Evapotranspiration In The Soil Plant Atmosphere System

Evapotranspiration and its components (evaporation and transpiration) as a process is one of the basic terms of Earth's water balance; its importance is accented by the fact that transpiration is the vital element of the biomass production process. The second important property of evapotranspiration is its extreme consumption of solar energy, thus controlling the temperature of the atmosphere and creating favourable conditions for life. Evapotranspiration as an energy consuming process is also the connection between the energy and mass cycles of the Earth. Evapotranspiration is a process performing in the Soil–Plant –Atmosphere System (SPAS); therefore this book is presenting and quantifying it as a catenary process, describing transport of water in the soil, including root extraction patterns and methods of its evaluation. Transport of water through the plant and from the canopy to the atmosphere is also described and quantified. A variety of evapotranspiration (and its components evaporation and transpiration) calculation methods are described, starting from empirical methods up to the most sophisticated ones based on the solution of the transport equations of water and energy in the SPAS. The most important (and widely used) calculation method - modified Penman–Monteith method is described in details, ready to be used with data in the book only. Water balance method of evapotranspiration estimation as well as sap flow method description can be found in the book as well. The book can be used by hydrologists, biologists, meteorologists and other specialists as well as by ecology students. Key themes: soil hydrology – evapotranspiration – hydropedology– plant physiology – water movement in soils – evaporation – transpiration Dr. Viliam Novák is a water resources scientist at the Institute of Hydrology of the Slovak Academy of Sciences in Bratislava (Slovakia).

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 and physics, are well explained, even to readers not well acquainted with these tools. Therefore, it helps students read, understand, and developing their thoughts on these subjects. Instructors also find it an easy book with the needed depth to be adopted in courses related to Soil Physics, Agricultural Management, Environmental Protection, Irrigation and Agrometeorology. It serves also as “lexicon” to engineers and lawyers involved in agricultural, environmental cases.

Fluxes of trace gases, water and energy - the 'breathing of the biosphere' - are controlled by a large number of interacting physical, chemical, biological and ecological processes. In this interdisciplinary book, the authors provide the tools to understand and quantitatively analyse fluxes of energy, organic compounds such as terpenes, and trace gases including carbon dioxide, water vapour and methane. It first introduces the fundamental principles affecting the supply and demand for trace gas exchange at the leaf and soil scales: thermodynamics, diffusion, turbulence and physiology. It then builds on these principles to model the exchange of water, carbon dioxide, terpenes and stable isotopes at the ecosystem scale. Detailed mathematical derivations of commonly used relations in biosphere-atmosphere interactions are provided for reference in appendices. An accessible introduction for graduate students and a key resource for researchers in related fields, such as atmospheric science, hydrology, meteorology, climate science, biogeochemistry and ecosystem ecology.

This Encyclopedia of Agrophysics will provide up-to-date information on the physical properties and processes affecting the quality of the environment and plant production. It will be a "first-up" volume which will nicely complement the recently published Encyclopedia of Soil Science, (November 2007) which was published in the same series. In a single authoritative volume a collection of about 250 informative articles and ca 400 glossary terms covering all aspects of agrophysics will be presented. The authors will be renowned specialists in various aspects in agrophysics from a wide variety of countries. Agrophysics is important both for research and practical use not only in agriculture, but also in areas like environmental science, land reclamation, food processing etc. Agrophysics is a relatively new interdisciplinary field closely related to Agrochemistry, Agrobiology, Agroclimatology and Agroecology. Nowadays it has been fully accepted as an agricultural and environmental discipline. As such this Encyclopedia volume will be an indispensable working tool for scientists and practitioners from different disciplines, like agriculture, soil science, geosciences, environmental science, geography, and engineering.

