نتایج جستجو برای: water productivity

تعداد نتایج: 626905  

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2008
J I L Morison N R Baker P M Mullineaux W J Davies

Globally, agriculture accounts for 80-90% of all freshwater used by humans, and most of that is in crop production. In many areas, this water use is unsustainable; water supplies are also under pressure from other users and are being affected by climate change. Much effort is being made to reduce water use by crops and produce 'more crop per drop'. This paper examines water use by crops, taking...

Journal: :مدیریت خاک و تولید پایدار 0
حیدر غفاری دانشگاه تهران منوچهر گرجی دانشگاه تهران

maintaining soil productivity is one of the key factors in sustainable agriculture. soil erosion reduces soil productivity over a long-term period of time. therefore, determining soil erosion tolerance is necessary for sustainable agriculture production. in this study, the long-term effects of erosion on soil productivity in the typical kohin watershed were evaluated. the soil productivity inde...

Journal: :آب و توسعه پایدار 0
محمود خرمی وفا مهدی نوری فرزاد مندنی هادی ویسی

the study of virtual water and water productivity in agricultural crops requires the establishment of relations where represent the actual amount of water in order to produce the respective crop. this feature presents a new approach in studies regarding agricultural ecology. this survey evaluates the virtual water, water productivity and ecological water footprint of wheat and corn fields in th...

A.R. Sepaskhah, M. Noshadi S. Fahandej

In this research, the effects of irrigation with saline and fresh water through drip irrigation method and using two irrigation management strategies: M1, M2 (M1 is irrigation with fresh water in alternative with saline water, M2 is saline water in first half time of each irrigation event and fresh water in the second half), on the yield, water productivity (WP), soil salinity, plant height...

Journal: :The American naturalist 2013
Caroline E Farrior Ray Dybzinski Simon A Levin Stephen W Pacala

Abstract The dependence of forest productivity and community composition on rainfall is the result of complex interactions at multiple scales, from the physiology of carbon gain and water loss to competition among individuals and species. In an effort to understand the role of these multiscale interactions in the dependence of forest structure on rainfall, we build a tractable model of individu...

Journal: :Remote Sensing 2016
Gerardo Toro-Farmer Frank E. Müller-Karger Maria Vega-Rodriguez Nelson Melo Kimberly Yates Sergio Cerdeira-Estrada Stanley R. Herwitz

Light availability is an important factor driving primary productivity in benthic ecosystems, but in situ and remote sensing measurements of light quality are limited for coral reefs and seagrass beds. We evaluated the productivity responses of a patch reef and a seagrass site in the Lower Florida Keys to ambient light availability and spectral quality. In situ optical properties were character...

Journal: :JORS 2011
Maria Conceição A. Silva Portela Emmanuel Thanassoulis A. Horncastle T. Maugg

This paper uses a meta-Malmquist index for measuring productivity change of the water industry in England and Wales and compares this to the traditional Malmquist index. The meta-Malmquist index computes productivity change with reference to a meta-frontier, it is computationally simpler and it is circular. The analysis covers all 22 UK water companies in existence in 2007, using data over the ...

2009
A. K. Gilgen N. Buchmann

Water is an important resource for plant life. Since climate scenarios for Switzerland predict an average reduction of 20% in summer precipitation until 2070, understanding ecosystem responses to water shortage, e.g. in terms of plant productivity, is of major concern. Thus, we tested the effects of simulated summer drought on three managed grasslands along an altitudinal gradient in Switzerlan...

2013
Yuming Fang Steven J. Duranceau

To evaluate the significance of reverse osmosis (RO) and nanofiltration (NF) surface morphology on membrane performance, productivity experiments were conducted using flat-sheet membranes and three different nanoparticles, which included SiO2, TiO2 and CeO2. In this study, the productivity rate was markedly influenced by membrane surface morphology. Atomic force microscopy (AFM) analysis of mem...

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