نتایج جستجو برای: extent of irrigated lands

تعداد نتایج: 21166871  

Journal: :E3S web of conferences 2021

The article describes the construction technology of closed horizontal drainage in irrigated areas, presents results theoretical studies to determine depth drainage, width trench, diameter pipe, thickness filter material, distance between drains and module. According studies, average is 1.5 m , trench 0.3 pipe 0.1 filtration material . 150 with module l/s 180 a drain 0.12 210 0.14

Journal: :تحقیقات اقتصاد و توسعه کشاورزی ایران 0
فاطمه رزاقی بورخانی دانشجوی کارشناسی ارشد ، پردیس کشاورزی و منابع طبیعی دانشگاه تهران علی اسدی دانشیار پردیس کشاورزی و منابع طبیعی دانشگاه تهران

the main purpose of this research was to investigate farmer’s attitude towards privatization of agricultural extension in shirgah district , mazandaran province. the statistical population consisted of 15300 farmers who inhabited as residents in 54 villages. using stratified proportional random sampling, 150 farmers (through cochran formula) were selected. the study revealed that 84% of farmers...

2018
Beverly E Law Tara W Hudiburg Logan T Berner Jeffrey J Kent Polly C Buotte Mark E Harmon

Strategies to mitigate carbon dioxide emissions through forestry activities have been proposed, but ecosystem process-based integration of climate change, enhanced CO2, disturbance from fire, and management actions at regional scales are extremely limited. Here, we examine the relative merits of afforestation, reforestation, management changes, and harvest residue bioenergy use in the Pacific N...

2002
S. A. O. Chamshama J. B. Nduwayezu

Tanzania 2002 Summary The continued vicious cycle of population-poverty-and-environmental degradation has been acknowledged. The purpose of this paper, therefore, is to draw attention to the serious consequences of land degradation, a national and trans-national socioeconomic complex problem, and the need for rehabilitating degraded lands in the sub-humid lands of Sub-Saharan Africa (SSA). The ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده زیست شناسی 1388

126 abstract: in this research we studied the effects of cyclic hydration and dehydration of cysts of artemia urmiana and artemia parthenogenetica on the hatching percentage, survival and growth. the experiment was carried out in 3 treatments (1-3 hydration/dehydration cycles) with 3 replicates for each treatment. later effects of cold preservation at -20°c during three time periods were ...

2008
Reiner Wassmann Christopher Martius Wulf Amelung Charles Rodgers Nick van de Giesen

Land-use and agricultural practices affect the soil microbial carbon (C) and nitrogen (N) turnover and hence the biosphere-atmosphere exchange of greenhouse gasses (GHG), namely N2O, CH4 and CO2. In view of the global importance of irrigated agriculture, it is crucial to understand how and to which extent this land-use system interferes with the terrestrial N and C cycles and contributes to the...

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