The focus of this work is the development of models to estimate evapotranspiration (ET), investigating the partitioning between soil evaporation and plant transpiration at field and regional scales, and calculating ET over heterogeneous vegetated surfaces. Different algorithms with varying complexities as well as spatial and temporal resolutions are developed to estimate evapotranspiration from different data inputs. The author proposes a novel approach to estimate ET from remote sensing by exploiting the linkage between water and carbon cycles. At the field scale, a hybrid dual source model (H-D model) is proposed. It is verified with field observations over four different ecosystems and coupled with a soil water and heat transfer model, to simulate water and heat transfer in the soil-plant-atmosphere continuum. At the regional scale, a hybrid dual source scheme and trapezoid framework based ET model (HTEM), using remote sensing images is developed. This model is verified with data from the USA and China and the impact of agricultural water-saving on ET of different land use types is analyzed, in these chapters. The author discusses the potential of using a remote sensing ET model in the real management of water resources in a large irrigation district. This work would be of particular interest to any hydrologist or micro-meteorologist who works on ET estimation and it will also appeal to the ecologist who works on the coupled water and carbon cycles. Land evapotranspiration is an important research topic in hydrology, meteorology, ecology and agricultural sciences. Dr. Yuting Yang works at the CSIRO Land and Water, Canberra, Australia.

Principles of Soil and Plant Water Relations, 2e describes the principles of water relations within soils, followed by the uptake of water and its subsequent movement throughout and from the plant body. This is presented as a progressive series of physical and biological interrelations, even though each topic is treated in detail on its own. The book also describes equipment used to measure water in the soil-plant-atmosphere system. At the end of each chapter is a biography of a scientist whose principles are discussed in the chapter. In addition to new information on the concept of celestial time, this new edition also includes new chapters on methods to determine sap flow in plants dual-probe heat-pulse technique to monitor water in the root zone. Provides the necessary understanding to address advancing problems in water availability for meeting ecological requirements at local, regional and global scales Covers plant anatomy: an essential component to understanding soil and plant water relations

The first premise of this book is that farmers need access to options for improving their situation. In agricultural terms, these options might be manage ment alternatives or different crops to grow, that can stabilize or increase household income, that reduce soil degradation and dependence on off-farm inputs, or that exploit local market opportunities. Farmers need a facilitating environment, in which affordable credit is available if needed, in which policies are conducive to judicious management of natural resources, and in which costs and prices of production are stable. Another key ingredient of this facilitating environment is information: an understanding of which options are viable, how these operate at the farm level, and what their impact may be on the things that farmers perceive as being important. The second premise is that systems analysis and simulation have an impor tant role to play in fostering this understanding of options, traditional field experimentation being time-consuming and costly. This book summarizes the activities of the International Benchmark Sites Network for Agrotechnology Transfer (IBSNAT) project, an international initiative funded by the United States Agency for International Development (USAID). IBSNAT was an attempt to demonstrate the effectiveness of understanding options through systems analysis and simulation for the ultimate benefit of farm households in the tropics and subtropics. The idea for the book was first suggested at one of the last IBSNAT group meetings held at the University of Hawaii in 1993.

The following advances in technology for measurement of water potential are described: (1) A thermocouple for direct attachment to plant leaves; (2) A microchamber for studying plant responses to environment is described. Light intensity and duration, ambient temperature, relative humidity, and CO2 concentration are controlled. Transpiration, CO2 assimilation, and plant and soil water potential are measured. Data for the ratio of transpiration to CO2 assimilation for cotton are given. Moderate salinity increased this ratio. Description of a contact closure distributor to make a data acquisition system serve as a control device as well as a recorder is given. Also described is a tape editor for handling output data from the system. Preliminary results from experiments to determine how plants integrate time varying salinity indicate that transpiration per unit leaf area is decreased by salinity. (Author).

Evapotranspiration (ET) is a critical component of the water and energy balances, and the number of remote sensing-based ET products and estimation methods has increased in recent years. Various aspects of remote sensing of ET are reported in the 11 papers published in this book. The major research areas covered by this book include inter-comparison and performance evaluation of widely used one- and two-source energy balance models, a new dual-source model (Soil Plant Atmosphere and Remote Sensing Evapotranspiration, SPARSE), and a process-based model (ETMonitor); assessment of multi-source (e.g., remote sensing, reanalysis, and land surface model) ET products; development or improvement of data fusion frameworks to predict continuous daily ET at a high spatial resolution (field-scale or 30 m) by fusing the advanced spaceborne thermal emission reflectance radiometer (ASTER), the moderate resolution imaging spectroradiometer (MODIS), and Landsat data; and investigating uncertainties in ET estimates using an ET ensemble composed of several land surface models and diagnostic datasets. The effects of the differences between ET products on water resources and ecosystem management were also investigated. More accurate ET estimates and improved understanding of remotely sensed ET products are crucial for maximizing crop productivity while minimizing water losses and management costs.