نتایج جستجو برای: soil solution

تعداد نتایج: 639736  

2004
Sylvie Recous Ian R.P. Fillery Daniel V. Murphy Lars S. Jensen

We compared gross N fluxes by N pool dilution in a coarse-textured agricultural soil when N was applied to the soil NH4 C pool by either: (i) mixing a NH4NO3 solution into disturbed soil or (ii) injection of NH3 gas into intact soil cores. The two techniques produced similar results for gross N mineralization rates indicating that NH4 C production in soil was not altered by soil disturbance, me...

2014
Šárka Hřibová Helena Zlámalová Gargošová Milada Vávrová

From the physical point of view, soil is a heterogenic polydisperse system. It often becomes a place of a secondary contamination during extinguishing uncontrolled areal fires in nature. Foam extinguishing agents (FEAs), used at these events, basically contain surface active substances and perfluorinated compounds. These tend to be captured in the soil matrix due to their specific properties. C...

2006
Uwe Schleiff

Due to the lack of good quality water for human consumption and industry, in many countries irrigated agriculture is exposed to increasing pressure to expand the use of brackish and even high-saline waters for crop production. The application of lower quality waters requires special management practices, which are not yet fully understood with respect to optimization of plant growth on saline s...

Journal: :Journal of environmental quality 2003
Mark Fuhrmann Mitch Lasat Stephen Ebbs Jay Cornish Leon Kochian

Phytoextraction field experiments were conducted on soil contaminated with 0.39 to 8.7 Bq/g of 137Cs to determine the capacity of five plant species to accumulate 137Cs and the effects of three soil treatments on uptake. The plants tested were redroot pigweed (Amaranthus retroflexus L. var. aureus); a mixture of redroot pigweed and spreading pigweed (A. graecizans L.); purple amaranth (A. crute...

2008
Sabine Goldberg Donald L. Suarez Peter J. Shouse

Boron (B) adsorption on two arid-zone soils from the San Joaquin Valley of California was investigated as a function of equilibrium solution B concentration (0–250 mg L), solution pH (3–12), and electrical conductivity (EC, 0.3 or 7.8 dS m). Boron adsorption on both soils increased with increasing pH, reached a maximum near pH 9, and decreased with further increases in pH. Boron adsorption as a...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بوعلی سینا - دانشکده علوم پایه 1391

abstract: in this thesis, we focus to class of convex optimization problem whose objective function is given as a linear function and a convex function of a linear transformation of the decision variables and whose feasible region is a polytope. we show that there exists an optimal solution to this class of problems on a face of the constraint polytope of feasible region. based on this, we dev...

2014
Leticia S. Sonon David E. Kissel Uttam Saha

What are Cation Exchange and Cation Exchange Capacity? Soil clay minerals and organic matter tend to be negatively charged, thus attracting positively charged ions (cations) on their surfaces by electrostatic forces. As a result, the cations remain within the soil root zone and are not easily lost through leaching. The adsorbed cations may easily exchange with other cations in the soil solution...

Journal: :journal of agricultural science and technology 2011
a. samadi

solution potassium (so-k) and exchangeable k (ex-k) extracted by nh4oac are the major sources of potassium used by plants, but initially non-exchangeable k (nex-k) can also contribute significantly to plant uptake. perennial ryegrass (lolium perenne, cv. roper) was successively planted in ten surface soil samples with different clay mineralogical composition belonging to five soil types to dete...

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