scholarly journals PREPARATION, CHARACTERIZATION OF BIOCHAR FOR A SUSTAINABLE SOIL HEALTH

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rekha A. ◽  
Vidhya A.

Recent research suggests that biochar is a promising approach to minimize soil contamination caused by heavy metals and organic pollutants. It is also involved in the amendment of soil by altering the nutrients, pH and other factors. Through intensive literature review, this paper was aimed to better understand the selection of feedstock processes, preparation, and characterization of biochar. Wide variety of feedstock used for the biochar production based on the cost effectiveness, ease availability and they are ecofriendly to the environment. Among the thermochemical processes, pyrolysis is the promising techniques followed for the production of BC. The stabilization efficacy was mainly determined by cation exchange capacity, pH, and ash content of the biochar. The physicochemical characteristic of the biochar is analyzed using various methods such as SEM, FTIR, TGA and BET analysis. The surface area plays a major role in the metal sorption. The quality characteristics of biochar as a soil amendment varied greatly with the feedstock materials and the pyrolysis conditions. Biochar plays a great role in increasing the pH which helps the acidic soil region and its high-water retention capacity enhance the moisture level in the soil which enhances the microbial communities and its activity. Biochar becomes stabilized in the soil by interacting with soil particles. The inherent characteristics of the biochar as dictated by feedstock and pyrolysis conditions, interact with climatic conditions such as precipitation and temperature to influence how long biochar carbon remains stored in the soil. Due to its carbon sequestration in the soil, it helps in increasing the fertility of the soil and also enhances the crop yield.

2015 ◽  
Vol 166 (6) ◽  
pp. 399-407 ◽  
Author(s):  
Barbara Moser ◽  
Marek Metslaid ◽  
Lorenz Walthert ◽  
Ulrich Wasem ◽  
Thomas Wohlgemuth

Regeneration potential of different Scots pine and Norway spruce provenances under variable drought Rising temperatures will lead to extended periods of summer drought, which may challenge the persistence of Scots pine and Norway spruce in dry alpine valleys where these species play an important role in the protection against natural hazards. We tested whether the natural regeneration of the two species in the Rhine valley near Chur, Switzerland, might be limited under future climatic conditions and we compared the performance of autochthonous provenances with that of seedlings originating from regions with already drier summer climate such as the Rhone valley, continental Eastern Europe or the Mediterranean basin. Seeds of Scots pine and Norway spruce were sown repeatedly in forest clearings at three south-exposed sites in the Rhine valley near Chur, Switzerland. Soil moisture was manipulated to a minor extent with throughfall reduction roofs. In both species, regeneration success was primarily driven by the weather conditions during the three months following seed sowing: the seedlings having emerged in the rainy spring of 2013 had a higher survival rate and accumulated up to five times more aboveground biomass than the seedlings emerging in the dry spring of 2011. In years with an average or even positive water balance, Scots pine seedlings were able to establish at all sites. In Norway spruce, by contrast, establishment rate exceeded 10% of viable seeds only at the site with the highest water retention capacity. In years with a positive water balance during spring, the seedlings from the Rhine and Rhone valleys outperformed those from most Mediterranean and Eastern European provenances, while no differences between provenances were found in the dry spring of 2011. We suggest that periodical regeneration of Scots pine will be likely in the Rhine valley even under future climatic conditions, whereas the establishment of Norway spruce may remain an exceptional event in dry, south-exposed clearings.


