scholarly journals Simulating carbon capture by enhanced weathering with croplands: an overview of key processes highlighting areas of future model development

2017 ◽  
Vol 13 (4) ◽  
pp. 20160868 ◽  
Author(s):  
Lyla L. Taylor ◽  
David J. Beerling ◽  
Shaun Quegan ◽  
Steven A. Banwart

Enhanced weathering (EW) aims to amplify a natural sink for CO 2 by incorporating powdered silicate rock with high reactive surface area into agricultural soils. The goal is to achieve rapid dissolution of minerals and release of alkalinity with accompanying dissolution of CO 2 into soils and drainage waters. EW could counteract phosphorus limitation and greenhouse gas (GHG) emissions in tropical soils, and soil acidification, a common agricultural problem studied with numerical process models over several decades. Here, we review the processes leading to soil acidification in croplands and how the soil weathering CO 2 sink is represented in models. Mathematical models capturing the dominant processes and human interventions governing cropland soil chemistry and GHG emissions neglect weathering, while most weathering models neglect agricultural processes. We discuss current approaches to modelling EW and highlight several classes of model having the potential to simulate EW in croplands. Finally, we argue for further integration of process knowledge in mathematical models to capture feedbacks affecting both longer-term CO 2 consumption and crop growth and yields.

Soil Research ◽  
2004 ◽  
Vol 42 (8) ◽  
pp. 865 ◽  
Author(s):  
M. E. Alves ◽  
A. Lavorenti

Soil pH measured in 1 m NaF (pHNaF) can be a useful tool for soil classification and to provide better advice on the chemical management of agricultural soils in the tropics. In this study, we verified the effects of clay mineralogy on pHNaF values of non-allophanic soils of São Paulo State, Brazil. Fourteen subsurface soil samples were characterised for chemical properties, clay content, clay mineralogy, and for pHNaF values, which were measured in the whole soil and in both natural and deferrified (dithionite-treated) clay fractions. Regression and correlation analyses showed that both ammonium-oxalate-extractable Al (Alo) and gibbsite contents have positive relationships with both clay and soil pHNaF values. On the other hand, kaolinite is inversely related to the pHNaF measured in the clay and has nonsignificant effect on soil pHNaF. X-ray diffraction patterns of dithionite-treated clays did not show disruption of kaolinite or gibbsite after the treatment with 1 m NaF, suggesting that the displacement of surface OH groups by F– seems to be the main mechanism associated with the pH increase verified in the NaF solution after its contact with the deferrified clay fraction. The smaller influence of hematite on pHNaF seems to be due to its correlation to Alo. Goethite and ammonium-oxalate-extractable Fe (Feo) exert no effect on pHNaF. Finally, the relationships observed in the present study strongly suggest that pHNaF values <10.3 measured in non-allophanic kaolinitic soils with low levels of non-humified organic matter are essentially due to their smaller Alo and gibbsite contents, which agrees with the direct correlation verified between pHNaF and soil weathering degree.


2012 ◽  
Vol 9 (1) ◽  
pp. 151-189 ◽  
Author(s):  
R. Felber ◽  
R. Hüppi ◽  
J. Leifeld ◽  
A. Neftel

Abstract. Biochar, a pyrolysis product of organic residues, is an amendment for agricultural soils to improve soil fertility, sequester CO2 and reduce greenhouse gas (GHG) emissions. In highly weathered tropical soils laboratory incubations of soil-biochar mixtures revealed substantial reductions for nitrous oxide (N2O) and carbon dioxide (CO2). In contrast, evidence is scarce for temperate soils. In a three-factorial laboratory incubation experiment two different temperate agricultural soils were amended with green waste and coffee grounds biochar. N2O and CO2 emissions were measured at the beginning and end of a three month incubation. The experiments were conducted under three different conditions (no additional nutrients, glucose addition, and nitrate and glucose addition) representing different field conditions. We found mean N2O emission reductions of 60 % compared to soils without addition of biochar. The reduction depended on biochar type and soil type as well as on the age of the samples. CO2 emissions were slightly reduced, too. NO3– but not NH4+ concentrations were significantly reduced shortly after biochar incorporation. Despite the highly significant suppression of N2O emissions biochar effects should not be transferred one-to-one to field conditions but need to be tested accordingly.


