Download or read book Simulation of Field Water Use and Crop Yield written by R. A. Feddes and published by Halsted Press. This book was released on 1978-01-01 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theory of field water use: basics of water flow i unsaturated soils;water uptake by plants roots;numerical approximation of flow in soil-root systems. Theory of crop production:mathematical description of growts;water and actual production;calculation of potential production. Theprogram:program for field water use, SWATR;program for crop production,CROPR;execution of SWATR; execution of CROPR.
Download or read book Modeling Root Water Uptake written by Parikshit Verma and published by . This book was released on 2013 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Root water uptake by plants mediates the exchange of water, carbon and energy between land surface and atmosphere and is important in hydrological, climatological, agricultural and ecological studies. Field measurements show that root water uptake could be significantly affected by root water compensation and hydraulic redistribution. We thus use a root water uptake model able to describe these two mechanisms and show their importance when vegetation is growing in shallow water-table environments or duplex soils. The model is based on the Richards equation for the water-flow in soils, with a term for root water uptake being a function of the water potential difference between root xylem and the soil. We describe the flow in the xylem using the Darcy's equation.The model is used in three studies aimed at highlighting the role that root water compensation and hydraulic redistribution might have on the overall root water uptake. In the first study, the model in one dimension is applied to a site near Sydney, Australia, to investigate how native trees growing on duplex soils are able to sustain transpiration rate despite long periods with little or no rain. The model was able to reproduce sap-flux data and the pattern of soil, root and leaf water potential for several months. Scenarios with different root depths showed that trees were able to adjust their water-uptake rates from different soil layers based on soil moisture availability; thus, root water compensation appears to be a key mechanism to maintain sustained transpiration rates. In a second study we investigated the contribution of root water compensation and hydraulic redistribution to root water uptake in shallow water-table environments. We compared the results of our model with a more commonly used root water uptake model. In the third study, we extended the 1D-model to two dimensions, thereby being able to simulate horizontal hydraulic redistribution and the interaction between species with different root systems. In the 2D-model, the roots were assumed to be a continuum in soil and the root systems were described in terms of xylem conductivity fields. Scenarios are presented to show that the 2D-model is able to reproduce observed flow patterns through roots in parts of the soil with different degrees of moisture. The studies presented in this thesis show the further development and use of a modeling approach that is gaining increasing interest in the recent literature. These studies present a realistic description of the role that root water compensation and hydraulic redistribution play in plant water use. The 2D-model introduces a representation of the root system that allows for modelling vertical (hydraulic lift) and horizontal hydraulic redistribution of water in soil, and an efficient description of the interaction between species with different root systems.
Download or read book Modelling Crop weed Interactions written by Martin J. Kropff and published by Int. Rice Res. Inst.. This book was released on 1993 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: General introduction; Empirical models for crop-weed competition; Eco-physiological models for crop-weed competition; Mechanisms of competition for light; Mechanisms of competition for water; Mechanisms of competition for nitrogen; Eco-physiological characterization of the species; Understanding crop-weed interaction in field situation; The impact of environmental and genetic factors; Practical applications.
Download or read book Roots written by Jun J. Abe and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: The root is the organ that functions as the interface between the plant and the earth environment. Many human management practices involving crops, forests and natural vegetation also affect plant growth through the soil and roots. Understanding the morphology and function of roots from the cellular level to the level of the whole root system is required for both plant production and environmental protection. This book is at the forefront of plant root science (rhizology), catering to professional plant scientists and graduate students. It covers root development, stress physiology, ecology, and associations with microorganisms. The chapters are selected papers originally presented at the 6th Symposium of the International Society of Root Research, where plant biologists, ecologists, soil microbiologists, crop scientists, forestry scientists, and environmental scientists, among others, gathered to discuss current research results and to establish rhizology as a newly integrated research area.
Download or read book Comparison of the Root Water Uptake Term of Four Simulation Models written by Peter Willigen and published by . This book was released on 2011 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Climate Change and Terrestrial Ecosystem Modeling written by Gordon Bonan and published by Cambridge University Press. This book was released on 2019-02-21 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides an essential introduction to modeling terrestrial ecosystems in Earth system models for graduate students and researchers.
