نتایج جستجو برای: crop loss assessment

تعداد نتایج: 1050376  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده فنی و مهندسی 1391

در این پروژه فیلترهای مایکرواستریپ جدیدی برای به‎‎دست آوردن اندازه‎ی فشرده، پاسخ تیز و نیز باند قطع عریض ارائه‎ شده است که از جمله‎ی آن ها فیلتری است که از سری شدن یک رزوناتور شاخه‎ای منتهی به نیم‎دایره و یک تکه‎ی‎ شعاعی بهبود یافته به عنوان تضعیف کننده‎ی هارمونیک، تشکیل شده است. فرکانس قطع -3 db این فیلتر در 1.54 ghz قرار دارد. باند‎ گذر این فیلتر تنها 0.26 ghz است که شامل محدوده‎ی فرکانسی 1.5...

2005
C. Tonitto M. B. David L. E. Drinkwater

The availability of Haber-Bosch nitrogen (N) has permitted agricultural intensification and increased the productive capacity of agroecosystems; however, approximately 50% of this applied fertilizer N is lost from agricultural landscapes. Extensive efforts have been devoted to improving the N use efficiency of these systems. Diversified crop rotations using cover crops to provide a variety of e...

2010
Dilip R. Panthee Feng Chen

Tomato (Solanum lycopersicum) is an important vegetable crop worldwide. Often times, its production is hindered by fungal diseases. Important fungal diseases limiting tomato production are late blight, caused by Phytophthora infestans, early blight, caused by Alternaria solanii, and septoria leaf spot, caused by Septoria lycopersici, fusarium wilt caused by Fusarium oxysporium fsp. oxysporium, ...

2014
Amanda D. Webber Catherine M. Hill

Considering how people perceive risks to their livelihoods from local wildlife is central to (i) understanding the impact of crop damage by animals on local people and (ii) recognising how this influences their interactions with, and attitudes towards, wildlife. Participatory risk mapping (PRM) is a simple, analytical tool that can be used to identify and classify risk within communities. Here ...

Journal: :Journal of environmental quality 2004
J S Strock P M Porter M P Russelle

Despite the use of best management practices for nitrogen (N) application rate and timing, significant losses of nitrate nitrogen (NO3(-)-N) in drainage discharge continue to occur from row crop cropping systems. Our objective was to determine whether a autumn-seeded winter rye (Secale cereale L.) cover crop following corn (Zea mays L.) would reduce NO3(-)-N losses through subsurface tile drain...

2011
Sijie Wu Jianxi Huang Xingquan Liu Jinlong Fan Guannan Ma Jinqiu Zou

Regional crop yield prediction is a vital component of national food security assessment. Data assimilation method which combines crop growth model and remotely sensed data has been proven the most potential method in regional crop production estimation. This paper takes Hengshui district as study area, WOFOST as crop model, MODIS-LAI as observation data to test and verify the efficiency of EnK...

Journal: :محیط شناسی 0
اطهره نژادی مجید مخدوم سید مسعود منوری علی بالی حمید فراهانی راد

human activities often adversely affect natural landscapes and ecosystems. natural landscapes consist of habitats, and habitat loss and fragmentation are major threats to biodiversity. environmental impact assessment (eia)as a systematic and well documented procedure to identify, describe and assess the direct and indirect effects of a developmental project in different environments does not co...

2013
Grazia Zulian Joachim Maes Maria Luisa Paracchini

Pollination is a key ecosystem service as many crops but in particular, fruits and vegetables are partially dependent on pollinating insects to produce food for human consumption. Here we assessed how pollination services are delivered at the European scale. We used this assessment to estimate the relative contribution of wild pollinators to crop production. We developed an index of relative po...

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