2013 ◽  
Vol 27 (3) ◽  
pp. 239-246 ◽  
Author(s):  
A.E. Ajayi ◽  
M.S. Dias Junior ◽  
N. Curi ◽  
I. Oladipo

Abstract This study aimed to investigate the mineralogy, moisture retention, and the compressive response of two agricultural soils from South West Nigeria. Undisturbed soil cores at the A and B horizons were collected and used in chemical and hydrophysical characterization and confined compression test. X-ray diffractograms of oriented fine clay fractions were also obtained. Our results indicate the prevalence of kaolinite minerals relating to the weathering process in these tropical soils. Moisture retention by the core samples was typically low with pre-compression stress values ranging from50 to 300 kPa at both sites. Analyses of the shape of the compression curves highlight the influence of soil moisture in shifts from the bi-linear to S-shaped models. Statistical homogeneity test of the load bearing capacity parameters showed that the soil mineralogy influences the response to loading by these soils. These observations provide a physical basis for the previous classification series of the soils in the studied area. We showed that the internal strength attributes of the soil could be inferred from the mineralogical properties and stress history. This could assist in decisions on sustainable mechanization in a datapoor environment.


Author(s):  
Paul Witherell ◽  
Shaw Feng ◽  
Timothy W. Simpson ◽  
David B. Saint John ◽  
Pan Michaleris ◽  
...  

In this paper, we advocate for a more harmonized approach to model development for additive manufacturing (AM) processes, through classification and metamodeling that will support AM process model composability, reusability, and integration. We review several types of AM process models and use the direct metal powder bed fusion AM process to provide illustrative examples of the proposed classification and metamodel approach. We describe how a coordinated approach can be used to extend modeling capabilities by promoting model composability. As part of future work, a framework is envisioned to realize a more coherent strategy for model development and deployment.


2021 ◽  
Author(s):  
Saara Lind ◽  
Marja Maljanen ◽  
Merja Myllys ◽  
Mari Räty ◽  
Sanna Kykkänen ◽  
...  

&lt;p&gt;Agricultural soils are a significant source of greenhouse gas (GHG) emissions. To study these emissions, we are currently building three research platforms that consist of full eddy covariance instrumentation for determination of net ecosystem carbon dioxide exchange and fluxes of methane and nitrous oxide. These platforms will be completed with supporting weather, plant and soil data collection. Two of our platforms are sites on organic soils with a thick peat layer (&gt;60 cm) and the third one is on a mineral soil (silt loam). To study the role of the grassland management practises at these sites, we have initiated ORMINURMI-project. Here, we will characterise the effects of ground water table (high vs. low), crop renewal methods (autumn vs. summer) and plant species (tall fescue vs. red glover grass) on greenhouse gas budgets of grass production. Also effect on yield amount and nutrient quality will be determined. In this presentation, we will present the preliminary data collected at these research platforms and our plans for the use of these data in the coming years.&lt;/p&gt;


2009 ◽  
pp. 95-110 ◽  
Author(s):  
Ratko Kadovic ◽  
Snezana Belanovic ◽  
Milan Knezevic ◽  
Jelena Belojica ◽  
Jasmina Knezevic

In the last two decades, S and N critical loads have been used as indicators of ecosystem sustainability to soil acidification. The effect of acidification on the soil in forest ecosystems and their further development was the subject of numerous studies, based on which several mathematical models were developed. This paper presents the results of the analysis of acidification processes in brown podzolic soil on granodiorites in the stands of spruce and spruce and fir in the area of NP 'Kopaonik'. Critical loads of sulphur and nitrogen in these soils are presented using VSD model.


India is a worldwide agriculture business powerhouse. Future of agriculture-based products depends on the crop production. A mathematical model might be characterized as a lot of equations that speak to the conduct of a framework. By using mathematical model in agriculture field, we can predict the production of crop in particular area. There are various factors affecting crops such as Rainfall, GHG Emissions, Temperature, Urbanization, climate, humidity etc. A mathematical model is a simplified representation of a real-world system. It forms the system using mathematical principles in the form of a condition or a set of conditions. Suppose we need to increase the crop production, at that time the mathematical model plays a major role and our work can be easier, more significant by using the mathematical model. Through the mathematical model we predict the crop production in upcoming years. .AI, ML, IOT play a major role to predict the future of agriculture, but without mathematical models it is not possible to predict crop production accurately. To solve the real-world agriculture problem, mathematical models play a major role for accurate results. Correlation Analysis, Multiple Regression analysis and fuzzy logic simulation standards have been utilized for building a grain production benefit depending model from crop production. Prediction of crop is beneficiary to the farmer to analyze the crop management. By using the present agriculture data set which is available on the government website, we can build a mathematical model.