Download or read book Unsaturated zone Modeling written by R.A. Feddes and published by Springer Science & Business Media. This book was released on 2004-10-11 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mankind has manipulated the quantity and quality of soil water for millennia. Food production was massively increased through fertilization, irrigation and drainage. But malpractice also caused degradation of immense areas of once fertile land, rendering it totally unproductive for many generations. In populated areas, the pollutant load ever more often exceeds the soil’s capacity for buffering and retention, and large volumes of potable groundwater have been polluted or are threatened to be polluted in the foreseeable future. In the past decades, the role of soil water in climate patterns has been recognized but not yet fully understood. The soil-science community responded to this diversity of issues by developing numerical models to simulate the behavior of water and solutes in soils. These models helped improve our understanding of unsaturated-zone processes and develop sustainable land-management practices. Aimed at professional soil scientists, soil-water modelers, irrigation engineers etc., this book discusses our progress in soil-water modeling. Top scientists present case studies, overviews and analyses of strengths, weaknesses, opportunities and threats related to soil-water modeling. The contributions cover a wide range of spatial scales, and discuss fundamental aspects of unsaturated-zone modeling as well as issues related to the application of models to real-world problems.
Download or read book Root Zone Water Quality Model written by Lajpat Ahuja and published by Water Resources Publication. This book was released on 2000 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication comes with computer software and presents a comprehensive simulation model designed to predict the hydrologic response, including potential for surface and groundwater contamination, of alternative crop-management systems. It simulates crop development and the movement of water, nutrients and pesticides over and through the root zone for a representative unit area of an agricultural field over multiple years. The model allows simulation of a wide spectrum of management practices and scenarios with special features such as the rapid transport of surface-applied chemicals through macropores to deeper depths and the preferential transport of chemicals within the soil matrix via mobile-immobile zones. The transfer of surface-applied chemicals (pesticides in particular) to runoff water is also an important component.
Download or read book Soil Physics with Python written by Marco Bittelli and published by . This book was released on 2015 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: This innovative study presents concepts and problems in soil physics, and provides solutions using original computer programs. It provides a close examination of physical environments of soil, including an analysis of the movement of heat, water and gases. The authors employ the programminglanguage Python, which is now widely used for numerical problem solving in the sciences. In contrast to the majority of the literature on soil physics, this text focuses on solving, not deriving, differential equations for transport. Using numerical procedures to solve differential equations allowsthe solution of quite difficult problems with fairly simple mathematical tools. Numerical methods convert differential into algebraic equations, which can be solved using conventional methods of linear algebra. Each chapter introduces a soil physics concept, and proceeds to develop computer programsto solve the equations and illustrate the points made in the discussion.Problems at the end of each chapter help the reader practise using the concepts introduced. The text is suitable for advanced undergraduates, graduates and researchers of soil physics. It employs an open source philosophy where computer code is presented, explained and discussed, and provides thereader with a full understanding of the solutions. Once mastered, the code can be adapted and expanded for the user's own models, fostering further developments. The Python tools provide a simple syntax, Object Oriented Programming techniques, powerful mathematical and numerical tools, and a userfriendly environment.
Download or read book Root Water Uptake Model Depending on Soil Water Pressure Head and Maximum Extraction Rate written by J. C. Hoogland and published by . This book was released on 1981 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Solution of Partial Differential Equations written by K. W. Morton and published by Cambridge University Press. This book was released on 2005-04-11 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the 2005 second edition of a highly successful and well-respected textbook on the numerical techniques used to solve partial differential equations arising from mathematical models in science, engineering and other fields. The authors maintain an emphasis on finite difference methods for simple but representative examples of parabolic, hyperbolic and elliptic equations from the first edition. However this is augmented by new sections on finite volume methods, modified equation analysis, symplectic integration schemes, convection-diffusion problems, multigrid, and conjugate gradient methods; and several sections, including that on the energy method of analysis, have been extensively rewritten to reflect modern developments. Already an excellent choice for students and teachers in mathematics, engineering and computer science departments, the revised text includes more latest theoretical and industrial developments.
Download or read book Soil Water Interactions written by Iwata and published by CRC Press. This book was released on 2020-08-26 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emphasizing pioneering achievements, this work offers a clear and systematic description of various soil-water phenomena and their applications to soil problems such as water retention and the flux of water in soils and clays. This second edition contains material on the physical properties of adsorbed water, the application of fractal theory to solute and water flows in field soils, fingering research, and more.
