Areas Of Soil Science Research Articles

Desenvolvimento de helicônia em função de diferentes tipos de solo e doses de nitrogênio

Abstract Heliconia psittacorum is a plant that stands out in tropical floriculture due to its inflorescence with bracts of different colors and its high ornamental value. The aim of this study was to assess the influence of nitrogen applied under different management methods on the development of heliconia plants (H. psittacorum). The experiment was carried out in a greenhouse, in the soil science area, from May to December 2018, at the Belém Campus of the Federal Rural University of Amazonia (UFRA). A completely randomized design was used, in a 4 x 2 factorial scheme, distributed over 5 replications. The factors were 4 doses of nitrogen fertilization (0, 20, 40 and 60 kg ha-1 of N) and 2 types of soil (conventional cultivation and forest). The variables used to analyze the treatments were: height, pseudostem diameter, fresh weight of the pseudostem, flower stem, leaves, rhizome and root. The results of the experiment were subjected to analysis of variance, compared using the Tukey test, where appropriate, and regression studies by adjusting the equations according to the doses of N used. There were significant differences in all the variables studied. The results of this study show that there is probably a certain shortage of the elements needed for plant nutrition and, with a greater supply of N, there is greater root development to make up for this deficiency.

Interaction of geotechnics with society through education

The Federal University of Goiás (UFG) and the University of Brasília (UnB), in partnership with the company Eletrobras Furnas, have developed research and, based on this, extension projects aimed at education in a broad sense, in which they seek to disseminate and popularise technical-scientific knowledge. This paper aims to present and evaluate educational actions carried out in the area of soil science and geotechnics applied to engineering, geography, and the environment. To do so, the educational experiences developed within the scope of two extension projects are shared. Beside that, the relevance of publishing books and primer, with language adapted to lay society, within the scope of research projects, is analyzed. The results collected regarding the effectiveness of the extension actions as a tool for learning point to a positive evaluation by the students. Furthermore, social networks are an important tool for scientific dissemination and have the potential to disseminate knowledge more widely than in a classroom course. By comparing the number of citations in Google Scholar of the books and booklets with the papers arising from these projects, one can observe the reach of this type of publication, although its purpose is the popularisation of science, with reach in places not considered in the technical-scientific publication metrics. Finally, for effective scientific development, it is necessary to have public policies, effective interaction between universities, research centres and schools, and the participation of professional associations, funding and evaluation agencies, Education Departments and the Ministry of Education, Science, Technology and Innovation.

Konstantin Dmitrievich Glinka (23.06.1867 – 02.11.1927) – the first academician-soil scientist, organizer and first Director of V.V. Dokuchaev Soil Science Institute and the first Rector of Voronezh Agricultural Institute named after Emperor Peter I, Professor, full member of the USSR Academy of Sciences

Konstantin Dmitrievich Glinka made a major contribution to the development of such areas of soil science as genesis, geography, cartography and mineralogy of soils. He made the first world soil maps (1908, 1915, 1927), the first soil map of the Asian part of Russia (1927, jointly with L.I. Prasolov), classic studies of weathering processes and transformation of primary minerals into secondary, first studies of buried and relic soils, which laid the foundation for paleosoil science. Fundamental, encyclopedic textbook, written by K.D. Glinka “Soil science” went through six editions (1908–1936) and became a basic guide for many generations of soil scientists. The ideas of K.D. Glinka in the genesis of different types of soils, including gray forest soils, podzols, red earths, burozems (brown soils) have not lost their scientific value until the present day. His outstanding scientific, organizational and pedagogical contribution to the development of genetic soil science has earned K.D. Glinka a well-deserved fame as a scientist of world class.

Preferential Adsorption of Prominent Amino Acids in the Urease Enzyme of Sporosarcina pasteurii on Arid Soil Components: A Periodic DFT Study.