Author(s):  
Anthony S. R. Juo ◽  
Kathrin Franzluebbers

Allophanic soils are dark-colored young soils derived mainly from volcanic ash. These soils typically have a low bulk density (< 0.9 Mg/m3), a high water retention capacity (100% by weight at field capacity), and contain predominantly allophanes, imogolite, halloysite, and amorphous Al silicates in the clay fraction. These soils are found in small, restricted areas with volcanic activity. Worldwide, there are about 120 million ha of allophanic soils, which is about 1% of the Earth's ice-free land surface. In tropical regions, allophanic soils are among the most productive and intensively used agricultural soils. They occur in the Philippines, Indonesia, Papua New Guinea, the Caribbean and South Pacific islands, East Africa, Central America, and the Andean rim of South America. Allophanic soils are primarily Andisols and andic Inceptisols, Entisols, Mollisols, and Alfisols according to the Soil Taxonomy classification. Allophanic soils generally have a dark-colored surface soil, slippery or greasy consistency, a predominantly crumb and granular structure, and a low bulk density ranging from 0.3 to 0.8 Mg/m3. Although allophanic soils are apparently well-drained, they still have a very high water content many days after rain. When the soil is pressed between fingers, it gives a plastic, greasy, but non-sticky sensation of a silty or loamy texture. When dry, the soil loses its greasiness and becomes friable and powdery. The low bulk density of allophanic soils is closely related to the high soil porosity. For example, moderately weathered allophanic soils typically have a total porosity of 78%, with macro-, meso-, and micropores occupying 13%, 33%, and 32%, respectively. Water retained in the mesopores is readily available for plant uptake. Water retained in the micropores is held strongly by soil particles and is not readily available for plant use. The macropores provide soil aeration and facilitate water infiltration. The high water retention capacity is also associated with the high soil porosity. In allophanic soils formed under a humid climate, especially those containing large amounts of allophane, the moisture content at field capacity can be as high as 300%, calculated on a weight basis. Such extremely high values of water content seem misleading.


2019 ◽  
Vol 20 (3) ◽  
pp. 1793-1805
Author(s):  
Julia Gebert ◽  
Alexander Groengroeft

Abstract Purpose Climate change necessitates heightening and strengthening of dikes, requiring large volumes of suitable soil. This study investigated soil ripening and long-term development of hydraulic behaviour of a dike constructed from slightly contaminated, partially dewatered dredged material from the Port of Hamburg under realistic conditions of construction and operation. Materials and methods Two test fields of 126 m2 each were constructed in 2004 for long-term analysis of hydraulic behaviour in combination with the possible mobilisation of contaminants. In test field 1 (MS), the 1-m-thick cover above the sand core consisted of traditionally used alluvial marsh sediment (reference), while in test field 2, the lower 0.7 m of the cover was substituted with dredged material (DM + MS). An HDPE tray below each field served the collection of bottom fluxes and hence the quantification of discharges and analysis of their chemical composition. In 2012, an excavation was carried out to inspect the development of the soil structure. Results and discussion The discharge pattern revealed three distinct phases related to the post-construction structure development and therefore physical ripening of the soils. Within a single year, bottom fluxes typically started in mid-winter and ended in late spring. The dike cover containing DM had a high water retention capacity; however, the vertically continuous primary shrinkage cracks led to higher total bottom fluxes compared to the dike constructed from MS only. System hydraulic conductivities increased by up to six orders of magnitude compared to the as-built condition before soil ripening and structuring. The dredged material maintained a reduced geochemical status for about two years after construction. After first shrinkage and intrusion of oxygen, the material changed to an oxidised state, earmarking the onset of the chemical ripening process. Oxidising conditions were sustained in the long term, seen from the absence of previously elevated ammonium concentrations in the dike seepage. Conclusions System hydraulics of the test field with dredged material were mainly determined by the covering layer of marsh sediment. After construction, the dredged material underwent physical, chemical and biological soil ripening processes, coupled to a respective change in discharge patterns, which, however, did not impair dike stability. It is recommended that soil ripening processes are induced and completed as part of the material’s pre-treatment, precluding the formation of irreversible shrinkage cracks and changeover of redox conditions after construction. The findings contribute to assessing the feasibility of the beneficial use of dredged material.


2021 ◽  
Author(s):  
Eduardo Cejudo ◽  
Daniela Ortega-Camacho ◽  
Eduardo Arturo García-Vargas ◽  
Elizabeth Hernández-Alarcón

