نتایج جستجو برای: soil erosion and decreasing of soil fertility

تعداد نتایج: 24078045  

1999
Ephraim Nkonya Andrew Barkley Steve Hamilton Daniel Bernardo

This paper develops a soil conservation model that is relevant to smallholder farmers who applylittle or no fertilizer. Empirical results drawn from northern Tanzania imply that, ignoringfertility mining problem in model specification leads to overestimation of profits for farms thatapply little or no fertilizer. The model also shows that, the impact of output price on soilc...

2006
Carleton S. White Rosemary L. Pendleton Burton K. Pendleton

Prescribed fire was used in two semiarid grasslands to reduce shrub cover, promote grass production, and reduce erosional loss that represents a potential non–point-source of sediment to degrade water quality. This study measured transported soil sediment, dynamics in soil surface microtopography, cover of the woody shrub, grass, and bare ground cover classes, and soil fertility measured by nit...

Journal: :مرتع و آبخیزداری 0
حشمت اله آقارضی عضو هیئت علمی مرکز تحقیقات کشاورزی و منابع طبیعی استان مرکزی مهدی مردیان دانشجوی دکتری آبخیزداری دانشگاه علوم کشاورزی و منابع طبیعی ساری علی اکبر داوودی راد دانشجوی دکتری آبخیزداری دانشگاه تربیت مدرس و عضو هیئت علمی مرکز تحقیقات کشاورزی و منابع طبیعی استان مرکزی داوود نیک کامی دانشیار پژوهشکدة حفاظت خاک و آبخیزداری

land use optimization using linear programing is a method in watershed management for access to production sustainability and decreasing of soil erosion. the sensitivity analysis of the model can with investigation of results influence form changes in input parameters, lead to decrease the uncertainty in decision-making of management programs. so in this research, linear programming model using...

Activities to reduce soil erosion, soil fertility and increasing agricultural production and finally crop income have considered fundamental in the implementation of sustainable agriculture in Iran. This research investigates the effects of no-till (NL) technology to reduce soil erosion and increasing agricultural income and eventually for achieving sustainability. Data were collected through q...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده مهندسی علوم آب 1393

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده کشاورزی 1394

with the increasing population and the need for more food, as well as with the development of science and technology, human approach to unnatural and often chemical inputs to increase agricultural production has been a great expansion and problems such as increased cancers, chronic diseases has created environmental pollution. implementation of organic organic is a solution to these problems . ...

Journal: :اکو هیدرولوژی 0
محسن خورسند دانشجوی کارشناسی ارشد، گروه مهندسی آبخیزداری، دانشکدۀ منابع طبیعی دانشگاه تربیت مدرس، نور عبدالواحد خالدی درویشان استادیار، گروه مهندسی آبخیزداری، دانشکدۀ منابع طبیعی دانشگاه تربیت مدرس، نور مهدی غلامعلی فرد استادیار، گروه محیط زیست، دانشکدۀ منابع طبیعی دانشگاه تربیت مدرس، نور

the presentstudy aimed to compare the annual soil loss prediction of rusle model with the soil erosion measurements using erosion pins and plots in khamesan representative watershed, kurdistan province. for this purpose, the distributed annual soil loss was estimated by rusle model. the suspended sediment samples were then collected daily for one year (2015/7 to 2016/6) in hydrometry station at...

Journal: :مرتع و آبخیزداری 0
جلال زندی دانشجوی دکتری آبخیزداری دانشگاه علوم کشاورزی و منابع طبیعی ساری محمود حبیب نژاد روشن استاد گروه آبخیزداری دانشگاه علوم کشاورزی و منابع طبیعی ساری کریم سلیمانی استاد مرکز rs و gis دانشکدة منابع طبیعی ساری

soil erosion is a serious environmental problem in vazroud watershed, which is located in the centre of the mazandaran province, iran. unfortunately, vazroud watershed like most iran watersheds don’t have recorded data and erosion and sedimentation gages to research, monitor and model soil erosion at large watershed. in order to assess the soil erosion risk, soil erosion modeling at the watersh...

Investigation about the influence of land-cover and land use changes on soil erodibility potential, case study: Gharesou, Gorganrood Land use and land cover (LUC) change associated with climatic and geomorphologic conditions of the area have an accelerating impact on the land degradation. Natural as well as human-induced land use land cover change (LUCC) has significant impacts on regional soi...

Introduction Water erosion is one of the most important factors in land degradation in large parts of Iran destroying fertile soils and agricultural land. The impact of soil erosion and related sediments decreases significantly water quality and reservoir capacity. Especially in semiarid areas like in the Menderjan watershed in the west Isfahan province sheet and rill erosion contributes to th...

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