نتایج جستجو برای: paddy fields

تعداد نتایج: 250627  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه گیلان - دانشکده کشاورزی 1391

مشارکت در مفهوم گسترده اش به معنی برانگیختن حساسیت مردم و نتیجتا به معنی افزایش درک و توان روستاییان جهت پاسخگویی به طرح های توسعه و نیز به مفهوم تشویق و ابتکارهای محلی است.مزارع شالی گیلان که بالغ بر 230000هکتار می باشد با بزرگترین مشکلات توسعه همراه است.قطعات کوچک و مرزبندی، نیود جاده مواصلات،کانالهای آبیاری و زهکشی مشکلاتی را بر سر راه تولید برنج قرار داده است.با اجرای طرح یکپارچه سازی نتنها...

2015
Jie Song Dongyan Cai Jinsong Deng Zhangquan Shen Marc A. Rosen

Urban land has increasingly expanded and encroached upon a significant number of paddy fields in Hang-Jia-Hu Plain, due to the rapid socio-economic development and agro-pedoclimatic conditions favorable to rice cultivation and human settlement. Although many studies have analyzed the characteristics of urban land expansion, relatively less attention has been paid to exploring the various urban ...

2016
Md Rokunuzzaman Yumiko Ueda Li Chen Sota Tanaka Kouhei Ohnishi

Soil bacterial community structures in terraced rice fields and abandoned lands in a hilly and mountainous area were analyzed using 16S rRNA gene sequences. The DGGE band patterns of each soil were similar. Based on pyrosequencing data, the richness and diversity of bacterial species were slightly higher in paddy fields than in other soils. A beta-diversity analysis clearly indicated that the b...

2012
Yi-Shiang Shiu

Most paddy rice fields in East Asia are small parcels, and the weather conditions during the growing season are usually cloudy. FORMOSAT-2 multi-spectral images have an 8-meter resolution and one-day recurrence, ideal for mapping paddy rice fields in East Asia. To map rice fields, this study first determined the transplanting and the most active tillering stages of paddy rice and then used mult...

Journal: :journal of agricultural science and technology 2010
h. filizadeh a. rezazadeh z. younessi

crop rotation is one of the essential practices in sustainable agricultural systems, be-cause of its effects on soil fertility and other benefits including a reduction in weed compe-tition. a field experiment was conducted at chaparsar rice research station, tonekabon, iran, from 2002 to 2003 to assess the influence of crop rotation, time of planting, and till-age depth on rice (oryza sativa l....

2001
Wataru TAKEUCHI Yoshifumi YASUOKA Masayuki TAMURA

Since the rapid increase in atmospheric methane was recognized in the early 1980’s, paddy fields have been considered to be one of the likely and most important sources of this problem. The objective of this study is to estimate the methane emission from paddy fields with remotely sensed data and the methane flux in situ. In this paper, firstly, we developed a scaling technique to extrapolate t...

2002
Changsheng Li Jianjun Qiu Steve Frolking Xiangming Xiao William Salas Berrien Moore Steve Boles Yao Huang Ronald Sass

[1] Decreased methane emissions from paddy rice may have contributed to the decline in the rate of increase of global atmospheric methane (CH4) concentration over the last 20 years. In China, midseason paddy drainage, which reduces growing season CH4 fluxes, was first implemented in the early 1980s, and has gradually replaced continuous flooding in much of the paddy area. We constructed a regio...

Journal: :Frontiers of earth science 2016
Cui Jin Xiangming Xiao Jinwei Dong Yuanwei Qin Zongming Wang

Information of paddy rice distribution is essential for food production and methane emission calculation. Phenology-based algorithms have been utilized in the mapping of paddy rice fields by identifying the unique flooding and seedling transplanting phases using multi-temporal moderate resolution (500 m to 1 km) images. In this study, we developed simple algorithms to identify paddy rice at a f...

2017
Weidong Man Hao Yu Lin Li Mingyue Liu Dehua Mao Chunying Ren Zongming Wang Mingming Jia Zhenghong Miao Chunyan Lu Huiying Li Mary J. Thornbush

Soil is the largest pool of terrestrial organic carbon in the biosphere and interacts strongly with the atmosphere, climate and land cover. Remote sensing (RS) and geographic information systems (GIS) were used to study the spatio-temporal dynamics of croplands and soil organic carbon density (SOCD) in the Sanjiang Plain, to estimate soil organic carbon (SOC) storage. Results show that cropland...

2007
Junichi Susaki

Laboratory experiments were conducted to measure microwave scattering on specimens to simulate paddy fields for the purpose of developing microwave scattering model of paddy fields. In the experiment, the specimens were produced into fiber reinforced plastic (FRP) tube with 70 x 60 x 60 cm volume. The specimens contained soils, water layer and paddy. X-band antennas measured the backscatter fro...

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