Abstract Karstic wetlands provide important ecosystem services such as maintenance of hydrological balance, flood regulation, drinking water supply and nutrients cycling. It is important to conserve and maintain karstic wetlands due to its interaction with groundwater systems and its socioeconomic relevance. The objective of this research was to generate base-line knowledge of the microtopography, hydroperiod and biogeochemical characteristics of poorly known tropical karstic marshes by testing two hypotheses, the phreatotrophic nature of tropical karstic marshes, and the alteration of its biogeochemistry by a highway dividing the marsh. The study site is located in the north of the state of Quintana Roo (Mexico), in pseudo-paludal depressions associated to fractures. The water level varied from few centimeters below the ground to more than 100 cm. We demonstrate that the wetland is groundwater-fed with differences among groundwater, interstitial and surface water in almost all parameters measured. The water is calcium bicarbonate type; the main processes occurring are recharge, evaporation and rock dissolution. Our results suggests active denitrification, low phosphates attributed to Ca- and Fe/Al-bound P, elevated alkalinity and sulfate reduction due to anaerobic conditions in water and soil. The soil reflect its sedimentary origin, the bulk density is low with very high water retention capacity. We do not have enough evidence of the highway modifying the biogeochemistry or hydrology of the marsh. These karstic wetlands provide important provisioning and supporting ecosystem services that should be studied, acknowledged and maintained.


2021 ◽  
Vol 25 (2) ◽  
pp. 90-98
Author(s):  
E.T. Tyurin ◽  
◽  
A.A. Zuikov ◽  
A.I. Bondarev ◽  
L.P. Gulyanz ◽  
...  

The influence of nanofibrillar cellulose samples on the coating compositions water retention is considered. It was shown that gels of nanofibrillar cellulose and coating compositions based on them are distinguished by a high water-retention capacity during centrifugation (50.8% and 31.0% versus 17.7% with NaCMC). A preliminary assessment of the printing and technical properties of light weight coated paper (LWC) using nanofibrillar cellulose in the coating composition has been carried out. The technical characteristics of nanofibrillar cellulose have been determined, formulations of lightweight paper coatings have been developed for high-speed modern equipment.


2019 ◽  
Vol 32 (1) ◽  
pp. 1-8
Author(s):  
N. Sharma ◽  
T. Sinderpal

Physico-chemical properties are crucial characteristics of hydrocolloids as they decide the applicability of them. Rheology of system, flow behaviour and mechanical properties make hydrocolloids suitable for food industry. Modification of consistency or texture properties of functional polymers also controls their sensory characteristics, thereby they become significant essences such as thickener, gelling agents, foaming agent, texture modifier, viscosifier, emulsifier, stabilizer and binder. Industrial and pharmaceutical applications are also controlled by some suitable physico-chemical properties of hydrocolloids. The polysaccharide gum exudates constitute a architecturally distinct class of complex biomacromolecules having unique physico-chemical properties. Due to their good bio/tissue compatibility, non-toxicity, they are extensively used in the field of tissue engineering, drug delivery and wound healing. Chemical and molecular architecture of hydrocolloids in turn controls their physico-chemical and functional properties. Sterculia gum is a substituted rhamnogalacturonoglycan (pectic) type exudate gum used as suspending agent, gelling agents, emulsifier, bulk laxative, dental adhesive, drug delivery agent and wound healing agent. It exhibits high water retention capacity, high viscosity and least solubility. Solutions of sterculia gum are viscoelastic and thixotropic. Sterculia gum has been recommended as effective wound dressing material as it can form a intensely adhesive gel when dispersed in minimum ammount of water. Owing to wide applications and distinctive properties of sterculia gum, present work is an endeavor to summarize the molecular organization, chemical configuration and physico-chemical properties of sterculia gum and the factors affecting physico-chemical properties of sterculia gum.


2021 ◽  
Author(s):  
Willem G van Herk ◽  
Robert S Vernon ◽  
Ted J Labun ◽  
Mika H Sevcik ◽  
Timothy D Schwinghamer

Abstract We present findings of a general survey of pest wireworms in Alberta, Saskatchewan, and Manitoba conducted from 2004 to 2019; the first such survey of the Canadian Prairie provinces since that published by Glen et al. (1943). Samples were collected from 571 farmland locations where crop damage from wireworms was observed or suspected, and a total of 5,704 specimens (3,548 larvae, 2,156 beetles) were identified. Most specimens (96.9%) were identified as Hypnoidus bicolor (3,278), Selatosomus aeripennis destructor (1,280), Limonius californicus (842), and Aeolus mellillus (125). This suggests that H. bicolor has replaced S. a. destructor as the predominant species and that the relative importance of L. californicus as a pest species has increased since earlier reports. Despite the relatively small number of specimens collected per location (approx. 10), H. bicolor and S. a. destructor, and S. a. destructor and L. californicus were frequently collected at or near the same location (within 1 km). We provide species records and incidence of co-occurrence at different spatial scales, discuss potential reasons for and implications of shifts in species composition, implications of species co-occurrence for managing wireworm pests in crop production, and outline pertinent research needs. A path analysis approach used to correlate incidence of the main species with various soil characteristics indicated that organic matter, cation exchange capacity, and water retention capacity all had a significant species-specific influence on wireworm presence.