The urease enzyme is commonly used in microbially induced carbonate precipitation (MICP) and enzyme-induced carbonate precipitation (EICP) to heal and strengthen soil. Improving our understanding of the adsorption of the urease enzyme with various soil surfaces can lead to advancements in the MICP and EICP engineering methods as well as other areas of soil science. In this work, we use density functional theory (DFT) to investigate the urease enzyme's binding ability with four common arid soil components: quartz, corundum, albite, and hematite. As the urease enzyme cannot directly be simulated with DFT due to its size, the amino acids comprising at least 5% of the urease enzyme were simulated instead. An adsorption model incorporating the Gibbs free energy was used to determine the existence of amino acid-mineral binding modes. It was found that the nine simulated amino acids bind preferentially to the different soil components. Alanine favors corundum, glycine and threonine favor hematite, and aspartic acid favors albite. It was found that, under the standard environmental conditions considered here, amino acid binding to quartz is unfavorable. In the polymeric form where the side chains would dominate the binding interactions, hematite favors aspartic acid through its R-OH group and corundum favors glutamic acid through its R-Ket group. Overall, our model predicts that the urease enzyme produced by Sporosarcina pasteurii can bind to various oxides found in arid soil through its alanine, glycine, aspartic/glutamic acid, or threonine residues.

Response of crop residue incorporation on Partial factor productivity, recoveries and efficiencies of applied nutrients under maize-wheat cropping system

An experiment was conducted in farm area of Soil Science and Agricultural Chemistry, Birsa Agricultural University, Ranchi, to study the indigenous nutrient supply from nutrient omission plots with and without incorporation of crop residues and their response on partial factor productivity, recoveries and efficiencies of applied nutrients under maize-wheat cropping system. The experiment comprising five treatments with and without crop residues incorporation, replicated four times in a RBD. The results revealed that Partial Factor Productivity of applied N, P & K under maize – wheat cropping system, for SSNM treatment was 37.88 and 35.19, 78.14 and 72.58 & 78.14 and 72.58 kg grain yield per kg N, P and K applied, which was higher than that of NPK treatment (34.57 and 33.01, 60.11 and 57.40 & 62.85 and 60.01 kg grain yield per kg N, P and K applied) with and without incorporation of crop residues, respectively. The agronomic use efficiency of applied N was higher (25.11 - 25.64 kg increase in grain yield per kg applied N) than applied P (24.69 – 27.43 kg increase in grain yield per kg applied P) and followed by applied K (15.77 – 20.34 kg increase in grain yield per kg applied K) in maize-wheat cropping system with and without incorporation of crop residues. With the incorporation of crop residues the nutrient internal use efficiency increased by 3% in wheat but there was not effect of residue incorporation on N internal use efficiency of maize and maize-wheat cropping system. Apparent recovery efficiency of applied N in maize, wheat and maize-wheat cropping system (61.54 – 62.16, 45.97 – 56.87 and 55.64 – 63.15 kg N taken up per kg N applied) was higher than applied P (9.16 – 12.43, 9.58 – 10.45 and 7.83 – 8.57 kg P taken up per kg P applied) and followed by K (84.24 – 89.79, 56.45 – 67.28 and 38.05 – 49.57 kg K taken up per kg K applied).

Bibliometric Analysis of Soil Science as a Scientific Area

It is shown that interdisciplinarity in soil science as a scientific area has been growing ever more rapidly in recent years, while the dissemination of related information over different scientific journals has become excessive and still continues to increase. In particular, the number of Russian journals publishing papers on soil science and represented in the eLIBRARY.ru database increased by more than six times in 14 years (2005–2018) and, by the moment of our study, comprised over 600 names of journals and other Russian-language publications. Since 1997, the segment of papers on soil research has finally shifted from the category of soil science to environmental sciences. The Russian array of publications of 1975–2018 on soil research is analyzed in terms of its positioning in the world. Currently, the number of papers on soil science is actively increasing both in Russia and worldwide. The highest growth rate in the Russian document flow in this scientific area was observed in 2016–2018. In the number of publications, Russian soil science is in a good position in the world. Citation analysis demonstrates an increase in the citation rate in the Web of Science Core Collection (WoS CC) and Scopus databases. Contrary to the widespread opinion on the preferential citation of papers, monographs are prevalently cited in the area of soil science in the eLIBRARY.ru.

