نتایج جستجو برای: both weather simulations indicated similar annual crop yields nevertheless

تعداد نتایج: 2976080  

Journal: :Global change biology 2016
Zhenong Jin Qianlai Zhuang Zeli Tan Jeffrey S Dukes Bangyou Zheng Jerry M Melillo

Stresses from heat and drought are expected to increasingly suppress crop yields, but the degree to which current models can represent these effects is uncertain. Here we evaluate the algorithms that determine impacts of heat and drought stress on maize in 16 major maize models by incorporating these algorithms into a standard model, the Agricultural Production Systems sIMulator (APSIM), and ru...

2005
J. Lipiec V. V. Medvedev M. Birkas E. Dumitru

response to soil compaction associated with soil and crop type, and soil wetness at the time of load application and weather in Central and Eastern Europe are reviewed. The effects of soil compaction on the morphological and anatomical modifications of the roots were shown. The influence of soil compaction on plasticity in root growth and functioning in relation to structural discontinuity is d...

2005
Paul C. Doraiswamy Sophie Moulin Paul W. Cook Alan Stern

Monitoring crop condition and production estimates at the state and county level is of great interest to the U.S. Department of Agriculture. The National Agricultural Statistical Service (NASS) of the U.S. Department of Agriculture conducts field interviews with sampled farm operators and obtains crop cuttings to make crop yield estimates at regional and state levels. NASS needs supplemental sp...

Journal: :Journal of applied meteorology and climatology 2016
Michael J Glotter Elisabeth J Moyer Alex C Ruane Joshua W Elliott

Projections of future food production necessarily rely on models, which must themselves be validated through historical assessments comparing modeled to observed yields. Reliable historical validation requires both accurate agricultural models and accurate climate inputs. Problems with either may compromise the validation exercise. Previous studies have compared the effects of different climate...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده منابع طبیعی 1392

nowadays, air pollution is a global problem that has had significant growth by technology development, population growth andindustrial development. industrial development brought natural resources deterioration, more manufacturing products, and more environmental pollutants. if pollutant won’t be controlled, human-being and wildlife will face the critical risks. significant release and critical...

Journal: :international journal of agricultural science, research and technology in extension and education systems 2012
afshin morovvat mostafa emadi mosa shojae ahmad pakpour leila gholami

crop yields are dependent on a number of factors such as soil type, weather conditions and farming practices. crop yield estimates in different soil types are required to meet the needs of farmers, land appraisers, and governmental agencies in iran as around the world. this study was conducted to model the wheat-grain yields [triticum aestivum l.]  by soil properties in khoy area, the north-wes...

Journal: :International journal of biometeorology 2011
Mohammad Bannayan Sajad Sadeghi Lotfabadi Sarah Sanjani Azadeh Mohamadian Majid Aghaalikhani

Climate variability adversely impacts crop production and imposes a major constraint on farming planning, mostly under rainfed conditions, across the world. Considering the recent advances in climate science, many studies are trying to provide a reliable basis for climate, and subsequently agricultural production, forecasts. The El Niño-Southern Oscillation phenomenon (ENSO) is one of the princ...

2008
Lance T. Vermeire Rodney K. Heitschmidt Marshall R. Haferkamp

Grazing systems may alter botanical composition and productivity of grasslands through differential use in time, space, or intensity. Seven simulated grazing treatments were applied six years in eastern Montana, USA to determine effects on plant community composition and standing crop. Treatments were moderate stocking (28.8 AUD ha 1 year ) of cattle using 3-pasture summer rotation, season-long...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Paul C West Holly K Gibbs Chad Monfreda John Wagner Carol C Barford Stephen R Carpenter Jonathan A Foley

Expanding croplands to meet the needs of a growing population, changing diets, and biofuel production comes at the cost of reduced carbon stocks in natural vegetation and soils. Here, we present a spatially explicit global analysis of tradeoffs between carbon stocks and current crop yields. The difference among regions is striking. For example, for each unit of land cleared, the tropics lose ne...

2016
Betsie le Roux Michael van der Laan Teunis Vahrmeijer John G. Annandale Keith L. Bristow Arjen Y. Hoekstra Ashok K. Chapagain

Water footprint (WF) accounting as proposed by the Water Footprint Network (WFN) can potentially provide important information for water resource management, especially in water scarce countries relying on irrigation to help meet their food requirements. However, calculating accurate WFs of short-season vegetable crops such as carrots, cabbage, beetroot, broccoli and lettuce presented some chal...

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