scholarly journals Effect of pyrolysis temperature on Si release of alkali-enhanced Si-rich biochar and plant response

Biochar ◽  
2021 ◽  
Author(s):  
Meng Wang ◽  
Negar D. Tafti ◽  
Jim J. Wang ◽  
Xudong Wang
Keyword(s):  
Rice Straw ◽  
Rice Husk ◽  
Pyrolysis Temperature ◽  
Weak Acid ◽  
Rice Grain ◽  
Neutral Salt ◽  
Salt Solutions ◽  
Plant Disease Control ◽  
Si Content ◽  
Lower Temperature

AbstractRecent studies have shown that silicon (Si) dissolution from biochar may be influenced by the pyrolysis temperature. In addition, the enhancement of biochar by treatment with alkali has been proposed to produce a Si source that can be used for environmentally friendly plant disease control. In this study, biochars from rice straw and rice husk pretreated with KOH, CaO and K2CO3 and then pyrolyzed at 350, 450 and 550 °C were prepared to evaluate the effects of pyrolysis temperature on Si release and plant uptake from alkali-enhanced Si-rich biochar. Extractable Si and dissolution Si from the prepared biochars were assessed by different short-term chemical methods and long-term (30-day) release in dilute acid and neutral salt solutions, respectively, along with a rice potting experiment in greenhouse. For both rice straw- and husk-derived alkali-enhanced biochars (RS-10KB and HS-10K2B, respectively), increasing the pyrolysis temperature from 350 to 550 °C generally had the highest extractable Si and increased Si content extracted by 5-day sodium carbonate and ammonium nitrate (5dSCAN) designated for fertilizer Si by 61–142%, whereas non-enhanced biochars had more extractable Si at 350 °C. The alkali-enhanced biochars produced at 550 °C pyrolysis temperature also released 82–172% and 27–79% more Si than that of 350 °C produced biochar in unbuffered weak acid and neutral salt solutions, respectively, over 30 days. In addition, alkali-enhanced biochars, especially that derived from rice husk at 550 °C facilitated 6–21% greater Si uptake by rice and 44–101% higher rice grain yields than lower temperature biochars, non-enhanced biochars, or conventional Si fertilizers (wollastonite and silicate calcium slag). Overall, this study demonstrated that 550 °C is more efficient than lower pyrolysis temperature for preparing alkali-enhanced biochar to improve Si release for plant growth.

scholarly journals Effects of Rice Husk Biochar Coated Urea and Anaerobically Digested Rice Straw Compost on the Soil Fertility, and Cyclic Effect of Phosphorus

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 75
Author(s):  
Ashoka Gamage ◽  
Ben Basnayake ◽  
Janendra De Costa ◽  
Othmane Merah
Keyword(s):  
Soil Fertility ◽  
Rice Straw ◽  
Rice Husk ◽  
Nitrogen Fertilizer ◽  
Fertilizer Application ◽  
Rice Grain ◽  
Coated Urea ◽  
Rice Husk Biochar ◽  
High Yielding Varieties ◽  
Coated Fertilizers

Fertilizer application in rice farming is an essential requirement. Most of the high-yielding varieties which are extensively grown throughout the country require recommended levels of fertilizers to obtain their potential yields. However, effective, and efficient ways of fertilizer application are of utmost importance. Coated fertilizers are used to reduce leaching nutrients and improve the efficiency of fertilizer. However, conventional coated fertilizers such as Sulphur coated urea and urea super granules are not popular among rice farmers in Sri Lanka owing to the high cost. Mixing urea-coated rice husk biochar causes a slow release of nitrogen fertilizer. This coated fertilizer and rice straw compost reduction the cost of importations of nitrogen-based fertilizers per unit area of cultivation. The study aimed to evaluate the effects of rice husk biochar coated urea and anaerobically digested rice straw compost on the soil fertility, and the cyclic effect of phosphorus. Concerning the pot experiment, rice grain yield was significantly higher in Rice husk biochar coated urea, triple super phosphate (TSP), and muriate of potash (MOP) with anaerobically digested rice straw compost. The lowest yield was observed in the control. The release of phosphate shows a cycle effect which is an important finding. Rice husk biochar coated urea can potentially be used as a slow-releasing nitrogen fertilizer. In addition, the urea coated with biochar is less costly and contributes to mitigating pollution of water bodies by inorganic fertilizers (NPK).

scholarly journals Kinetic and Equilibrium Studies on the Zinc Adsorption-desorption Characteristics of Some Promising Biochars in Aqueous Solutions

2021 ◽  
Author(s):  
Masoumeh Faryadi Shahgoli ◽  
Adel Reyhanitabar ◽  
Nosratollah Najafi ◽  
Shahin Oustan
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Rice Straw ◽  
Pyrolysis Temperature ◽  
Ph Effect ◽  
Solution Ph ◽  
Equilibrium Studies ◽  
Batch Technique ◽  
Adsorption Desorption ◽  
Zinc Adsorption