Desenvolvimento de um sistema para recomendação de calagem e adubação para as culturas de grãos

As recomendações de calagem e adubação para as diferentes culturas nas principais regiões produtoras do País fundamentam-se no conhecimento gerado por pesquisadores da área de ciências do solo. Tabelas de interpretação para os teores de nutrientes no solo e tabelas com as quantidade de nitrogênio, fósforo e potássio foram elaboradas para os diferentes manuais publicados em alguns estados/regiões. Sob a designação de AGROFERT, foi criado um sistema WEB que tem como objetivo integrar as informações dos sistemas de recomendação de corretivos e fertilizantes para os estados do Rio Grande do Sul/Santa Catariana e Paraná para as principais culturas de grãos e avaliar as evolução das características químicas do solo. O sistema apresenta uma base científica consistente, permitindo recomendações mais abrangentes e passíveis de contínuo aperfeiçoamento. Até o momento os diferentes sistemas de recomendação informatizados existentes são específicos para um único estado/região e trazem informações mais simplórias. O sistema Agrofert possibilita uma economia de tempo, pois seu uso dispensa calcular, corrigir e redigir recomendações pelo método tradicional (Manual).

Surface liming effects on soil radiation attenuation properties

This study investigates the effects of surface liming on soil attenuation radiation properties. For this, measurements of soil chemical attributes (pH, organic carbon, H+Al, Al3+, Ca2+, and Mg2+) and attenuation radiation parameters (mass attenuation coefficient, μm, atomic and electronic cross sections, σa and σe, effective atomic number and electron density, Zeff and Nel) were carried out. This aim was motivated by the fact that possible μm variation might cause as well variation in the determination of soil physical properties. The studied soil, classified as a Dystrudept sity-clay, is located in South Brazil. The trial consisted of five stripes, one of them under pasture and the remaining under no-till system (NTS). Lime rates of 0, 10, 15, and 20 t ha−1 were broadcast on the NTS soil surface. Disturbed soil samples were collected 30 months after liming at the top (0–10 cm) and subsoil (10–20 cm) layers. Soil chemical attributes were characterized following standard experimental procedures. The soil oxide composition, obtained by EDXRF analysis, was used to calculate μm for 241Am and 137Cs photon energies with XCOM computer code. μm values were employed to calculate σa, σe, Zeff, and Nel and to predict variations in soil bulk density (ρ) and total porosity (φ). Surface liming notably increased contents of soil pH, Ca2+, and Mg2+ while reduced H+Al and Al3+ at the top soil layer, where μm, σa, σe, and Zeff were also increased with the lime rates. However, at the subsoil layer, liming neither lessened soil acidity nor induced remarkable changes in the attenuation parameters. When using 137Cs photon energy, incoherent scattering totally dominated over the radiation interaction processes whereas photoelectric absorption and coherent scattering substantially contributed when 241Am photon energy was used. Therefore, the increasing in soil attenuation parameters at the top soil layer was more accentuated considering 241Am than 137Cs photon energy. Variation in μm caused considerable variation in ρ and φ only for 241Am photon energy. The findings regarding the effect of μm variation induced by liming on the determination of soil physical properties are extremely relevant because traditionally, in the soil science area, μm values are calculated without considering any chemical modification to which the soil can be submitted. Bearing in mind that ρ and φ are important parameters from the agricultural and environmental points of view, not representative measurements of μm can lead to biased values of ρ and φ.

Controlling the marginal false discovery rate in inferences from a soil dataset with α‐investment

SummaryLarge datasets on soil provide a temptation to search for relations between variables and then to model and make inferences about them with statistical methods more properly used to test preplanned hypotheses on data from designed experiments or sample surveys. The control of family‐wise error rate (FWER) is one way to improve the robustness of inferences from tests of multiple hypotheses. In its simplest form, hypothesis testing with FWER control lacks statistical power. The α‐investment approach to controlling the marginal false discovery rate is one method proposed to improve statistical power. In this paper I outline the α‐investment approach and then demonstrate it in the analysis of a dataset on the rate of CO2 emission from incubated intact cores of soil from a transect over Cretaceous rocks in eastern England. Hypotheses are advanced after considering the literature and examining relations among the available soil variables that might be proposed as explanatory factors for the variation of CO2 emissions. They are then tested in sequence with α‐investment, such that the rejection of null hypotheses increases the power to reject later ones, while controlling the overall marginal false discovery rate at a specified value. This paper illustrates the use of α‐investment to test a multiple set of hypotheses on a soil dataset; statistical power is improved by ordering the sequence of hypotheses on the basis of process knowledge. The approach could be useful in other areas of soil science where covariates must be selected for predictive statistical models, notably in the development of pedotransfer functions and in digital soil mapping.Highlights α‐investment controls marginal false discovery rate in statistical inference. Hypotheses were advanced about soil factors that affect CO2 emission from soil. These hypotheses were tested in sequence with control of marginal false discovery rate. Soil properties, land use and parent material were significant predictors.

