نتایج جستجو برای: a change in crop pattern

تعداد نتایج: 20437986  

Journal: :اقتصاد و توسعه کشاورزی 0
فهیمه بهرامی مهنه احمدعلی کیخا محمود صبوحی محمود احمدپور

introduction: water scarcity has become a global issue due to its direct relationship with food security. for this reason, the need for the long-term sustainable use of water necessitates the application of effective strategies. in this regard, strategic programs are utilized in water resource management and agricultural policies in order to increase self-sufficiency, to reduce the food gap, to...

Journal: :jundishapur journal of microbiology 0
abdolhassan kazemi tropical and infectious diseases research center, tabriz university of medical science, tabriz, ir iran, ir iran +98-4113373745, [email protected]; tropical and infectious diseases research center, tabriz university of medical science, tabriz, ir iran, ir iran +98-4113373745, [email protected]

Journal: :تحقیقات اقتصاد و توسعه کشاورزی ایران 0
سمانه عابدی غلامرضا پیکانی سید صفدر حسینی

comparative advantage of corn in comparison with other competing crops was investigated applying linear programming, to 2004-2005 data related to classic index (drc) in khuzestan. results showed that corn benefits from a comparative advantage in all cities of khuzestan province with acreage having been increased in the cultivation pattern of 37.5 % of the cities. in addition, comparing optimal ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - پژوهشکده ادبیات 1393

1.0 overview it seems that grammar plays a crucial role in the area of second and foreign language learning and widely has been acknowledged in grammar research. in other words, teaching grammar is an issue which has attracted much attention to itself, and a lot of teachers argue about the existence of grammar in language teaching and learning. this issue will remind us a famous sentence f...

امانی, فیروز, حاجی زاده, ابراهیم, حبیبی, رضا, کاظم نژاد, انوشیروان,

Background & Objectives: Changing the pattern of mortality gives important perspective of health determinants. The aim of this study is to detect location and time of mortality pattern change in country using statistical change point method during 1971-2009 Years. Methods: We assume for years before and after 0 k , t y has a Poisson distribution with means 0 l and 1 l , respectively. We ...

2018
Confidence Duku Sander J Zwart Lars Hein

In recent decades, there have been substantial increases in crop production in sub-Saharan Africa (SSA) as a result of higher yields, increased cropping intensity, expansion of irrigated cropping systems, and rainfed cropland expansion. Yet, to date much of the research focus of the impact of climate change on crop production in the coming decades has been on crop yield responses. In this study...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2004
Shaobing Peng Jianliang Huang John E Sheehy Rebecca C Laza Romeo M Visperas Xuhua Zhong Grace S Centeno Gurdev S Khush Kenneth G Cassman

The impact of projected global warming on crop yields has been evaluated by indirect methods using simulation models. Direct studies on the effects of observed climate change on crop growth and yield could provide more accurate information for assessing the impact of climate change on crop production. We analyzed weather data at the International Rice Research Institute Farm from 1979 to 2003 t...

2013
Junguo Liu Christian Folberth Hong Yang Johan Röckström Karim Abbaspour Alexander J. B. Zehnder

Food security and water scarcity have become two major concerns for future human's sustainable development, particularly in the context of climate change. Here we present a comprehensive assessment of climate change impacts on the production and water use of major cereal crops on a global scale with a spatial resolution of 30 arc-minutes for the 2030s (short term) and the 2090s (long term), res...

2014
Toshichika Iizumi Navin Ramankutty

Most studies of the influence of weather and climate on food production have examined the influence on crop yields. However, climate influences all components of crop production, includes cropping area (area planted or harvested) and cropping intensity (number of crops grown within a year). Although yield increases have predominantly contributed to increased crop production over the recent deca...

2017
Nicolas Guilpart Patricio Grassini Victor O. Sadras Jagadish Timsina Kenneth G. Cassman

Yield gap analyses of individual crops have been used to estimate opportunities for increasing crop production at local to global scales, thus providing information crucial to food security. However, increases in crop production can also be achieved by improving cropping system yield through modification of spatial and temporal arrangement of individual crops. In this paper we define the croppi...

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