L.C. Timm

L.C. Timm
Universidade Federal de Pelotas | UFPEL · Rural Engineering

About

161
Publications
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1,879
Citations
Citations since 2016
70 Research Items
1216 Citations
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250

Publications

Publications (161)
Article
Full-text available
Soil hydraulic properties are essential for modeling and evaluating several soil-water processes. The use of pedotransfer functions (PTFs) is a viable alternative in the analysis of these processes due to the high costs or difficulty in measuring these properties. We aimed to (1) examine the performance of a physically-based PTF and a pool of empir...
Article
The objective was to develop efficient substrates, with increasing proportions of biochar derived from anaerobic sewage sludge (ASS-biochar) and regionally available raw materials, to produce tobacco seedlings (Nicotiana tabacum) in floating systems. Physical, hydraulic and chemical variables and the effects on tobacco plants were evaluated through...
Article
The adoption of different row spacing configurations has been advocated as a possible solution to mitigate the problems related to soil compaction in sugarcane areas due to the frequent use of heavy agricultural machines. This study aimed to (i) identify factors that influence the relationships of biometric attributes of sugarcane and attributes of...
Article
This work aimed to analyze the average temperature and rainfall in the Southern and Steppe regions of the State of Rio Grande do Sul, Brazil, obtained by three global climate models regionalized by the Eta model (CANESM2, HADGEM2-ES and MIROC5) for the historical period, and two future climate scenarios (RCP 4.5 and RCP 8.5), subdivided into three...
Article
The use of irrigation systems in rice and other crops cultivated under aerobic conditions in lowland leveling soils has increased worldwide. This study aimed to evaluate the impact of land leveling operations on the soil physical quality (SPQ), mainly on water retention and aeration in a lowland soil in Southern Brazil. A 10 × 10 m-grid was establi...
Article
Saturated soil hydraulic conductivity (Ksat) and soil moisture content (Θ) are key soil hydraulic properties for the understanding of hydrological processes at the watershed scale. Previous approaches in the use of Ksat to describe hydrological processes have mainly applied standardized or derived Ksat values, although the high spatial variability...
Article
Full-text available
The high spatial variability of the saturated soil hydraulic conductivity (Ksat) and the effort required for its data sampling have been a challenge for soil scientists to obtain its representativeness at a scale resolution required by watershed management. The objective of this work was to simulate the spatial variability of Ksat and evaluate its...
Article
Full-text available
The assessment of soil attributes affected by land use changes or different cultivation management strategies is commonly based on a comparison between agricultural fields, neglecting the natural soil spatial variability. This study aimed to develop a methodology based on improved space series to differentiate between spatial variability of soil at...
Article
Full-text available
Denitrification and NH3 volatilization are the main removal processes of nitrogen in coastal saline soils. In this incubation study, the effects of wheat straw biochar application at rates of 0, 2, 5, 10 and 15% by weight to saline soil with two salt gradients of 0 and 1‰ on denitrification and NH3 volatilization were investigated. The results show...
Article
Soil friability (F) is one of the key indicators of soil structural conditions and can be used to assess the environmental impacts of different tillage and no-tillage practices on crop growth and yield. F can be affected by several driving factors such as soil (physical and chemical parameters) and topographic attributes and different land uses as...
Preprint
Full-text available
The assessment of soil attributes affected by land use changes or different cultivation management strategies is commonly based on a comparison between agricultural fields, neglecting the natural soil spatial variability. This study aimed to develop a methodology based on improved space series to differentiate between spatial variability of soil at...
Article
Full-text available
The objective of this study was to evaluate substrates formulated with proportions of sewage sludge (SS)-solarized and SS-biochar in the production of seedlings of two indicator crops: lettuce (Lactuca sativa L.) and black wattle (Acacia decurrens Wild). The study was composed of two experiments conducted in greenhouse, in randomized block designs....