Abstract The present research aimed at investigating zinc (Zn) sorption capacity of the biochars derived from apple wood (WB) and rice straw (RB) feedstocks at two 300 and 600°C pyrolysis temperatures (WB300, WB600, RB300 and RB600, respectively) in aqueous solutions. Kinetic and equilibrium sorption experiments were conducted via batch technique. In equilibrium adsorption experiments, the study used the concentration range of 5-200 mg Zn L− 1 and focused on the solution pH effect on Zn adsorption in biochars under the following conditions: unadjusted and adjusted pH (4 and 6) and three ionic strength levels (0.01, 0.03, 0.1 M KNO3). Zinc desorption experiments were conducted under all above mentioned conditions but without pH adjustment at five separate stages. Kinetic data analysis indicated that Zn adsorption in biochars reached the near steady state within 24 hours with the sorption rate order of WB300 < WB600 < RB300 < RB600. The best fitness was superior to both Elovich and exponential rate models. Also, Zn adsorption isotherms in the studied biochars were shown to fit quite well to Langmuir, Freundlich and Dubinin-Radushkevich models. Zn sorption maxima were found to be 4.3, 16.4, 17.9 and 33.3 mg g− 1, on average, for WB300, WB600, RB300, and RB600, respectively. The initial increased pH solution from 4 to 6 caused an increase in Zn adsorption in RB600, RB300 and WB600, however the sorption maxima in WB300 was detected at pH 4. The rise in solution ionic strength from 0.01 M to 0.1 M dropped the Zn adsorption capacity in all the studied biochars. Findings suggested that rice straw derived biochars showed a better performance than woody biochars in Zn sorption and retention from aqueous solutions. In addition, this ability increased with increasing pyrolysis temperature in both types of biochars. Finally, the study revealed that rice straw biochars, produced at high pyrolysis temperatures, can serve as economical and efficient absorbents for Zn removal from aqueous solutions.

scholarly journals Manurial amendments and source of water for supplemental irrigation of sawah-rice system influenced soil quality and rice yield

Agro-Science ◽  
2021 ◽  
Vol 20 (1) ◽  
pp. 95-102
Author(s):  
A.L. Nnadi ◽  
V.U. Ugwu ◽  
J.C. Nwite ◽  
S.E. Obalum ◽  
C.A. Igwe ◽  
...  
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Spring Water ◽  
Mineral Fertilizers ◽  
Small Scale ◽  
Rice Grain ◽  
Southeastern Nigeria ◽  
Supplemental Irrigation ◽  
Husk Rice ◽  
Poultry Droppings

Soil and water management research on adapting the promising sawah ecotechnology for lowland rice farming in West Africa has largely focused on the abundant inland valleys; floodplains which too represent a huge agricultural resource in the region have not been so involved. Sawah refers to a bunded, puddled and leveled basin for rice, with water inlets and outlets for irrigation and drainage, respectively. In conventional sawah, soil fertility is augmented using mineral fertilizers, with an option to harness lowland water resources for use in small-scale irrigation to create the so-called sawah typologies. In this study, we evaluated the effects of three manurial amendments (rice husk, rice-husk ash and poultry droppings, each at 10 t ha–1) and NPK 20:10:10 at 400 kg ha–1 interacting with source of water (spring or pond) used for supplemental irrigation of three sawah typologies in a floodplain in southeastern Nigeria. Plots amended with poultry droppings and supplemented with spring water recorded the overall best performance of the sawah-rice system; the control being the unamended non-supplemented (solely rainfed) plots recorded the worst. Rice-husk ash and rice husk enhanced soil pH and soil organic carbon, respectively. The three sawah typologies showed a consistent trend thus spring-supplemented ≥ pond-supplemented ≥ non-supplemented sawah. Rice grain yield was influenced by soil total nitrogen and the sum of the three plant-nutrient basic cations (K+ , Ca2+ and Mg2+), with the influence of K+ alone being the greatest. To enhance rice performance including grain yields in floodplain sawah, farmers should utilise poultry droppings as soil manure and spring water for supplemental irrigation.

scholarly journals Karakterisasi Bionanofiller Dari Limbah Padi Sebagai Alternatif Penguatan Pada Polimer Komposit

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Eryani . ◽  
Sri Aprilia ◽  
Farid Mulana
Keyword(s):  
Rice Straw ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Particle Density ◽  
Agricultural Waste ◽  
Xrd Analysis ◽  
Silica Content ◽  
Sem Analysis ◽  
Agricultural Produce ◽  
Mechanical Properties Characterization

<p>Agricultural waste such as rice straw, rice husk and rice husk ash have not been utilized properly. This waste of agricultural produce can actually be used as an alternative to bionanofiller because it contains an excellent source of silica. The silica content contained in the rice waste when combined with the polymer matrix can produce composites having high thermal and mechanical properties. Characterization of bionanofiller from this rice waste is done by SEM, XRF, FTIR, XRD and particle density. The result of SEM analysis from this rice waste is feasible to be used as filler because it has size 1 μm. Likewise with the results of XRF analysis that rice waste contains a high enough silica component that is 80.6255% - 89.83%. FTIR test results also show that bionanoparticles from rice waste have the same content of silica. In the XRD analysis the best selective gain of rice waste is found in rice husk ash which is characteristic of amorp silica at a range of 2ϴ = 22<br />. The largest density analysis of paddy waste was found in rice husk 0.0419 gr / cm , followed by rice straw by of 0.0417 gr / cm 3 and rice hulk ash 0.0407 g / cm 3</p>

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