhB; P < 0.001; r 2 = 0.502, MB). Ameliorating soil aeration and functions by adding RhB and MB resulted in improving soil physicochemical properties, especially significant SOM and AN boosting, which indicate better soil health, structure, and fertility. Conclusions: Biochar supplementation significantly reduced CH 4 and N 2O fluxes and improved soil mineralization and physicochemical properties toward beneficial for rice plants. The results suggest that the optimal combination of biochar-application rates and effective water-irrigation techniques for soil types in the MD should be further studied in future works.

Background: Biochar is a promising material in mitigating greenhouse gases (GHGs) emissions from paddy fields due to its remarkable structural properties. Rice husk biochar (RhB) and melaleuca biochar (MB) are amendment materials that could be used to potentially reduce emissions in the Vietnamese Mekong Delta (VMD). However, their effects on CH 4 and N 2O emissions and soil under local water management and conventional rice cultivation have not been thoroughly investigated. Methods: We conducted a field experiment using biochar additions to the topsoil layer (0-20 cm). Five treatments comprising 0 t ha -1 (CT0); 5 t ha -1 (RhB5) and 10 t ha -1 (RhB10), and 5 t ha -1 (MB5) and 10 t ha -1 (MB10) were designed plot-by-plot (20 m 2) in triplicates. Results: The results showed that biochar application from 5 to 10 t ha -1 significantly decreased cumulative CH 4 (24.2 - 28.0%, RhB; 22.0 - 14.1%, MB) and N 2O (25.6 - 41.0%, RhB; 38.4 - 56.4%, MB) fluxes without a reduction in grain yield. Increasing the biochar application rate further did not decrease significantly total CH 4 and N 2O fluxes but was seen to significantly reduce the global warming potential (GWP) and yield-scale GWP in the RhB treatments. Biochar application improved soil Eh but had no effects on soil pH. Whereas CH 4 flux correlated negatively with soil Eh ( P < 0.001; r 2 = 0.552, RhB; P < 0.001; r 2 = 0.502, MB). The soil physicochemical properties of bulk density, porosity, organic matter, and anaerobically mineralized N were significantly improved in biochar-amended treatments, while available P also slightly increased. Conclusions: Biochar supplementation significantly reduced CH 4 and N 2O fluxes and improved soil mineralization and physiochemical properties toward beneficial for rice plant. The results suggest that the optimal combination of biochar-application rates and effective water-irrigation techniques for soil types in the MD should be further studied in future works.

Vertisol is a type of soil whose mineral fraction is dominated by 2:1 type clay minerals (smectite) which have the property of swelling-shrinking periodically as the soil water content changes. However, these physical properties can be improved by the application of biochar so that it can support plant growth. The aim of this study was to evaluate the effect of biochar on changes in the physical characteristics of vertisols soils and growth performance of soybean plants. This research was conducted in Kawo Village, Pujut District, Central Lombok. This study was designed to test the application of two types of biochar, namely rice husk biochar (BS) and corn cob biochar (BJ) at several doses, namely 0, 15, 30 and 60 g/kg of vertisols soil and design using a randomized block design with 6 replications. The parameters measured were unit weight, soil density, porosity, soil tensile strength, available water capacity, aggregate stability, cole value, crack pattern and soybean growth test. The results showed that the application of biochar could improve the physical properties of vertisol soil and also has implications for improving the growth of soybean plants. Observational data showed that a dose of 60 g/kg of biochar, both rice husk and corn cob biochar, showed better changes in soil physical properties compared to biochar doses of 15 g/kg, 30 g/kg and without the addition of biochar. Besides that, the treatment of rice husk and corn cob biochar at a dose of 60 g/kg gave better vegetative growth of soybean plants.

ABSTRACTLegumes, including hairy vetch (Vicia villosa Roth), are widely used as green manures. They fix nitrogen (N) and provide the N to other crops when they decompose, and thus are considered alternatives for chemical N fertilizers. However, N-rich plant residues, including hairy vetch, are also sources of soil nitrous oxide (N2O) emissions, a greenhouse gas. On one hand, rice (Oryza sativa L. ssp. japonica) husk biochar is widely used as a soil conditioner in Japan and has been reported as a tool to mitigate soil N2O emissions. We conducted a soil core incubation experiment (1.5 months) to compare the N2O emissions during the decomposition of surface-applied hairy vetch (0.8 kg dried hairy vetch m−2 soil) under semi-saturated soil moisture conditions (~100% water-filled pore space (WFPS)), using two soil types, namely Andosol and Fluvisol. Throughout the incubation period, the use of biochar suppressed soil NH4+-N concentrations in Andosol, whereas the effect of biochar on NH4+-N was not clear in Fluvisol. Biochar increased the nitrate (NO3−-N) levels both in Andosol and Fluvisol, suggesting a negative influence on denitrification and/or a positive influence on nitrification. Biochar application did not influence the cumulative N2O emissions. Our study suggests that rice husk biochar is not a good option to mitigate N2O emissions during the decomposition of surface-applied hairy vetch, although this study was performed under laboratory conditions without plants. However, the trends of the inorganic-N concentration changes followed by the addition of hairy vetch and biochar were markedly different between the two soil types. Thus, factors behind the differences need to be further studied.