Download or read book The Root Systems in Sustainable Agricultural Intensification written by Zed Rengel and published by John Wiley & Sons. This book was released on 2021-04-19 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explore an in-depth and insightful collection of resources discussing various aspects of root structure and function in intensive agricultural systems The Root Systems in Sustainable Agricultural Intensification delivers a comprehensive treatment of state-of-the-art concepts in the theoretical and practical aspects of agricultural management to enhance root system architecture and function. The book emphasizes the agricultural measures that enhance root capacity to develop and function under a range of water and nutrient regimes to maximize food, feed, and fibre production, as well as minimize undesirable water and nutrient losses to the environment. This reference includes resources that discuss a variety of soil, plant, agronomy, farming system, breeding, molecular and modelling aspects to the subject. It also discusses strategies and mechanisms that underpin increased water- and nutrient-use efficiency and combines consideration of natural and agricultural systems to show the continuity of traits and mechanisms. Finally, the book explores issues related to the global economy as well as widespread social issues that arise from, or are underpinned by, agricultural intensification. Readers will also benefit from the inclusion of: A thorough introduction to sustainable intensification, including its meaning, the need for the technology, components, and the role of root systems Exploration of the dynamics of root systems in crop and pasture genotypes over the last 100 years Discussion of the interplay between root structure and function with soil microbiome in enhancing efficiency of nitrogen and phosphorus acquisition Evaluation of water uptake in drying soil, including balancing supply and demand Perfect for agronomists, horticulturalists, plant and soil scientists, breeders, and soil microbiologists, The Root Systems in Sustainable Agricultural Intensification will also earn a place in the libraries of advanced undergraduate and postgraduate students in this field who seek a one-stop reference in the area of root structure and function.
Download or read book Advanced Tomographic Methods in Materials Research and Engineering written by John Banhart and published by Oxford University Press. This book was released on 2008-03-20 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tomography provides 3D images of materials or engineering components and an unprecedented insight into their internal structure. This book discusses developments in the field, such as the extension of tomographic methods to materials research and engineering.
Download or read book Plant Aquaporins written by François Chaumont and published by Springer. This book was released on 2017-02-07 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aquaporins are channel proteins that facilitate the diffusion of water and small uncharged solutes across cellular membranes. Plant aquaporins form a large family of highly divergent proteins that are involved in many different physiological processes. This book will summarize the recent advances regarding plant aquaporins, their phylogeny, structure, substrate specificity, mechanisms of regulation and roles in various important physiological processes related to the control of water flow and small solute distribution at the cell, tissue and plant level in an ever-changing environment.
Download or read book Water Flow and Solute Transport in Soils written by David Russo and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: A year has passed since Eshel Bresler, my good friend and colleague, and a member of the editorial board of the Advanced Series in Agricultural Sciences, died suddenly while on a visit to the Chinese Academy of Sciences in Beijing. We had worked together for almost 30 years at the Institute of Soils and Water, ARO, The Volcani Center at Bet Dagan. At the very beginning of our scientific careers we cooperated directly and as a result one of our first publications was coauthored (Soil Sci. 101:205-209, 1966). Thereafter, our specific research interests diver sified, but we continued to work together, with similar approaches to research, and to strive towards the development of Israel soil science and its integration into general worldwide scientific progress. I don't need to emphasize Eshel's contribution to the understan ding of the processes governing water flow and solute transport pro cesses in soils and unsaturated zones. The contributions to this Volume by such a body of outstanding scientists shows the apprecia tion of the international scientific community to his research achievements.
Download or read book Evolutionary Algorithms in Theory and Practice written by Thomas Back and published by Oxford University Press. This book was released on 1996-01-11 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a unified view of evolutionary algorithms: the exciting new probabilistic search tools inspired by biological models that have immense potential as practical problem-solvers in a wide variety of settings, academic, commercial, and industrial. In this work, the author compares the three most prominent representatives of evolutionary algorithms: genetic algorithms, evolution strategies, and evolutionary programming. The algorithms are presented within a unified framework, thereby clarifying the similarities and differences of these methods. The author also presents new results regarding the role of mutation and selection in genetic algorithms, showing how mutation seems to be much more important for the performance of genetic algorithms than usually assumed. The interaction of selection and mutation, and the impact of the binary code are further topics of interest. Some of the theoretical results are also confirmed by performing an experiment in meta-evolution on a parallel computer. The meta-algorithm used in this experiment combines components from evolution strategies and genetic algorithms to yield a hybrid capable of handling mixed integer optimization problems. As a detailed description of the algorithms, with practical guidelines for usage and implementation, this work will interest a wide range of researchers in computer science and engineering disciplines, as well as graduate students in these fields.
