Simulation of Field Water Use and Crop Yield PDF Download

Author: R. A. Feddes
Publisher: Halsted Press
ISBN: 9780470264638
Category : Crop yields
Languages : en
Pages : 188

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Book Description
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.

Author: J. Goudriaan
Publisher: Springer Science & Business Media
ISBN: 9401107505
Category : Science
Languages : en
Pages : 247

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Book Description
We dedicate this book to professor C. T. de Wit (1924 - 1993) who initiated Production Ecology as a school of thought at the Wageningen Agricultural Univer sity (see Rabbinge et at. , 1990). To acknowledge the leading role of C. T. de Wit, a recently formed graduate school at this university in Production Ecology was named after him. Production Ecology is the study of ecological processes, with special attention to flows of energy and matter as factors that determine the productivity of ecological systems. Agro-ecosystems are a special case of ecosystems which are much better suited for the productivity approach than natural ecosystems are. This is the reason for the strong role of agricultural research in production ecology. On the other hand, it must be recognized that the spatial heterogeneity of natural ecosys tems and their species richness may alter some ecophysiological relationships. However, the basic physical, chemical and physiological processes will be the same. De Wit introduced the state variable approach as the basis for simulation mod elling. In this approach the floating character of nature is schematized into a series of snapshots over time in which the states are frozen at each separate moment. The current state determines how the rates of change will lead to the next snapshot. This way of thinking enables a clear and workable representation of interacting simul taneous processes, without compromising on the mathematics.

Author: Martin J. Kropff
Publisher: Int. Rice Res. Inst.
ISBN: 0851987451
Category : Science
Languages : en
Pages : 277

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Book Description
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.

Author: Lajpat Ahuja
Publisher: Water Resources Publication
ISBN: 9781887201087
Category : Technology & Engineering
Languages : en
Pages : 388

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Book Description
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.

Author: Marco Bittelli
Publisher:
ISBN: 0199683093
Category : Science
Languages : en
Pages : 461

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Book Description
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.

Author: Gordon Bonan
Publisher: Cambridge University Press
ISBN: 1107043786
Category : Mathematics
Languages : en
Pages : 459

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Book Description
Provides an essential introduction to modeling terrestrial ecosystems in Earth system models for graduate students and researchers.

Author: François Chaumont
Publisher: Springer
ISBN: 3319493957
Category : Science
Languages : en
Pages : 354

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Book Description
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.

Author: Thomas Back
Publisher: Oxford University Press
ISBN: 0195356705
Category : Computers
Languages : en
Pages : 329

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Book Description
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.

Author: Jun J. Abe
Publisher: Springer Science & Business Media
ISBN: 9401729239
Category : Science
Languages : en
Pages : 444

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Book Description
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.

Author: Zoe G. Cardon
Publisher: Elsevier
ISBN: 0080493041
Category : Technology & Engineering
Languages : en
Pages : 235

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Book Description
Below the soil surface, the rhizosphere is the dynamic interface among plant roots, soil microbes and fauna, and the soil itself, where biological as well as physico-chemical properties differ radically from those of bulk soil. The Rhizosphere is the first ecologically-focused book that explicitly establishes the links from extraordinarily small-scale processes in the rhizosphere to larger-scale belowground patterns and processes. This book includes chapters that emphasize the effects of rhizosphere biology on long-term soil development, agro-ecosystem management and responses of ecosystems to global change. Overall, the volume seeks to spur development of cross-scale links for understanding belowground function in varied natural and managed ecosystems. - First cross-scale ecologically-focused integration of information at the frontier of root, microbial, and soil faunal biology - Establishes the links from extraordinarily small-scale processes in the rhizosphere to larger-scale belowground patterns and processes - Includes valuable information on ecosystem response to increased atmospheric carbon dioxide and enhanced global nitrogen deposition - Chapters written by a variety of experts, including soil scientists, microbial and soil faunal ecologists, and plant biologists