Ecological soil physics as section of ecological soil science

Nowadays, there is a general penetration of ecology in other related sciences. Soil science is not an exception. To the evidence of this, the works of soil scientists may serve, that have appeared recently. It is shown that the ecology of soil is a broader area of the genetic soil science, than ecological soil science. In addition to the doctrine of the ecological functions of soil, modern soil ecology also includes the factor ecology and the doctrine of biosphere soil conservation. In modern soil science there are 2 main areas – fundamental, which aims to study all the features of soil as a natural body, and applied that examines various aspects of soil use by man. At the same time it should be noted that most of soil scientists until recently isolated a genetic soil science in two main areas – the genesis and the geography of soils. Academician L. I. Prasolov (1978) was the first who proposed to allocate soil ecology in a separate section of soil science, along with the above directions. V. R. Volobuev (1963) hold on to the similar views. I. A. Sokolov (1993) showed that the section «Soil ecology» is equal to such sections of soil science as the «Genesis of the soil» and «Geography of the soil». N. A. Gorin (2005) hold on to the similar point of view. On this basis, we offer the following vision of the place of soil ecology in the structure of modern soil science. This scheme is based on the allocation of basic research in the areas of soil science by the team of authors under the leadership of the Moscow State University V. A. Kovda and B. G. Rozanov (Pochvovedenie, 1988). The classification of the historic area of soil science is identified with the genesis of soil by us, and pedography – with the geography of soil. The scientific achievements of other fundamental areas (pedognostika, dynamic soil science, regional soil science, history and methodology of science) are widely used to address key issues of historical soil science and pedography. The structure of the direction «Ecology of soil» is developed by academician G. V. Dobrovolsky and E. D. Nikitin (2012). This doctrine of the ecological functions of soil, classification by B. F. Aparin (2012) is a fundamental direction, the theoretical basis of ecological soil science, related to the applied directions. After L. O. Karpachevsky (2005), who considers the ecological functions of soil subject as ecological soil science, we identify the ecological soil science with the doctrine of the ecological functions of soil in some extent. This view is confirmed by the definition of ecological soil science, formulated G. V. Dobrovolsky and G. S. Kust (2012) – «This is a direction in modern soil science, studied the role of soil as a unique habitat of plants, animals, microorganisms, and especially – in human life, in the functioning of the biosphere and the individual ecosystems». From the above definition, it is clear that in this case, the authors believe that the core of ecological soil science is ecological functions of soil, which manifest themselves through their specific role in nature and human life. The subject of the study of ecological soil science, as indicated by L. O. Karpachevsky (2005), is the ecological functions of soil. Modern physics of soil – is the area of soil science that studies the physical properties of the soil and the place in which physical processes are flowing (Voronin, 1986). As you can see from the definition, the ecological functions of soil caused by the physical properties of soil, remain outside the field of soil physics research. For this reason, there is a need for the provision and the development of ecological soil physics, which is based on theoretical and practical achievements of classical physics of soil, and will also pay close attention to research the ecological functions of soil.

Soils Governance in Australia: challenges of cooperative federalism

This paper analyses soil governance in Australia and the challenges facing sustainable natural resource management within the context of a cooperative system of federation and a globalised market economy. With only 6 per cent of the Australian landmass considered arable, one would assume that protecting Australia’s valuable soil resource would be of national significance. However, Australia currently lacks nationally consistent policies and legal instruments to ensure that its soil is protected, maintained and enhanced for future generations. While recognising that soil governance is a broad discipline encompassing many areas of soil science and management, this discussion will only focus on the soil conservation aspects of sustainable ecosystems and sustainable food and fibre in Australia; it will not explore in depth issues of soil contamination and other pollution related areas. The paper discusses: the state of Australian soils and the managers of these resources; current soil governance in Australia (based on the Food and Agriculture Organisation of the United Nations definition); and a case study example of an Australian state approach to landuse conflict and the protection of agricultural lands. The paper highlights policies and institutional arrangements required for the protection of Australian soil and the very communities that are attempting to steward these resources for future generations.