Effect of rice straw and husk biochar on vegetative growth and yield attributes of Oryza sativa L Singanayagam Thavanesan1*, Thayamini H. Seran2 1 Department of Crop Science, Faculty of Agriculture, Eastern University, Chenkalady, Sri Lanka 2 Department of Crop Science, Faculty of Agriculture, Eastern University, Chenkalady, Sri Lanka Abstract: A research was conducted to evaluate the growth and yield of rice as influenced by rich straw and husk biochar along with chemical fertilizer. The experiment was done with six treatments. T1- recommended chemical fertilizer, T2- Rice straw (1.0 t/ha), T3-Rice husk biochar (1.0 t/ha), T4-Rice straw (0.5 t/ha) + Rice husk biochar (0.5 t/ha), T5-Rice straw (1.0 t/ha) + Rice husk biochar (0.5 t/ha) and T6-Rice straw (1.0 t/ha) + Rice husk biochar (1.0 t/ha). Recommended chemical fertilizer was incorporated to all the treatments. During the vegetative periods, the growth parameters were recorded and finally yield analysis was done. Rice plants treated in rice straw (1.0 t/ha) and husk biochar (1.0 t/ha) along with chemical fertilizer had significantly (P&amp;lt;0.05) higher mean values of leaf area (185.93 cm2), number of tillers (4.0), number of roots per plant (105.33) and also dry weights of shoots (5.15 g) and roots (4.27 g) per plant when comparing chemical fertilizer alone. Average number of grains (187.67), number of filled grains (170.33) and filled grain weight per panicle (3.142 g) was also considerably increased in rice straw (1.0 t/ha) and husk biochar (1.0 t/ha) treatment followed by husk biochar (1.0 t/ha) treatment than those in the control. There were no significant difference (P&amp;gt;0.05) in 100 seed weight between them. Hence, it can be concluded that addition of rice straw (1.0 t/ha) and husk biochar (1.0 t/ha) along with chemical fertilizer to rice field is feasible to increase the grain yield under local conditions. Key words: Biochar, Rice straw, Rice husk, Rice, Seed weight [*] Corresponding author: thayaminis@esn.ac.lk, thayasean@yahoo.com

The use of biochar to improve soil properties and decrease the leaching of nutrients has received attention, yet very little research has focused on its effects on Calcaric Cambisols. We evaluated the effect of rice (Oryza sativa L.) husk biochar at the highest pyrolysis temperatures of 450°C and 650°C (RH450 and RH650) on nutrient leaching, nutrient availability, and microbial properties of Calcaric Cambisols in the karst region of southwestern China. In a soil column leaching experiment, rice husk biochars produced under two temperatures were added at 1%, 2%, and 5% (weight/weight) to Calcaric Cambisols following application of fertilizer (ammonium nitrate [NH4NO3] and monopotassium phosphate [KH2PO4]) and incubated for 28 weeks. A control treatment (without rice husk biochar) was also included. After a 28-week incubation, both temperature rice husk biochars significantly reduced the cumulative amounts of ammonium (NH4+) in leachate from Calcaric Cambisols, while they increased cumulative amounts of leachate phosphate (PO43−) and potassium (K+). Addition of 2% and 5% RH650 significantly reduced cumulative amounts of leachate nitrate (NO3−), while RH450 amendment had no significant influence on NO3−-N leaching. Addition of 5% RH450 significantly increased soil available nitrogen (N) content simultaneously accompanied by a significant increase in microbial biomass N, suggesting net N mineralization was enhanced and soil microorganisms utilized a portion of mineral N for their own cell building. Both temperature rice husk biochar additions caused a significant increase in soil available phosphorus (P) and K. The highest P availability was observed in RH450-treated soil samples at 5% rate. Compared with RH450 treatment, higher K availability was found in RH650-treated soils. Both rice husk biochar additions significantly increased soil microbial biomass carbon (C), and RH450 addition also significantly increased soil microbial biomass P and soil fluorescein diacetate activity (FDA). This is largely due to the more labile C in RH450 (high oxygen [O]/C and hydrogen [H]/C ratios). The results suggest that high-temperature rice husk biochar amendment may be an effective strategy for reducing N leaching of Calcaric Cambisols, whereas low-temperature rice husk biochar has more beneficial effect on soil microbial biomass and microbial activity.

