نتایج جستجو برای: agricultural yields

تعداد نتایج: 194172  

2013
Juraj Balkovič Marijn van der Velde Erwin Schmid Rastislav Skalský Nikolay Khabarov Michael Obersteiner Bernhard Stürmer Wei Xiong

Justifiable usage of large-scale crop model simulations requires transparent, comprehensive and spatially extensive evaluations of their performance and associated accuracy. Simulated crop yields of a Pan-European implementation of the Environmental Policy Integrated Climate (EPIC) crop model were satisfactorily evaluated with reported regional yield data from EUROSTAT for four major crops, inc...

2014
Michael E. Hickey Gulnihal Ozbay

*Correspondence: Gulnihal Ozbay, The Department of Agriculture and Natural Resources, College of Agriculture and Related Sciences, Delaware State University, 1200 North DuPont Highway, Dover, DE, USA e-mail: [email protected] The world’s population continues to increase at record rates along with corresponding nutritional needs and related agricultural consequences. In the United States, food was...

2011
Marco Ferroni

Agriculture in Africa is not sustainable because average yields have been stagnating for decades due to underinvestment, especially in the development of agricultural markets, crop improvement and the sustainable management of agricultural systems. Low public sector funding for agricultural research and lack of incentives for the private sector to operate in areas where there is no market large...

A. Baghvand A. Karbassi Gh. Mohammadpour

In the recent years, agricultural soils have received more chemicals in various forms for higher yields. This may result in the accumulation of metals in soils which subsequently may be transferred into the agricultural crops. In the present investigation, nickel content of 58 composite soil samples and also agricultural crops, is studied. Ni in samples of soil and agricultural products were ex...

Journal: :Journal of environmental quality 2016
Mark B David Lowell E Gentry Corey A Mitchell

Sulfur received extensive study as an input to terrestrial ecosystems from acidic deposition during the 1980s. With declining S deposition inputs across the eastern United States, there have been many studies evaluating ecosystem response, with the exception of agricultural watersheds. We used long-term (22 and 18 yr) sulfate concentration data from two rivers and recent (6 yr) data from a thir...

2010
Anthony Fisher Michael Hanemann Michael J. Roberts Wolfram Schlenker

Despite the existence of a large and growing literature on the potential impact of climate change on agriculture, there still exists some disagreement about the magnitude and even the sign. Our own research suggests that the impact on U.S. agriculture is likely to be strongly negative, based on a series of studies in which we link farmland values to climate variables, and crop yields to both cl...

2016
Xiaoyun Li Nianjie Liu Liangzhi You Xinli Ke Haijun Liu Malan Huang Stephen R. Waddington

After a remarkable 86% increase in cereal production from 1980 to 2005, recent crop yield growth in China has been slow. County level crop production data between 1980 and 2010 from eastern and middle China were used to analyze spatial and temporal patterns of rice, wheat and maize yield in five major farming systems that include around 90% of China's cereal production. Site-specific yield tren...

Journal: :Science 2003
David B Lobell Gregory P Asner

“Climate and Management Contributions to Recent Trends in U.S. Agricultural Yields” Gu (1) claims that by analyzing a subset of counties, we guaranteed that temperature trends would significantly impact yields. This was not the case. If temperature trends were small, or if nonclimatic contributions to yields were large, then the effect of temperature trends on yields would have been insignifica...

Journal: :یافته های تحقیقاتی در گیاهان زراعی و باغی 0
خالد میری مرکز تحقیقات کشاورزی و منابع طبیعی بلوچستان، ایرانشهر

in order to study the effect of sowing methods and seeding rates on fodder yield and some agronomic characters of nikshahri alfalfa ecotype, an experiment was conducted in a split plot arrangement in randomized complete block design with four replications in the field of agricultural and natural resources center of baluchistan in iranshahr region. in this study, sowing methods: hand spread, 12 ...

Journal: :پژوهش های زراعی ایران 0
سعید صوفی زاده اسکندر زند رضا دیهیم فرد سعیده اسماعیل زاده

twentieth century had faced considerable increase in crops yields. nonetheless, it is postulated that world population will reach 10.4 billion until 2050 which means the demand for agricultural crops production should be increased between 60 and 110 percent. in the present study, improvements in grain yields of wheat, maize and rice during the recent decades in iran were studies through analyzi...

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