Profiles in History

1883 1949 Agricultural Map of California, 1883. The origins of the Soil Survey in California trace back beyond the first soil surveys of the US Bureau of Soils in 1899 to the founding of soil science itself. California's Eugene W. Hilgard at the University of California at Berkeley was a pioneer in many areas of soil science and is referred to as the cofounder of soil science by Hans Jenny and others. Hilgard also developed an original vision for soil surveys in California. A Conservation Survey of Stanford University's Agricultural Lands in 1949. The first soil survey map produced in California depicts the agricultural soil regions of the state. Shown here as “Agricultural Map of California,” this product was “compiled from many sources by R.H. Loughridge, Ph.D., Special Agent, under the direction of Eug. W. Hilgard, Ph.D., Special Agent in charge of cotton production” in 1883. The map was in essence a depiction of major land resource areas (MLRAs) in the state. Hilgard speculated that California's Great Central Valley would be good for growing cotton and was in charge of helping develop cotton production the state. This generalized map depicts the marsh and tule lands in the Delta and along rivers in light green. The alluvial lands of the Great Central Valley are shown in medium green. Note the lakes in the southern part of the valley at the time, which no longer exist today. Prominent adobe lands are shown in dark brown, lower Sierra foothills in red, the upper Sierra foothills in light pink, and the Sierra Nevada Mountains in dark pink. The Coast Ranges are in orange-brown with their chief valleys in yellow. The deserts are in light tan. Dark green areas depict redwood forests. The marsh lands around the San Francisco bay are not identified, possibly because they were too small in scale. The map displays remarkable knowledge of the soils and landforms of California for 1883. Contributed by Terry D. Cook and William R. Reed, Professional Soil Scientists Association of California. The formation of the USDA-Soil Conservation Service (SCS) under the New Deal in 1935 brought many changes to the Soil Survey in California. SCS set up headquarters for California and Nevada in Berkeley, CA and hired Dr. Stanley Cosby from the university to be the Regional Soil Scientist. Leonard Wholetz was hired as his assistant. One of his first assignments was a demonstration project in Santa Paula where erosion was severe. Many similar projects using conservation surveys would be produced through the early 1950s. The SCS quickly changed to making conservation needs surveys from standard soil surveys. These were quickly done and delivered to the conservationists for immediate use. The surveys were generally small areas with severe erosion problems. Twelve Civilian Conservation Corps camps were set up in California to implement conservation practices. Most were in central and southern California and in coastal areas. Many soil scientists went to work for the SCS. The work of the UC Division of Soils and the Bureau of Chemistry and Soils continued standard soil surveys, but there were fewer areas mapped than in the 1920s. The map shown here is one of the few remaining conservation maps from California. It included the Stanford University property and was made to assist Stanford in management of the lands. Soil depth, slope, erosion level, and capability unit were the extent of the information gathered. It was rapidly assembled and put to use immediately. From 1935 to 1952 there were likely thousands of these conservation maps made in California alone. They were used extensively to control serious erosion, mostly on private lands. Apparently an order was sent out by SCS around 1960 to dispose of them. Very few conservation maps remain, and the ones that do remain are maps of larger areas like this one at Stanford University. It was bound in a small book, rather than as a loose map, allowing it incidentally to survive on a shelf with other materials. Contributed by Terry D. Cook and William R. Reed, Professional Soil Scientists Association of California.

Teaching soil science: strategies and guarantees for the future .