Article
Full-text available
HYDRO-PHYSICAL CHARACTERISTICS OF SUBSTRATES FOR LETTUCE PRODUCTION IN FLOATING GROWTH SYSTEM ALEX BECKER MONTEIRO1; IVAN DOS SANTOS PEREIRA2; ADILSON LUÍS BAMBERG3; CRISTIANE MARILIZ STÖCKER4; PABLO LACERDA RIBEIRO5 E LUÍS CARLOS TIMM6 1Departamento de Solos, Universidade Federal de Pelotas, Campus Universitário, s/n, CEP 96160-000, Pelotas, Rio G...
Article
The aim of this study was to determine the impact of harvesting traffic by evaluating the spatial variability of soil physical attributes on a clayey Oxisol under sugarcane cultivation using different row spacing. Two areas of sugarcane production (RB855156 genotype) were planted in autumn 2013, both using conventional planting systems. Treatments...
Article
Saturated soil hydraulic conductivity (Ksat) is a key factor in hydrological management projects and its variability along the landscape hinders its correct use in the formulation of such projects. Ksat varies under different climatic and hydrological conditions at spatial scales as reported in several studies. However, co-regionalization of Ksat r...
Article
Full-text available
Land leveling is used to correct soil surface irregularities to improve surface drainage and irrigation. It also makes the area more manageable for an array of agricultural activities such as planting and harvesting. The objective of this work was to evaluate two designs of land forming, one aimed at optimizing drainage and the other at optimizing...
Article
Full-text available
The state-space approach is used to describe surface soil water content and temperature behaviour, in a field experiment in which sugarcane is submitted to different management practices. The treatments consisted of harvest trash mulching, bare soil, and burned trash, all three in a ratoon crop, after first cane harvest. One transect of 84 points w...
Article
Knowledge on multi-scale and localized control of saturated soil hydraulic conductivity (Ksat) at the watershed scale is lacking. The objective of this study was to evaluate the multi-scale spatial relationships among Ksat and environmental factors (i.e., soil and topographic attributes and land-use systems) using wavelet coherency and multiple wav...
Article
The mapping of saturated soil hydraulic conductivity (KSat) is essential to understanding soil water dynamics and is a sensitive input in hydrological modeling. The objectives of this study were to provide a reference for the selection of soil hydrology and other environmental attributes that can be used as covariates for estimating KSat and to com...
Article
Land-leveling is used to correct soil surface irregularities to improve surface drainage and irrigation. It also makes the area more manageable for an array of agricultural activities such as planting and harvesting. The objective of this work was to evaluate two designs of land-forming, one aimed at optimizing drainage and the other at optimizing...
Article
Efficient water use in agriculture is a global demand, and in this context, the implementation of a sprinkler irrigated rice system has become a reality. Besides saving water, proper management of a sprinkler irrigated system can maintain high levels of productivity. This study aimed to determine the effect of soil water tension on rice crop produc...
Article
Full-text available
A avaliação isolada das variáveis limnológicas visando ao monitoramento de um manancial não permite obter uma visão global da dinâmica que ocorre no corpo hídrico. Diante disso, esse trabalho teve como objetivo adequar um Índice de Qualidade de Água para o rio Camaquã, localizado no sul do Rio Grande do Sul, utilizando para isso dados secundários d...
Chapter
Spatial and temporal variability of attributes of the soil–plant–atmosphere system is analyzed in this chapter based on the classical statistics of Fisher and on geostatistics. Several specific concepts are introduced, like the sampling transects or grids. It is shown that the classical statistics and geostatistics complement each other. Mean or av...
Chapter
The infiltration of water into soils is first studied for homogeneous soils for a better understanding of the process, and later cases of heterogeneous soils are introduced in the discussion. The simplest case, horizontal infiltration, is studied analytically with the solution of differential equations that govern the process. Basic concepts are in...
Chapter
Heat flow is shown to mainly be due to diffusion in soils. Diffusion is also called conduction and is the process by which solar radiation is propagated downward inside the soil profile. Fick’s equation for heat flow is described in terms of temperature gradients and thermal conductivities. Soil heat diffusivity is also used to explain temperature...
