scholarly journals Geo-Agriculture: Reviewing Opportunities through Which the Geosphere Can Help Address Emerging Crop Production Challenges

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 971 ◽  
Author(s):  
Chris Pratt ◽  
Kate Kingston ◽  
Bronwyn Laycock ◽  
Ian Levett ◽  
Steven Pratt
Keyword(s):  
Crop Production ◽  
Agricultural Sector ◽  
High Surface ◽  
High Surface Area ◽  
Soil Surface ◽  
Suspended Sediments ◽  
Agricultural Landscapes ◽  
Mineral Nutrient ◽  
Agricultural Systems ◽  
Geological Materials

The agricultural sector faces looming challenges including dwindling fertiliser reserves, environmental impacts of conventional soil inputs, and increasingly difficult growing conditions wrought by climate change. Naturally-occurring rocks and minerals may help address these challenges. In this case, we explore opportunities through which the geosphere could support viable agricultural systems, primarily via a literature review supplemented by data analysis and preliminary-scale experimentation. Our objective is to focus on opportunities specifically relating to emerging agricultural challenges. Our findings reveal that a spectrum of common geological materials can assist across four key agricultural challenges: 1. Providing environmentally-sustainable fertiliser deposits especially for the two key elements in food production, nitrogen (via use of slow release N-rich clays), and phosphorus (via recovery of the biomineral struvite) as well as through development of formulations to tap into mineral nutrient reserves underlying croplands. 2. Reducing contamination from farms—using clays, zeolites, and hydroxides to intercept, and potentially recycle nutrients discharged from paddocks. 3. Embedding drought resilience into agricultural landscapes by increasing soil moisture retention (using high surface area minerals including zeolite and smectite), boosting plant availability of drought protective elements (using basalts, smectites, and zeolites), and decreasing soil surface temperature (using reflective smectites, zeolites, and pumices), and 4. mitigating emissions of all three major greenhouse gases—carbon dioxide (using fast-weathering basalts), methane (using iron oxides), and nitrous oxide (using nitrogen-sorbing clays). Drawbacks of increased geological inputs into agricultural systems include an increased mining footprint, potential increased loads of suspended sediments in high-rainfall catchments, changes to geo-ecological balances, and possible harmful health effects to practitioners extracting and land-applying the geological materials. Our review highlights potential for ‘geo-agriculture’ approaches to not only help meet several key emerging challenges that threaten sustainable food and fiber production, but also to contribute to achieving some of the United Nations Sustainable Development Goals—‘Zero Hunger,’ ‘Life on Land,’ and ‘Climate Action.’

scholarly journals Nanopesticides: Current status and scope for their application in agriculture

2021 ◽  
Author(s):  
Jayant Yadav ◽  
Poonam Jasrotia ◽  
Ajay Kumar Bhardwaj ◽  
Prem Lal Kashyap ◽  
Sudheer Kumar ◽  
...  
Keyword(s):  
Crop Production ◽  
Food Systems ◽  
Insect Pests ◽  
High Surface ◽  
High Surface Area ◽  
Plant Diseases ◽  
Current Status ◽  
Human Beings ◽  
Biotic Stresses ◽  
Volume Property

 Nanotechnology is a rapidly evolving field that has the potential to revolutionise food systems and counter the present-day challenge of food security. It envisages taking agriculture from the era of indiscriminate natural resource use and environmental degradation to the brave new world of advanced systems with enhanced material use efficiency and targeted applications to reduce crop losses caused due to abiotic-biotic stresses as well as to give due considerations to the environment. To manage plant diseases and insect pests, pesticides are inevitably used in agriculture. However, the higher dosage of these chemicals on a per hectare basis has resulted in many environmental and health hazards. To tackle the conventional pesticide related issues, a new field of science called nanotechnology has led to the development of nanopesticides that have less active ingredients, but better efficiency. The nanopesticides contain the carrier molecule or the active nanosized ingredient with a very high surface area to the volume property that provides them unique exploitable-advantages. Several formulations, viz., nanoemulsions, nanosuspensions, nanogels, metal compound-based nanopesticides, have been developed for different modes of action and vivid applications. The biggest advantage comes due to the small size of the particles that help in properly spreading the ingredients on the pest surface and, thus, producing a better action than conventional pesticides. The use of nanoparticles in the form of nanopesticides, nanofertilisers, and nano delivery systems is on the increase day by day due to their higher efficiency and reduced dosage requirements. However, human beings and other organisms are also getting exposed to the nano-entities during the application or afterwards. The interactions of these engineered nano-entities with biological systems are relatively unknown thus far. Therefore, before their wider usage in crop production and protection, a better understanding of their interactions, and adverse effects, if any, is also crucial for a sustainable transition.  