The aim of the current work was to propose an approach to the interdisciplinary teaching of science that would generally increase interest in the study and knowledge of science, and more specifically in the area of soil science. The paper outlines how this pedagogical proposal was carried out in two schools, working with children studying the 5th and 6th courses of Primary Education. This was achieved through a methodological process that made it possible to both rank children’s knowledge from basic to complex, and to pedagogically organise the whole action using the same procedure. The approach was used to establish the different stages of knowledge construction, whose levels were increasingly complex in terms of relationships, thereby drawing nearer to a perception of the systematic reality of the Earth and helping students to understand that soil is a natural resource that is essential to life. This paper presents qualitative information corresponding to the periods before and after the pedagogical intervention, and details how the children in the 5th and 6th grades of Primary Education at two different schools conceptualise soil. The paper also presents the way in which they perceive the relationship between soil and its immediate environment. The impact of the pedagogical proposal was assessed through comparisons between the children from the working and control groups which were based on differences in the assimilation of concepts relating to the soil system. The results clearly show that when applying the proposed educational approach, it was possible for the work groups to achieve a more complex construction of knowledge relating to the establishment and functions of the soil concept.

Three-dimensional interpolation of soil data: fertility and pedomorphological features in southern Brazil

The graphical representation of spatial soil properties in a digital environment is complex because it requires a conversion of data collected in a discrete form onto a continuous surface. The objective of this study was to apply three-dimension techniques of interpolation and visualization on soil texture and fertility properties and establish relationships with pedogenetic factors and processes in a slope area. The GRASS Geographic Information System was used to generate three-dimensional models and ParaView software to visualize soil volumes. Samples of the A, AB, BA, and B horizons were collected in a regular 122-point grid in an area of 13 ha, in Pinhais, PR, in southern Brazil. Geoprocessing and graphic computing techniques were effective in identifying and delimiting soil volumes of distinct ranges of fertility properties confined within the soil matrix. Both three-dimensional interpolation and the visualization tool facilitated interpretation in a continuous space (volumes) of the cause-effect relationships between soil texture and fertility properties and pedological factors and processes, such as higher clay contents following the drainage lines of the area. The flattest part with more weathered soils (Oxisols) had the highest pH values and lower Al3+ concentrations. These techniques of data interpolation and visualization have great potential for use in diverse areas of soil science, such as identification of soil volumes occurring side-by-side but that exhibit different physical, chemical, and mineralogical conditions for plant root growth, and monitoring of plumes of organic and inorganic pollutants in soils and sediments, among other applications. The methodological details for interpolation and a three-dimensional view of soil data are presented here.

Helping Cities Manage Stormwater Runoff: A Day in the Life of Bill Shuster

Helping Cities Manage Stormwater Runoff: A Day in the Life of Bill Shuster

Institutional landmarks in Brazilian research on soil erosion: a historical overview

The problem of soil erosion in Brazil has been a focus of agricultural scientific research since the 19th century. The aim of this study was to provide a historical overview of the institutional landmarks which gave rise to the first studies in soil erosion and established the foundations of agricultural research in Brazil. The 19th century and beginning of the 20th century saw the founding of a series of institutions in Brazil, such as Botanical Gardens, executive institutions, research institutes, experimental stations, educational institutions of agricultural sciences, as well as the creation and diversification of scientific journals. These entities, each in its own way, served to foster soil erosion research in Brazil. During the Imperial period (1808-1889), discussions focused on soil degradation and conserving the fertility of agricultural land. During the First Republic (1889-1930), with the founding of various educational institutions and consolidation of research on soil degradation conducted by the Agronomic Institute of Campinas in the State of São Paulo, studies focused on soil depletion, identification of the major factors causing soil erosion and the measures necessary to control it. During the New State period (1930-1945), many soil conservation practices were developed and disseminated to combat erosion and field trials were set up, mainly to measure soil and water losses induced by hydric erosion. During the Brazilian New Republic (1945-1964), experiments were conducted throughout Brazil, consolidating soil and water conservation as one of the main areas of Soil Science in Brazil. This was followed by scientific conferences on erosion and the institutionalization of post-graduate studies. During the Military Regime (1964-1985), many research and educational institutions were founded, experimental studies intensified, and coincidently, soil erosion reached alarming levels which led to the development of the no-tillage system.