Chapter
The state of equilibrium of water in the Soil-Plant-Atmosphere System (SPAS) is essential for the understanding of the dynamic processes that occur in the system, which will be dealt in the chapters to come. We introduce thermodynamic concepts to the state of water in a universal form, with a physical understanding for agronomists, environmentalist...
Chapter
Gas movement is studied in the soil showing that the diffusion process is the main one commanding the process. Diffusion is described by Fick’s law, using the partial gas pressure component as responsible for the gradient. Some examples of solution of boundary value problems (BVP) are presented to illustrate the processes responsible for soil aerat...
Chapter
Soil is the central part of Soil–Plant–Atmosphere System (SPAS), being the second subsystem of the SPAS described in this book. The soil is characterized by its three components, the solid particles that are the main structural body, the soil water described as a solution of plant nutrients, and the soil air that is essential in the gas transfer be...
Chapter
The water vapor losses from the soil to the atmosphere is analyzed in this chapter. It is shown that these processes are strongly dependent on the available energy that comes from the atmosphere: the solar energy. Most of the concepts like evaporation equivalent, soil water evaporation, evapotranspiration, potential evapotranspiration, and crop eva...
Chapter
This chapter studies mainly the redistribution of rain or irrigation waters in the soil profile. It is shown that the main difficulty in the mathematical analysis is the hysteresis, because during the redistribution of water, part of the profile is under a wetting process and another part under a drying process. The most important methods for the d...
Chapter
The three processes that are responsible for nutrients from the soil reach the plant root system: diffusion, mass transport, and root interception. They are here presented and discussed in detail. The influence of soil physical conditions on the absorption of nutrients is shown for soil water content, temperature, soil aeration, and root developmen...
Chapter
The movement of water is explained in detail through Darcy-Buckingham’s law. For this, the concepts of flow, gradient, and conductivity are explained and illustrated with practical examples. Special emphasis is given to the hydraulic conductivity, explaining the most common forms of its presentation. The saturated and the unsaturated flows of water...
Chapter
Initiating studies on the physical behavior of the Soil–Plant–Atmosphere System (SPAS), it is essential to show aspects of how MAN interacts with the elements of this system. The SPAS is a dynamic system and has both closed and open characteristics at the same time. It is an articulated set of interrelationships between the parts of a whole that se...
Chapter
Water absorbed by plants depends on its availability in the soil reservoir. Therefore the soil reservoir is studied in relation to its available water capacity, which depends on the field capacity and on the permanent wilting point. Approaches on water availability are presented in function of the soil water potential, derived from the Gibbs free e...
Chapter
The soil solution is first presented at equilibrium, introducing the concepts of Gibbs free energy, ion activity, activity coefficients, activity of ionic solutions and ionic strength. The Donnan theory for colloids in suspension and the double ionic layer of clay minerals in soils are very well described, to introduce the concepts of cation exchan...
Chapter
Spatial and temporal variability of the soil-plant-atmosphere system is an important tool for the statistical analysis of several sets of data collected in the field. The techniques here seen allow the scientist to reveal characteristics of systems that cannot be analyzed by classical statistics methods. Various tools are presented, like the cross-...
Chapter
Water is treated as the universal solvent in the Soil–Plant–Atmosphere System (SPAS), being the first subsystem of the SPAS. Water is physically and chemically defined through its main characteristics needed for the description of the phenomena that occur in the SPAS. Discussion is made on water properties that make it an excellent solvent for ioni...
Chapter
Units, their characterization and their transformation into other system, are essential for all chapters seen in this book. For example, how to transform g of dry matter per plant into tons per hectare? Dimensional analysis takes care of these problems, and here we give you a general overview of how to understand units and their dimensions, and how...
Chapter
This chapter describes the third subsystem of the Soil–Plant–Atmosphere System (SPAS). As the title indicates, the plant is here described in order to understand the processes that involve the conversion of solar energy into the different products of plant dry matter. Photosynthesis, respiration, growth, and development are studied from the agricul...