Declining soil fertility and the limited use of sustainable soil organic amendments has resulted in reduced crop productivity in Nepal. This study assessed biochar produced from rice husk and sawdust at three different pyrolysis temperatures (200°C, 400°C, and 600°C), characterized their properties and applied them as soil amendments to test their agronomic effect on kidney bean production. The highest biochar yields were achieved at lower pyrolysis temperatures (200°C) for both rice husk (40%) and sawdust (38.4%). Ash content was significantly higher in rice husk (33.6%) compared to sawdust biochar (5.8%) across all temperatures. Sawdust biochar had higher volatile matter (91%) than in rice husk biochar (61.5%). The fixed carbon content was greater at 200°C and 400°C for both rice husk and sawdust biochar. FT-IR result showed significant loss of aromatic groups with increasing temperature. Biochar from all three temperatures was then used in a pot experiment to grow kidney beans and assess their agronomic effects. Seven treatments were used: control (CK), rice husk biochar at 200°C (RH200), 400°C (RH400), and 600°C (RH600), sawdust at 200°C (SD200), 400°C (SD400), and 600°C (SD600) following a completely randomized design with 3 replications per treatment. Cattle manure was applied uniformly (25 t ha-1) across all treatments, including the control. Over 50 days, SD400 resulted in the tallest plants, SD600 produced the thickest stem and RH600 had the highest number of leaves. Biochar applications showed significantly higher fruit weight and counts, which was on average 24 % higher than the control, with no significant differences between rice husk and saw dust biochar at three different temperatures. The study suggests that high quality biochar can be produced from both rice husk and saw dust and its application boost legume yields, which is crucial for enhancing country’s nutritional and food security.

Heavy metal contamination was an environmental and human health problem all over the world. Cadmium is the most hazardous heavy metals due to its high mobility and toxicity at low concentrations. Lead (Pb) also belongs to the hazard element caused by its prolonged persistence in the soil. This study aimed to develop the remediation techniques on polluted land, i.e. a combination of biochar and indigenous plant. The biochar was produced by slow pyrolysis method. This experiment was conducted at the farmland at Sumber Brantas, Malang, East Java. We used rice husk and tobacco waste biochar, and Eleusine indica (L.) Gaertn and Rorippa sylvestris (L.) Bess. as remediator plants. The results showed that rice husk biochar had a significant effect on pH value and potassium content (p = 0.0001; p=0.0004). On the contrary, the soil nitrogen content, soil organic-C content, and soil cation exchange capacity applied with tobacco waste biochar application were higher than that applied with rice husk biochar (p = 0.03; p=0.00001; p = 0.00001). The improvement of soil characteristics increased the growth of Eleusine indica and Rorippa sylvestris as indicated by the plant height and biomass. The addition of biochar could promote the growth of remediator plant and enhanced the accumulation of Pb and Cd in the plants. Mixtures of rice husk biochar and tobacco waste biochar caused Eleusine indica more effectively absorbed heavy metals than Rorippa sylvestris on all types of biochar treatments; Eleusine indica absorbed Pb and Cd higher than Rorippa sylvestris as shown by Pb and Cd contents in the soil.

The effects of biochars produced in different pyrolsis temperatures from agricultural wastes on cadmium uptake of tobacco plant

This study aims to evaluate the effect of rice husk and coffee husk biochar, evaluate difference effect of rice and coffee husk biochar and to know the effect of difference of dose of rice and coffee husk biochar phosphate and zinc, and rice growth in the paddys soil with high total P . The research was conducted on the greenhouse, Faculty of Agriculture, University of North Sumatra, Medan. The soil which used from the paddys soil in Lubuk Dendang, Perbaungan, Serdang Bedagai which has the high total P. The experiment was carried out using completely randomized design with 7 treatment : control ; 10 tons/ha, 20 tons/ha, and 30 tons/ha rice husk biochar ; 10 tons/ha, 20 tons/ha, and 30 tons/ha coffee husk biochar. The Analysis of data used the analysis of variance and contrast orthogonal test.