Author(s):  
Thomas Cornelius Buch-Hanser ◽  
Guangli Du ◽  
David John Duffus

<p>Given the rapid increase in urban populations, combined with the effects of climate change, cities are struggling to provide green spaces to address liveability as well as adaptability to new challenges. Water retention and bio-diversity are the main advantages of green roofs. There are, however, limitations to green roofs that impede their acceptance and proliferation. There is for example uncertainty on how much water they retain during major storm events. In terms of building technology, green roofs today aren’t robust, and the risk for leakage through the roof membrane is disproportionally high when compared to the cost. A newly developed innovative green roof system with high water retention capacity and high durability will be presented. The patented prefabricated technology incorporate insulation and membrane into a single concrete element, ensuring improved robustness, quickened building times and a long term durable product. Initial indications for pricing indicate that the system is price-neutral when compared with green roofs as they are built today. The optimized structural performance obtain same loadbearing capacity, as existing systems, in spite of the relatively increased space created for water reservoir, without compromising the insulation capacity, hence the new green roof system further contribute to increased sustainability.</p>


2014 ◽  
Vol 6 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Rakesh Kumar ◽  
Pramila Aggarwal ◽  
Ravendra Singh ◽  
Debashis Chakraborty ◽  
Ranjan Bhattacharya ◽  
...  

In order to assess soil health of Kharkhoda and Gohana blocks of Sonipat district (a part of western Yamuna canal irrigated region), important parameters namely pH, electrical conductivity (EC), texture, bulk density (BD), saturated hydraulic conductivity (HC), soil organic carbon (OC), available water retension capacity (AWRC) and non capillary pores (NCP) were measured by collecting undisturbed soil samples in nearly 66 villages. Soil physical rating index (PI) method was used to compute PI which was an indicator of soil physical health of thatregion. Results revealed that in Gohana and Kharkhoda blocks, nearly 90% area had pH <8.0 and EC>4 dS m-1, which indicated that soils were saline. Prediction maps of soil BD showed that 75% of the total area in 15-30 cm soil layer had BD above >1.6 mg m-3, which indicated the presence of hard pan in subsurface. HC data of subsurface layer also showed that 60% of the area had values<0.5 cm hr-1 which reconfirmed the presence of hard pan. For both surface as well as subsurface soil layers, mostly AWC was >10% which indicated adequate water retention capacity of these soils. However 85% of subsurface had poor soil aeration capacity as indicated NCP range < 10 %. Prediction map of PI for subsurface layer showed that majority of area had PI<0.4 which indicated that expected yield of the crop cannot be more than 70% of the potential yield even under normal or higher levels of fertilizer and water inputs.


2021 ◽  
Vol 11 (19) ◽  
pp. 8914
Author(s):  
Ghizlane Enaime ◽  
Manfred Lübken

Agricultural activities face several challenges due to the intensive increase in population growth and environmental issues. It has been established that biochar can be assigned a useful role in agriculture. Its agronomic application has therefore received increasing attention recently. The literature shows different applications, e.g., biochar serves as a soil ameliorant to optimize soil structure and composition, and it increases the availability of nutrients and the water retention capacity in the soil. If the biochar is buried in the soil, it decomposes very slowly and thus serves as a long-term store of carbon. Limiting the availability of pesticides and heavy metals increases soil health. Biochar addition also affects soil microbiology and enzyme activity and contributes to the improvement of plant growth and crop production. Biochar can be used as a compost additive and animal feed and simultaneously provides a contribution to minimizing greenhouse gas emissions. Several parameters, including biochar origin, pyrolysis temperature, soil type when biochar is used as soil amendment, and application rate, control biochar’s efficiency in different agricultural applications. Thus, special care should be given when using a specific biochar for a specific application to prevent any negative effects on the agricultural environment.


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