Chapter
The fourth subsystem of the Soil–Plant–Atmosphere System (SPAS), described in this book, is the Atmosphere. For the purposes of this book, the water vapor and the solar radiation are the main subjects related to crop production. After discussing the composition and the structure of the atmosphere, water vapor is treated in detail giving the basis f...
Chapter
The complete and direct water balance for agricultural and natural systems is presented in detail, discussing all components: rainfall, irrigation, runoff, evapotranspiration, drainage below the root zone, and, finally, the changes of soil water content as a function of depth and time close the balance. Evaluation of soil erosion is presented in co...
Book
This textbook presents the concepts and processes involved in the soil-plant-atmosphere system as well as its applications in the water cycle in agriculture. Although reaching the frontier of our knowledge in several subjects, each chapter starts at the graduation level and proceeds to the post-doctoral level. Its more complicated subjects, as math...
Article
Studies focusing on the impact of levelling on the management of available water for rice growth and on soil hydro‐physical quality indicators cultivated in lowland soils under aerobic conditions are still scarce. The objective of this study was to evaluate the levelling impact on soil water retention and soil quality indicators by multivariate and...
Article
Full-text available
Avaliou-se o efeito da retenção de água de substratos para plantas formulados a partir de diferentes proporções de lodo de esgoto (LETE) solarizado, na produção de mudas de acácia-negra (Acacia mearnsii). O experimento foi conduzido em casa de vegetação e no Laboratório de Física do Solo da Embrapa Clima Temperado. O LETE utilizado foi coletado em...
Article
Full-text available
INFLUENCE OF IRRIGATION AND SOIL TEXTURE IN THE GROWTH OF PEACH TREE BRANCHES AND FRUITS OF cv. ESMERALDA1 ALEX BECKER MONTEIRO2; LUÍS CARLOS TIMM3; CARLOS REISSER JÚNIOR4; LUCIANO RECART ROMANO5 E MARCOS TOEBE6 1 Part of Master’s Dissertation of the first author. 2 Departamento de Solos, Universidade Federal de Pelotas, Campus Universitário, s/n,...
Article
Full-text available
Probability distribution functions (PDF) have been used for decades to model the applied water depth by irrigation equipment; however, there are few studies that evaluate the PDF goodness-of-fit to mechanical lateral-move irrigation system water application, especially with oscillating plate sprinklers. The objectives of this study with a lateral-m...
Article
Many of the traditionally used hydrological models have complex formulations and require several input variables over time and space, which are generally scarce and expensive for obtaining, especially in developing countries. In order to overcome these limitations, the Lavras Simulation of Hydrology has been developed and successfully applied to Br...
Article
Full-text available
Soil erosion is currently one of the main concerns in agriculture, water resources, soil management and natural hazards studies, mainly due to its economic, environmental and human impacts. This concern is accentuated in developing countries where the hydrological monitoring and proper soil surveys are scarce. Therefore, the use of indirect estimat...
Article
Full-text available
The West African Economic and Monetary Union (abbreviated as UEMOA from its name in French: Union Économique et Monétaire Ouest-Africaine) is an organization of eight West African countries: Benin, Burkina Faso, Ivory Coast, Guinea-Bissau, Mali, Niger, Senegal and Togo. This region suffers an agricultural yield gap mainly due to misplanning of crop...
Article
Full-text available
CONSTRUÇÃO E AVALIAÇÃO DE UMA TURBINA "TIPO PELTON" Luís Carlos TimmLaboratório Física do Solo, Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, CP. 96, CEP: 13416-000. E-mail: lctimm@cena.usp.brTamara Maria GomesRoberto Terumi AtarassiTarlei Arriel Botrel Departamento de Engenharia Rural, Escola Superior de Agri...
Article
Full-text available
Soil water content is a key property in the study of water available for plants, infiltration, drainage, hydraulic conductivity, irrigation, plant water stress and solute movement. However, its measurement consumes time and, in the case of stony soils, the presence of stones difficult to determinate the water content. An alternative is the use of p...
