نتایج جستجو برای: agricultural water productivity

تعداد نتایج: 706292  

2017
Saeid Ashraf Vaghefi Karim C. Abbaspour Monireh Faramarzi Raghavan Srinivasan Jeffrey G. Arnold Athanasios Loukas

This study examines the water productivity of irrigated wheat and maize yields in Karkheh River Basin (KRB) in the semi-arid region of Iran using a coupled modeling approach consisting of the hydrological model (SWAT) and the river basin water allocation model (MODSIM). Dynamic irrigation requirements instead of constant time series of demand were considered. As the cereal production of KRB pla...

Journal: Money and Economy 2016

Understanding the dynamics of productivity shocks is instrumental if we are to identify the sources of economic growth. This paper, investigates dynamic effects of positives productivity shocks to agricultural subsectors during the period from 1991-2015, by disaggregating agricultural sector in Iran into four key subsectors (crops, livestock, fishing and forestry) through an estimated DSGE mode...

Journal: :international journal of environmental research 2013
s. rasi nezami m. nazariha a. moridi a. baghvand

maharlou-bakhtegan catchment in the southern part of iran is faced with water scarcity.this problem is exacerbated by environmental degradation, climate change effects, mismanagementof water resources, along with a major dependence of water demand supplies on the limitedgroundwater resources. in this study, a combined approach of dpsir model along with the scenarioanalysis was employed to deriv...

2015
Insa Flachsbarth Bárbara Willaarts Hua Xie Gauthier Pitois Nathaniel D. Mueller Claudia Ringler Alberto Garrido

One of humanity's major challenges of the 21st century will be meeting future food demands on an increasingly resource constrained-planet. Global food production will have to rise by 70 percent between 2000 and 2050 to meet effective demand which poses major challenges to food production systems. Doing so without compromising environmental integrity is an even greater challenge. This study look...

Energy carriers are one of the most important inputs in the agricultural sector. These inputs have been the foundation of the development and transition of the agricultural sector from the traditional stage to the industrial stage. The energy per capita marginal consumption in Iran’s agricultural sector is 3.2 times greater than its global average. Therefore, it is essential to save and optimal...

Journal: :iran agricultural research 2016
s. negarchi m.r. zare mehrjerdi h. mehrabi boshrabadi h. nezamabadi pour

abstract-due to the important role productivity plays in future decision making and programming, the productivity indexes should have accurate quantities. in this study, auto-regressive distributed lag (ardl) and genetic algorithm (ga) methods are applied to time series of 1978-2008 to accurately measure total factor productivity (tfp) in the agricultural sector of iran. the comparison of these...

2011
Emile A. Frison

Agricultural biodiversity has hitherto been valued almost exclusively as a source of traits that can be used in scientific breeding programs to improve the productivity of crop varieties and livestock breeds. We argue that it can make a far greater contribution to increased productivity. In particular, a wider deployment of agricultural biodiversity is an essential component in the sustainable ...

Journal: :زراعت دیم ایران 0
علیرضا توکلی مرکز تحقیقات کشاورزی و منابع طبیعی استان سمنان (شاهرود)

to study the effect of sowing date and a single irrigation (si) on yield and yield components of barley, a field experiment was conducted in dryland agricultural research institute (maragheh, iran) in 2004-06 cropping seasons, using a split plot based on a randomized complete block design with 3 replications. main plots were assigned to 3 levels of sowing date (early, normal and late). sub-plot...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2017
Xin-Zhong Liang You Wu Robert G Chambers Daniel L Schmoldt Wei Gao Chaoshun Liu Yan-An Liu Chao Sun Jennifer A Kennedy

The sensitivity of agricultural productivity to climate has not been sufficiently quantified. The total factor productivity (TFP) of the US agricultural economy has grown continuously for over half a century, with most of the growth typically attributed to technical change. Many studies have examined the effects of local climate on partial productivity measures such as crop yields and economic ...

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