نتایج جستجو برای: conservation of soil

تعداد نتایج: 21196506  

Journal: :Journal of Range Management 1971

2007
Jay B. Norton

In dryland cropping systems, optimal yields require that nutrient supply matches the soil’s yield potential supported by available moisture. Conservation tillage systems that leave at least 30 percent of the soil surface covered by residue dramatically increase moisture retained in the soil compared to crop-fallow systems. This enables producers to plant two, three, or four consecutive crops, o...

2007
G. B. Runion S. A. Prior H. H. Rogers H. A. Torbert

Elevated atmospheric carbon dioxide (CO2) can affect both the quantity and quality of plant tissues produced, which will impact the cycling and storage of carbon (C) within plant/soil systems and thus the rate of CO2 release back to the atmosphere. Research is needed to more accurately quantify the effects of elevated CO2 and associated feedbacks on soil CO2 efflux in order to predict the poten...

2005
Subhrendu Pattanayak Evan Mercer

Trecs can he considered as investments made by economic agents to prevent depreciation of natural assets such as stocks of top soil and water. In agroforestq systems farmers use trees in this manner by deliberately combining them with agricultural crops on the same unit of land. Although advocates of agroforestry have asserted that soil conservation is one of its primary henefits, empirical est...

Journal: :Environmental Modelling and Software 2010
Michael J. White Daniel E. Storm Philip R. Busteed Michael D. Smolen Hailin Zhang Garey A. Fox

In the United States, government sponsored conservation programs are under increasing pressure to quantify the environmental benefits of practices they subsidize. To meet this objective, conservation planners need tools to accurately predict phosphorus (P) loss from agricultural lands. Existing P export coefficient based tools are easy to use, but do not adequately account for local conditions....

Journal: :مرتع و آبخیزداری 0
کاظم نصرتی دانشیار دانشکدة علوم زمین دانشگاه شهید بهشتی فروزان احمدی دانشجوی دکتری ژئومورفولوژی - مدیریت محیطی، دانشگاه شهید بهشتی علی اکبر نظری سامانی دانشیار دانشکدة منابع طبیعی دانشگاه تهران محمد رضا ثروتی استاد دانشکدة علوم زمین دانشگاه شهید بهشتی

soil erosion is one of the most destructive phenomena which cause significant ecological changes in many areas. soil conservation and erosion control is essential because of the irreparable damage caused by soil erosion. soil conservation programs will not achieve until to find adequate methods of combating land degradation and ways to reduce the sediment. therefore, we need to have enough know...

137Cs technique for determining soil particles redistribution is of tremendous importance considered by most soil and water conservation experts. Due to time and monetary limitations for spectrometry in the lab, a portable High Pure Germanium Detector was used in this study. For this, Kachik paired subcatchments were chosen and 60 positions in each subcatchment were used for spectrometry analys...

Journal: :journal of agricultural science and technology 2014
r. erfanzadeh r. shahbazian h. zali

seed bank is a central topic for plant community restoration. we determined the potential and regeneration capacity of soil seed banks of woody plant patches in conservation of the vegetation in an alpine habitat, since vegetation has completely disappeared in some sites by intensive grazing in the habitat. the study was done in mountainous area of alborz in iran. a total of 20 individual shrub...

ژورنال: آبخیزداری ایران 2020
Gholami, Leila, Hasanzadeh, Negar, Khaledi Darvishan, Abdulvahed, Yonesi, Habibolah,

Soil is very important for the production of crops and foodstuffs. One of the most important environmental crisesin the relationship with soil is the phenomenon of soil loss and therefore the soil conservation is very important. In conditions that, there is not the possibility of establishing vegetation, the use of soil conditioners can be useful in controlling soil loss. The present study wa...

2010
Martin AN Anikwe

BACKGROUND Changes in agricultural practices-notably changes in crop varieties, application of fertilizer and manure, rotation and tillage practices-influence how much and at what rate carbon is stored in, or released from, soils. Quantification of the impacts of land use on carbon stocks in sub-Saharan Africa is challenging because of the spatial heterogeneity of soil, climate, management cond...

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