Article
Full-text available
The use of water potential indicators in the plant has been adopted in irrigation management, in recent years, since it is accepted that the plant is the best indicator of its own water status. The objective of this study was to verify the relationship between water potential in peach tree branches and the evaporative demand of the atmosphere and t...
Article
Full-text available
In the lowlands of Rio Grande do Sul, land leveling is mostly carried out with no slope for the purpose of rice production. In this environment, soils with a low hydraulic conductivity are predominant owing to the presence of a practically impermeable B-horizon near the surface. Land leveling leads to soil accommodation resulting in the formation o...
Article
Full-text available
Soil salinity is a severe worldwide environmental problem that adversely affects soil properties and the crop growth such as okra. We hypothesized that biochar soil amendments could increase the okra salt threshold, alleviate salt stress and improve soil productivity. In this study, a pot experiment was conducted to investigate whether biochar coul...
Article
Full-text available
The objective of this study was to determine the variability of the head loss as a function of the emitter geometry as well as to develop a relation between local head loss caused by the emitter insertion and geometric characteristics of the emitter pipe, using index of obstruction for dripper pipes with non-coaxial emitters. For this, an experimen...
Article
Biochar soil amendments have the potential to improve the soil water and nutrient status, and could enhance crop productivity. A greenhouse experiment was conducted over two consecutive growing seasons to investigate the effects of biochar amendment (BA) in combination with deficit irrigation (DI) on tomato growth, physiology, yield, fruit quality,...
Article
Full-text available
5 Docente do PPG em Recursos Hídricos e do PPG em Manejo e Conservação do Solo e da Água Resumo A textura do solo é um dos principais parâmetros utilizados como indicadores de qualidade física do solo, através da sua determinação é possível inferir sobre outros parâmetros, além de compreender o comportamento e manejo do solo, importantes para a pro...
Article
Soil hydraulic properties are important to the understanding and modeling of hydrological processes at the watershed scale. These properties are presumed to be correlated with associated topographic attributes and other soil factors operating at different intensities and scales. Using multivariate empirical mode decomposition (MEMD), this study exa...
Article
In order to develop models for representation of Christiansen’s Uniformity (CU) and Distribution Uniformity (DU) as a function of wind speed, 32 in-field tests evaluating a mechanical lateral-move irrigation system, used in rice production, were carried out in southern Rio Grande do Sul, Brazil. These tests were used to generate two third-order pol...
Article
Full-text available
Para avaliar um manancial procura-se utilizar ferramentas que diminuam os custos com análises laboratoriais, avaliem simultaneamente múltiplas variáveis de qualidade da água e possibilitem interpretar mais facilmente os resultados das análises laboratoriais. Diante disto objetivou-se aplicar a técnica de agrupamento visando reduzir o número de vari...
Article
Full-text available
The objective of this work was to determine the effect of soil water tension and physicochemical soil attributes on sprinkler-irrigated rice yield in lowlands of the state of Rio Grande do Sul, Brazil. In the 2011/2012 crop season, the effects of 20 and 40 kPa soil water tensions throughout the crop cycle were evaluated, as well as of 40 and 20 kPa...
Article
Full-text available
A similarity hypothesis recently presented to describe horizontal infiltration into homogeneous soils, developed for coarse-textured soils like sieved marine sand, implies that the soil water retention function θ(h) is the mirror image of an extended Boltzmann transform function θ(λ2). A second hypothesis applicable to vertical infiltration suggest...
Article
High spatial variability of soil salinity in coastal reclamation regions makes it difficult to obtain accurate scale-dependent information. The objectives of this study were to describe the spatial patterns of saline-sodic soil properties (using soil pH, electrical conductivity (EC1:5) and sodium ion content (SIC) as indicators) and to gain knowled...
Article
The objective of this study was to evaluate, based on a data-scarce basin in southern Brazil, the potential of the Lavras Simulation of Hydrology (LASH) for estimating daily stream flows, annual streamflow indicators and flow-duration curve. It was also used to simulate the different runoff components and their consistency with the basin physiograp...