نتایج جستجو برای: soil organic matter percent

تعداد نتایج: 638416  

Journal: :مدیریت خاک و تولید پایدار 0
حیدر غفاری دانشگاه تهران منوچهر گرجی دانشگاه تهران

maintaining soil productivity is one of the key factors in sustainable agriculture. soil erosion reduces soil productivity over a long-term period of time. therefore, determining soil erosion tolerance is necessary for sustainable agriculture production. in this study, the long-term effects of erosion on soil productivity in the typical kohin watershed were evaluated. the soil productivity inde...

Journal: :آب و خاک 0
محمد حسین روانبخش امیر فتوت غلامحسین حق نیا

abstract a study was conducted to evaluate the effect of incubation time, sewage sludge and clay content on the distribution of nickel and cadmium in different fractions of selected calcareous soils. to meet this purpose, an experiment with two different soils (4 and 30 percent caco3), two different textures (8 and 40 percent clay), two levels of nickel (0 and 100 mg.kg-1), two levels of cadmiu...

2013
McHenry

Organic farming systems still depend on intensive, mechanical soil tillage. Frequent passes by machinery traffic cause substantial soil compaction that threatens soil health. Adopting practices as reduced tillage and organic matter retention on the soil surface are considered effective ways to control soil compaction. In tropical regions, however, the acceleration of soil organic matter decompo...

2013
Ahmad Gholamalizadeh Ahangar

Recently sorption of organic pollutants, in particular polycyclic aromatic hydrocarbons (PAHs), has received much attention and researchers agree that organic matter (the amount of organic matter and its nature) is the most important factor affecting the sorption, desorption and fate of organic pollutants in soil and sediments. It is well documented that organic matter of soil and sediments is ...

2002
I. C. Burke D. S. Schimel

Soil organic C content, a major source of system stability in agroecosystems, is controlled by many factors that have complex interactions. The purpose of this study was to evaluate the major controls over soil organic carbon content, and to predict regional patterns of carbon in range and cultivated soils. We obtained pedon and climate data for 500 rangeland and 300 cultivated soils in the U.S...

The land-use change, cutting forest trees and the grasslands conversion to agricultural lands destroyed natural ecosystems and also current or future production capacity reduce and these are harmful effects on the soil physicochemical characteristics. This study taken with aim, checking the role of forest-land change on some soil physical-chemical characteristics and then identify some effectiv...

2017
Gary E. Varvel Mark A. Liebig John W. Doran

Assessing effects of cropping systems on soil organic matter (SOM) and soil carbon (C) changes are necessary to make accurate projections regarding sequestration and emission of CO2 by agricultural soils. This process requires substantial annual management inputs and large outlays for soil sampling and analyses. Our objectives were (1) to evaluate and test an alternative method for soil organic...

Journal: :تحقیقات آب و خاک ایران 0
علیرضا خداشناس دکتری، مرکز تحقیقات کشاورزی و منابع طبیعی خراسان رضوی علیرضا کوچکی استاد، دانشگاه فردوسی مشهد پرویز رضوانی مقدم استاد، دانشگاه فردوسی مشهد امیر لکزیان دانشیار، دانشگاه فردوسی مشهد مهدی نصیری محلاتی استاد، دانشگاه فردوسی مشهد

soil quality is the most suitable index to an assessment of the stability of terrestrial ecosystems, especially agro-ecosystems. to determine the effects of agricultural practices on soil organic matter, species richness and abundance of soil invertebrates, a study was conducted in three regions of razavi and northern khorasan provinces, iran. soil were taken from in each winter wheat field of ...

ژورنال: علوم آب و خاک 2012
عطااله کاویان, , قربان وهاب‏زاده, , مریم رضایی پاشا, ,

As the first event in soil erosion, rain splash erosion causes movement of soil fragments. Splash is an important process in interrill erosion. The amount of soil particles detached from the surface is associated with soil and rain characteristics and may be affected by rainfall erosivity and soil erodibility. Therefore, in this study, splash erosion rate and its relation with some soil propert...

Journal: :محیط زیست طبیعی 0
علیرضا خداشناس مرکز تحقیقات کشاورزی و منابع طبیعی خراسان رضوی، ایران علیرضا کوچکی گروه زراعت، دانشکده کشاورزی، دانشگاه فردوسی مشهد، ایران پرویز رضوانی مقدم گروه زراعت، دانشکده کشاورزی، دانشگاه فردوسی مشهد، ایران امیر لکزیان گروه خاکشناسی، دانشکده کشاورزی، دانشگاه فردوسی مشهد، ایران

soil biodiversity is the origin of considerable goods for maintenance and extension of above ground biodiversity and environmental soundness. this study was carried out in shirvan, mashhad and gonabad, three regions of razavi and northern khorasan provinces, to determine soil characteristics and biodiversity in natural systems of arid and semi-arid regions. in each studied system, 10 locations ...

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