Applications and perspectives of using nanomaterials for sustainable plant nutrition

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Allah Ditta ◽  
Muhammad Arshad
Keyword(s):  
Plant Nutrition ◽  
Crop Production ◽  
High Surface ◽  
High Surface Area ◽  
Particle Morphology ◽  
High Reactivity ◽  
Growth And Yield ◽  
Future Research ◽  
Sustainable Crop Production ◽  
Future Demands

AbstractNanotechnology opens a large scope of novel applications in the fields of plant nutrition needed to meet the future demands of the growing population because nanoparticles (NPs) have unique physicochemical properties, i.e. high surface area, high reactivity, tunable pore size, and particle morphology. Management of optimum nutrients for sustainable crop production is a priority-based area of research in agriculture. In this regard, nanonutrition has proved to be the most interesting area of research and concerns with the provision of nano-sized nutrients for sustainable crop production. Using this technology, we can increase the efficiency of micro- as well as macronutrients of plants. In the literature, various NPs and nanomaterials (NMs) have been successfully used for better nutrition of crop plants compared to the conventional fertilizers. This review summarizes these NPs and NMs into macro-, micro-, and nanocarrier-based fertilizers and plant-growth-enhancing NPs with unclear mechanisms, describing their role in improving growth and yield of crops, concentration/rate of application, particle size, mechanism of action if known, toxic effects if any, and research gaps in the present research. Moreover, future research directions for achieving sustainable agriculture are also discussed in the appropriate section and at the end in the concluding remarks section.

Hydrothermal Carbonization of Biomass for Energy and Crop Production

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
M. Toufiq Reza ◽  
Janet Andert ◽  
Benjamin Wirth ◽  
Daniela Busch ◽  
Judith Pielert ◽  
...  
Keyword(s):  
Crop Production ◽  
Power Plants ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Hydrothermal Carbonization ◽  
Toxic Substances ◽  
Carbon Nanospheres ◽  
Thermochemical Pretreatment ◽  
Hot Compressed Water

AbstractHydrothermal carbonization (HTC) is a thermochemical pretreatment process where biomass is treated under hot compressed water to produce hydrochar. Hydrochar is a stable, hydrophobic, friable solid product, which has a fuel value similar to that of lignite coal. Among its other advantages, its capability to handle wet feed makes the HTC process most attractive. The complex reaction chemistry of HTC offers a huge potential for producing a variety of products, from fuel to supercapacitors, from carbon nanospheres to low cost adsorbents, from fertilizers to soil amenders. Hydrochar opens possibilities for replacing coal in existing coal-power plants. Its high surface area and adsorption characteristics make it compatible for use in supercapacitors. Hydrochar also contains high amounts of stable carbon and other nutrients, which are essential for soil amendment. Moreover, the HTC process liquid, especially if a short retention time is used, contains potentially toxic substances like phenols, furfurals, and their derivatives, which open opportunities for anaerobic digestion to produce biogas. This review paper gives an overview of the HTC process parameters, reactions, and the use of hydrochar for energy and crop production

scholarly journals Drivers of abrupt and gradual changes in agricultural systems in Chad

2020 ◽  
Vol 20 (3) ◽  
Author(s):  
Erik Nilsson ◽  
Per Becker ◽  
Cintia Bertacchi Uvo
Keyword(s):  
Food Security ◽  
Crop Production ◽  
Agricultural Sector ◽  
Rural Livelihoods ◽  
International Aid ◽  
Economic Transformation ◽  
Agricultural Systems ◽  
Market Prices ◽  
Economic Transformations

Abstract The countries in the Sahel are undergoing rapid changes due to a mixture of demographic, ecological, and economic transformations. Rural livelihoods in these countries are predominantly engaged in agriculture, which is a foundational component of both food security and the general economy. The relationships between ongoing socio-economic transformation and the agricultural sector are clearly important to address poverty and sustainable development, but have received little academic attention on a subnational level of analysis. This paper addresses this by bringing together new datasets on demography, international aid, food security reports, and soil moisture to analyze the drivers of change in the agricultural sector on a subnational level in Chad. Both regression analyses and qualitative methods based on descriptions in food security reports are used to evaluate the relationships between these datasets to agricultural statistics for the period 1990–2016. It finds that changes to crop water availability from rainfall largely are decoupled from the long-term increases in crop production. On the other hand, it shows that population changes and international aid can explain differences in long-term agricultural changes between Chad’s regions. Moreover, stochastic factors such as farm support programs, market prices, access to new markets, and accommodation of refugees are identified as important to grasp abrupt changes in the crop production. Beyond the specific findings for Chad, this study presents a framework for improved evaluation of the drivers behind subnational crop production on multi-annual and decadal time scales, with broad applicability to agricultural systems in the Sahel.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Electron holography of catalysts

1995 ◽  
Vol 53 ◽  
pp. 416-417
Author(s):  
A. K. Datye ◽  
D. S. Kalakkad ◽  
L. F. Allard ◽  
E. Völkl
Keyword(s):  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Scale ◽  
Nano Particles ◽  
Phase Image ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Phase Information ◽  
Particle Structure

The active phase in heterogeneous catalysts consists of nanometer-sized metal or oxide particles dispersed within the tortuous pore structure of a high surface area matrix. Such catalysts are extensively used for controlling emissions from automobile exhausts or in industrial processes such as the refining of crude oil to produce gasoline. The morphology of these nano-particles is of great interest to catalytic chemists since it affects the activity and selectivity for a class of reactions known as structure-sensitive reactions. In this paper, we describe some of the challenges in the study of heterogeneous catalysts, and provide examples of how electron holography can help in extracting details of particle structure and morphology on an atomic scale.Conventional high-resolution TEM imaging methods permit the image intensity to be recorded, but the phase information in the complex image wave is lost. However, it is the phase information which is sensitive at the atomic scale to changes in specimen thickness and composition, and thus analysis of the phase image can yield important information on morphological details at the nanometer level.