Fertilidade do solo e nutrição de tangerineiras ‘Ponkan’ manejados com resíduos sólidos e adubação química

O objetivo do trabalho foi avaliar alguns atributos químicos do solo e o estado nutricional das tangerineiras ‘Ponkan’ no solo manejado com resíduos orgânicos e adubação química. O experimento foi conduzido no Departamento de Recursos Naturais/Ciência do Solo - FCA/UNESP em Botucatu, SP. As mudas de tangerineira foram plantadas e manejadas com lodo de esgoto (LE), esterco de curral curtido (EC) e adubação química (AQ). Os resultados permitiram concluir que houve um aumento significativo nos teores dos atributos CTC, MO, N-total P e K, no solo manejado com resíduo orgânico. A aplicação do lodo de esgoto também não prejudicou a qualidade do solo pois a adição dos elementos As, Cd, Cr e Hg em sua constituição, não foi significativa. O manejo do solo com os resíduos proporcionou um aumento significativo no teor de N, P, Ca e S nas folhas das tangerineiras ‘Ponkan’ e, ao mesmo tempo, esses resíduos não contribuíram para um aumento significativo do teor foliar dos micronutrientes B, Cu, Fe, Mn e Zn nem dos elementos As, Cd, Cr e Pb. O manejo do solo com lodo de esgoto não resultou em aumento significativo dos elementos As, Cd, Cr e Hg nas folhas e nos frutos.

A Noninvasive Resonance-Based Method for Moisture Content Evaluation Through Microstrip Antennas

Several techniques for measuring the moisture levels of materials, particularly in the soil science area, are available. Nevertheless, the state of the art is rather lacking in moisture-sensing methods that are both inexpensive and noninvasive. The time-domain reflectometry (TDR)-based method, despite being a well-established low-cost technique for sensing moisture content, is intrinsically invasive due to the configuration of the probes that are commonly used. These considerations motivated the authors to investigate the adoption of simple inexpensive microstrip antennas as sensing elements for TDR-based moisture content measurements. For this purpose, the water content of the monitored material is sensed through the changes in the reflection scattering parameter S 11(f) of the antenna. In particular, the change in the resonant frequency of the antenna, which is evaluated through an appropriate processing of the TDR waveforms, is correlated with the water content of the material under investigation. The ultimate goal is to assess a sensing method that can be implemented for inexpensive real-time noninvasive monitoring applications.

Relationships between soil respiration and soil moisture

The interaction of soil microbes with their physical environment affects their abilities to respire, grow and divide. One of these environmental factors is the amount of moisture in the soil. The work we published almost 25 years ago showed that microbial respiration was linearly related to soil-water content and log-linearly related to water potential. The paper arose out of collaboration between two young researchers from different areas of soil science, physics and microbiology. The project was driven by not only our curiosity but also the freedom to operate without the constraints common to the current system of science management. The citation history shows three peaks, 1989, 1999 and from 2002 to the present day. Interestingly, the annual citation rate is as high as it has ever been. The initial peak is due to the application of the work to studies on microbial processes. The second peak is associated with the rise of simulation modelling and the third with the relevance of the findings to climate change research. In this article, our paper is re-evaluated in the light of subsequent studies that allow the principle of separation of variables to be tested. This re-evaluation lends further credence to the linear relationship proposed between soil respiration and water content. A scaled relationship for respiration and water content is presented. Lastly, further research is suggested and more recent work on the physics of gas transport discussed briefly.

Spatial Prediction of Heavy Metal Pollution for Soils in Peri-Urban Beijing, China Based on Fuzzy Set Theory

ABSTRACT Fuzzy classification combined with spatial prediction was used to assess the state of soil pollution in the peri-urban Beijing area. Total concentrations of As, Cr, Cd, Hg, and Pb were determined in 220 topsoil samples (0–20 cm) collected using a grid design in a study area of 2600 km 2 . Heavy metal concentrations were grouped into three classes according to the optimum number of classes and fuzziness exponent using the fuzzy c -mean (FCM) algorithm. Membership values were interpolated using ordinary kriging. The polluted soils of the study area induced by the measured heavy metals were concentrated in the northwest corner and eastern part, especially the southeastern part close to the urban zone, whereas the soils free of pollution were mainly distributed in the southwestern part. The soils with potential risk of heavy metal pollution were located in isolated spots mainly in the northern part and southeastern corner of the study region. The FCM algorithm combined with geostatistical techniques, as compared to conventional single geostatistical kriging methods, could produce a prediction with a quantitative uncertainty evaluation and higher reliability. Successful prediction of soil pollution achieved with FCM algorithm in this study indicated that fuzzy set theory had great potential for use in other areas of soil science.