2018 ◽  
Vol 58 (3) ◽  
pp. 489 ◽  
Author(s):  
K. Taylor ◽  
J. A. D. Ranga Niroshan Appuhamy ◽  
J. Dijkstra ◽  
E. Kebreab

The aim of this study was to develop and evaluate mathematical models that predict mineral excretion, particularly calcium (Ca), magnesium (Mg) and selenium (Se), from lactating dairy cows. Mineral excretion can be affected by several dietary factors. A deficiency in Ca or Mg application to pasture, among other factors, can contribute to grass tetany or wheat pasture poisoning in cows, whereas an excess can cause runoff into water supplies. Manure application with high Se concentration can also result in runoff, causing the bioaccumulation of selenium in aquatic ecosystems, wetland habitats and estuaries, leading to toxic levels in fish. A database composed of studies relating to mineral utilisation in lactating dairy cows conducted after and including the year 2000 was compiled. A meta-analysis was conducted with the aim of creating multiple empirical equations to predict Ca, Mg and Se excretion from lactating dairy cows. Calcium intake, feed Ca content, milk yield, milk protein content and acid detergent fibre content in diet were positively and linearly related to Ca excretion. Dietary crude protein content and milk fat content were negatively related to Ca excretion. Magnesium intake, feed Mg content and milk yield were positively and linearly related to Mg excretion. Selenium content of diet and dry matter intake were linearly and positively related to Se excretion. Two sets of models were developed using or excluding the intake variable and both sets of models were evaluated with independent data originating from commercial herd or individual animals. In general, intake measurements improved prediction when evaluated with independent datasets (root mean square prediction error = 8% to 19% vs 14% to 26% of the average observed value). There were substantial mean biases, particularly those evaluated with data from a commercial farm, perhaps due to inaccurate feed intake measurements. Although there was generally good agreement between predicted and observed mineral excretion, model development and evaluation would benefit from an expanded database.


Author(s):  
Theresa M. Marteau

Meeting climate change targets to limit global warming to 2°C requires rapid and large reductions in demand for products that most contribute to greenhouse gas (GHG) emissions. These include production of bulk materials (e.g. steel and cement), energy supply (e.g. fossil fuels) and animal source foods (particularly ruminants and their products). Effective strategies to meet these targets require transformative changes in supply as well as demand, involving changes in economic, political and legal systems at local, national and international levels, building on evidence from many disciplines. This paper outlines contributions from behavioural science in reducing demand. Grounded in dual-process models of human behaviour (involving non-conscious and conscious processes) this paper considers first why interventions aimed at changing population values towards the environment are usually insufficient or unnecessary for reducing demand although they may be important in increasing public acceptability of policies that could reduce demand. It then outlines two sets of evidence from behavioural science towards effective systems-based strategies, to identify interventions likely to be effective at: (i) reducing demand for products that contribute most to GHG emissions, mainly targeting non-conscious processes and (ii) increasing public acceptability for policy changes to enable these interventions, targeting conscious processes. This article is part of the themed issue ‘Material demand reduction’.


Soil Research ◽  
2009 ◽  
Vol 47 (8) ◽  
pp. 747 ◽  
Author(s):  
K. L. Page ◽  
D. E. Allen ◽  
R. C. Dalal ◽  
W. Slattery

Increases in soil acidification have led to large increases in the application of aglime to Australian agricultural soils. The addition of aglime has the potential to increase greenhouse gas (GHG) emissions due to the release of CO2 during the chemical dissolution of aglime and due to pH-induced changes to soil biological processes. Currently, Australia’s GHG accounting system assumes that all the carbon contained in aglime is released to the atmosphere during dissolution in accordance with the Tier 1 methodology of the IPCC. However, a recent approach by TO West and AC McBride has questioned this assumption, hypothesising that a proportion of the carbon from riverine-transported aglime may be sequestered in seawater. In addition, there is presently no capacity within Australia’s carbon accounting system to quantify changes to GHG emissions from lime-induced changes to soil biological processes. Therefore, the primary objective of this review was to examine the chemical and biological processes occurring during the application of aglime and the subsequent fluxes in CO2, N2O, and CH4 from soil, with particular reference to the Australian environment. Estimates for CO2 emissions from aglime application in Australia using the contrasting methodologies of the IPCC and West and McBride were compared. Using the methodology of the IPCC it was determined that from the aglime applied in Australia in 2002, 0.995 Tg of CO2 would have been emitted, whereas this figure was reduced to 0.659–0.860 Tg of CO2 using the methodology of West and McBride. However, the accuracy of these estimates is currently limited by poor understanding of the manner in which aglime moves within the Australian landscapes. In addition, there are only a very small number of Australian studies that have examined the effect of aglime on GHG emissions due to changes in soil biological processes, limiting the ability of Australian modellers to accurately incorporate these processes within the carbon accounting system.


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