Structure and composition of metal particles in Pt-Sn/Al2O3 bimetallic catalysts

1990 ◽  
Vol 48 (4) ◽  
pp. 278-279
Author(s):  
A. Sachdev ◽  
J. Schwank
Keyword(s):  
Bimetallic Catalysts ◽  
Bimetallic Catalyst ◽  
Size Structure ◽  
High Surface ◽  
High Surface Area ◽  
Metal Particles ◽  
Alloy Formation ◽  
Particle Size Range ◽  
Oxide Supports ◽  
Petroleum Fractions

Platinum - tin bimetallic catalysts have been primarily utilized in the chemical industry in the catalytic reforming of petroleum fractions. In this process the naphtha feedstock is converted to hydrocarbons with higher octane numbers and high anti-knock qualities. Most of these catalysts contain small metal particles or crystallites supported on high surface area insulating oxide supports. The determination of the structure and composition of these particles is crucial to the understanding of the catalytic behavior. In a bimetallic catalyst it is important to know how the two metals are distributed within the particle size range and in what way the addition of a second metal affects the size, structure and composition of the metal particles. An added complication in the Pt-Sn system is the possibility of alloy formation between the two elements for all atomic ratios.

Intercalation of First Row Transition Metals inside Covalent-Organic Frameworks (COF): a Strategy to Fine Tune the Electronic Properties of Porous Crystalline Materials

2018 ◽  
Author(s):  
Srimanta Pakhira ◽  
Jose Mendoza-Cortes
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Electronic Properties ◽  
High Surface ◽  
Electronic Devices ◽  
High Surface Area ◽  
Main Role ◽  
Covalent Organic Frameworks ◽  
Porous Network ◽  
Crystalline Materials

<div>Covalent organic frameworks (COFs) have emerged as an important class of nano-porous crystalline materials with many potential applications. They are intriguing platforms for the design of porous skeletons with special functionality at the molecular level. However, despite their extraordinary properties, it is difficult to control their electronic properties, thus hindering the potential implementation in electronic devices. A new form of nanoporous material, COFs intercalated with first row transition metal is proposed to address this fundamental drawback - the lack of electronic tunability. Using first-principles calculations, we have designed 31 new COF materials <i>in-silico</i> by intercalating all of the first row transition metals (TMs) with boroxine-linked and triazine-linked COFs: COF-TM-x (where TM=Sc-Zn and x=3-5). This is a significant addition considering that only 187 experimentally COFs structures has been reported and characterized so far. We have investigated their structure and electronic properties. Specifically, we predict that COF's band gap and density of states (DOSs) can be controlled by intercalating first row transition metal atoms (TM: Sc - Zn) and fine tuned by the concentration of TMs. We also found that the $d$-subshell electron density of the TMs plays the main role in determining the electronic properties of the COFs. Thus intercalated-COFs provide a new strategy to control the electronic properties of materials within a porous network. This work opens up new avenues for the design of TM-intercalated materials with promising future applications in nanoporous electronic devices, where a high surface area coupled with fine-tuned electronic properties are desired.</div>

Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Layer ◽  
Active Surface ◽  
Active Surface Area ◽  
High Concentration ◽  
Copper Electrodes ◽  
Surface Enhanced ◽  
Local Current

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>

Activated carbon from molasses efficiency for Cr(VI), Pb(II) and Cu(II) adsorption: A mechanistic study

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Sugar Industry ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
Mechanistic Study ◽  
Acid Mixture ◽  
Maximum Adsorption Capacity ◽  
Good Potential

Activated carbon was prepared from molasses, which are natural precursors of vegetable origin resulting from the sugar industry. A simple elaboration process, based on chemical activation with phosphoric acid, was proposed. The final product, prepared by activation of molasses/phosphoric acid mixture in air at 500°C, presented high surface area (more than 1400 m2/g) and important maximum adsorption capacity for methylene blue (625 mg/g) and iodine (1660 mg/g). The activated carbon (MP2(500)) showed a good potential for the adsorption of Cr(VI), Cu(II) and Pb(II) from aqueous solutions. The affinity for the three ions was observed in the following order Cu2+ Cr6+ Pb2+. The process is governed by monolayer adsorption following the Langmuir model, with a correlation coefficient close to unity.

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