Yield gap analysis of field crops
Yield gap analysis of field crops

Author: Food and Agriculture Organization of the United Nations

Publisher: Food & Agriculture Org.

Published: 2018-06-29

Total Pages: 82

ISBN-13: 9251088136

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To feed a world population that will exceed 9 billion by 2050 requires an estimated 60% increase over current primary agricultural productivity. Closing the common and often large gap between actual and attainable crop yield is critical to achieve this goal. To close yield gaps in both small and large scale cropping systems worldwide we need (1) definitions and techniques to measure and model yield at different levels (actual, attainable, potential) and different scales in space (field, farm, region, global) and time (short and long term); (2) identification of the causes of gaps between yield levels; (3) management options to reduce the gaps where feasible and (4) policies to favour adoption of sustainable gap-closing solutions. The aim of this publication is to critically review the methods for yield gap analysis, hence addressing primarily the first of these four requirements, reporting a wide-ranging and well-referenced analysis of literature on current methods to assess productivity of crops and cropping systems.

Evaporation, Evapotranspiration, and Irrigation Water Requirements
Evaporation, Evapotranspiration, and Irrigation Water Requirements

Author: American Society of Civil Engineers. Task Committee on Revision of Manual 70

Publisher: ASCE Press

Published: 2016

Total Pages: 0

ISBN-13: 9780784414057

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MOP 70 is a comprehensive reference to estimating the water quantities needed for irrigation of crops projects based upon the physics of evaporation and evapotranspiration (ET).

Satellite Remote Sensing for Assessment of Irrigation System Performance
Satellite Remote Sensing for Assessment of Irrigation System Performance

Author: S. Thiruvengadachari

Publisher: IWMI

Published: 1997

Total Pages: 31

ISBN-13: 9290903376

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Describes the use of satellite remote sensing and geographic information system techniques to obtain information on primary agricultural productivity and irrigation system performance in a large rice irrigation system in India. Discusses the potential and cost-effectiveness of SRS techniques for making inventories and monitoring agricultural productivity.

Water Productivity in Agriculture
Water Productivity in Agriculture

Author: J. W. Kijne

Publisher: CABI

Published: 2003

Total Pages: 354

ISBN-13: 1845933397

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First title in a major new seriesAddresses improving water productivity to relieve problems of scarcity and competition to provide for food and environmental securityDraws from scientists having a multitude of disciplines to approach this important problemIn a large number of developing countries, policy makers and researchers are increasingly aware of the conflicting demands on water, and look at agriculture to be more effective in its use of water. Focusing on both irrigated and rain-fed agriculture, this book gives a state of the art review of the limits and opportunities for improving water productivity in crop production. It demonstrates how efficiency of water use can be enhanced to maximize yields. The book represents the first in a new series of volumes resulting from the Comprehensive Assessment of Water Management in Agriculture, a research program conducted by the CGIAR's Future Harvest Centres, the Food and Agriculture Organization of the United Nations and partners worldwide. It will be of significant interest to those working in areas of soil and crop science, water management, irrigation, and development studies.

Advanced Evapotranspiration Methods and Applications
Advanced Evapotranspiration Methods and Applications

Author: Daniel Bucur

Publisher: BoD – Books on Demand

Published: 2019-04-03

Total Pages: 142

ISBN-13: 1789858119

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Since the beginning of its formation approximately three billion years ago, the hydrosphere - as an envelope of the terrestrial ellipsoid - has remained constant from a quantitative point of view. The hydrosphere modifies only the ratio of the stretches of the planetary ocean and land, including the proportion of the states of water aggregation: gaseous, liquid, and solid.The hydrological cycle transports only a portion of the hydrosphere, repeats itself annually, and presents itself as a huge planetary plant that for billions of years has operated uninterruptedly on the basis of solar energy and gravity, providing freshwater resources for the maintenance and perpetuation of life beyond the planetary ocean.Water resources are highly influenced by the hydrologic cycle and play a role in agricultural economic development. However, as is shown by the Intergovernmental Panel on Climate Change report, the phenomena of changing climate and land use are set to exacerbate an already serious situation of water supply for various users. In this context, scientific investigations into the issue of the sustainable use of water are timely and important. Improvement of water management involves the accurate estimation of consumptive uses. The purpose of this book is to show the achievements of scientists and academicians all over the world in promoting and sharing new issues on various topics related to evapotranspiration.

Agroclimatology
Agroclimatology

Author: Jerry L. Hatfield

Publisher: John Wiley & Sons

Published: 2020-01-22

Total Pages: 656

ISBN-13: 0891183574

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Can we unlock resilience to climate stress by better understanding linkages between the environment and biological systems? Agroclimatology allows us to explore how different processes determine plant response to climate and how climate drives the distribution of crops and their productivity. Editors Jerry L. Hatfield, Mannava V.K. Sivakumar, and John H. Prueger have taken a comprehensive view of agroclimatology to assist and challenge researchers in this important area of study. Major themes include: principles of energy exchange and climatology, understanding climate change and agriculture, linkages of specific biological systems to climatology, the context of pests and diseases, methods of agroclimatology, and the application of agroclimatic principles to problem-solving in agriculture.

Remote Sensing of Evapotranspiration (ET)
Remote Sensing of Evapotranspiration (ET)

Author: Pradeep Wagle

Publisher: MDPI

Published: 2019-10-11

Total Pages: 240

ISBN-13: 3039216023

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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.

Estimation of Evapotranspiration Rates in Irrigated Lands of the Fergana Valley using Stable Isotopes
Estimation of Evapotranspiration Rates in Irrigated Lands of the Fergana Valley using Stable Isotopes

Author: Gulomjon Umirzakov

Publisher: Cuvillier Verlag

Published: 2016-03-30

Total Pages: 144

ISBN-13: 3736982240

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Agriculture in Uzbekistan critically depends on water resources availability, therefore crop production, especially of cotton and winter wheat, is restricted mainly to irrigated areas. As a result of water shortage under climate change, land degradation issues in the region worsened and water use efficiency has considerably decreased over the decades. Hence, it is essential to investigate water balance parameters in irrigated lands. Environmental isotopes have been widely applied in hydrological investigations, particularly estimation of evapotranspiration rate, one of the main components of the water balance in irrigated lands. This study aims to estimate evapotranspiration rates in cotton fields by applying water stable isotopes (2H and 18O). The study is based on the field experiments conducted during the vegetation periods 2010 and 2011 in the Fergana Region of Uzbekistan. Soil for isotope analysis were sampled in a sandy field, sandy loam #1 field (rich with gypsum) and sandy loam #2 field (without gypsum). The soil water from the samples was extracted by the cryogenic extraction method. δ2H and δ18O ratios of extracted water were determined using the laser spectroscopy method. Evapotranspiration rates were estimated with the isotope mass balance model. Besides evapotranspiration estimation, this study examines the variability and characteristics of stable isotope signatures of different water sources in the study region and analyzes water extraction processes from different soil types and temporal changes of isotope signatures through the depth in irrigated cotton fields.

Guidance on realizing real water savings with crop water productivity interventions
Guidance on realizing real water savings with crop water productivity interventions

Author: Van Opstal, J., Droogers, P., Kaune, A., Steduto, P., Perry, C.

Publisher: Food & Agriculture Org.

Published: 2021-03-18

Total Pages: 63

ISBN-13: 9251341362

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This technical document contains clear and practical guidelines on how to implement real water savings in agriculture through interventions for enhancing crop water productivity. A distinction is made between real water savings and “apparent” water savings. Apparent water savings record reductions in water withdrawals but do not account for changes in water consumption. Real water savings record reductions in water consumption and non-recoverable return flows (runoff or percolation). This guidance document emphasizes the paradox of water savings at field and basin scales, which usually do not translate into increased water availability for other users, as is commonly believed.