نتایج جستجو برای: soil fixation
تعداد نتایج: 231700 فیلتر نتایج به سال:
Sugarcane (Saccharum officinarum L.) and rotational crops have been cultivated without potassium fertilizers for many years in southwestern Iran. Although potassium was removed from this soil, no response has been reported to K fertilizers by crops. This study was conducted to evaluate the effects of wetting and drying, and cultivation systems on potassium fixation in some Khouzestan soils. Th...
Potassium (K) fixation by phyllosilicates clay minerals is a very important process influencing the availability of K for plants. Information about K fixation is limited in Hamadan soils. The objectives of this research were to determine potassium fixation capacity (PFC) and potassium fixation index (PFI) of 10 surface soils of Hamadan province and the correlation of these parameters with soil ...
This study was done to compare K+ and NH4+ fixation in different agricultural systems in Khuzestan province. Soil samples were collected from Shushtar and Abadan. Samples were collected from depths of 0-30 and 30-60 cm in sugarcane, multi cropping, palm and uncultivated land. Then, 0-50-100-200-400-600-800-1000 mg kg-1 K+ or NH4+ concentrations were added to 0.5 gram of clay separated from thes...
ABSTRACT- The present research was conducted to study K forms and fixation in soils of southern Iran (Hormozgan Province) with aridic and aridic-ustic regimes and to address the relations between soil mineralogy and potassium forms. Thirteen surface soil samples (0-25 cm) were collected from different regions and analyzed in laboratory. Illite and feldspar and mica are the major clay and soil m...
Najafi-Ghiri M., Abtahi A. (2013): Potassium fixation in soil size fractions of arid soils. Soil & Water Res., 8: 49–55. Amounts of potassium (K) fixed in soil fractions of 10 calcareous soils of southern Iran were measured to evaluate the contributions of different soil size fractions to K fixation. Soil particles were fractionated after dispersion of the soils with an ultrasonic probe. Potass...
Seasonal distribution of nitrogen fixation by Spartina alterniflora epiphytes and in surface and soil samples was investigated in a Georgia salt marsh which was amended with sewage sludge or with glucose and/or ammonium nitrate. There was no significant difference between the rates of fixation in the unamended and sewage sludge plots. Additional perturbation experiments suggested that nitrogen ...
Sugarcane (Saccharum officinarum L.) and rotational crops have been cultivated without potassium fertilizers for many years in southwestern Iran. Although potassium was removed from this soil, no response has been reported to K fertilizers by crops. This study was conducted to evaluate the effects of wetting and drying, and cultivation systems on potassium fixation in some Khouzestan soils. Th...
niIicrobial fixation of atmospheric nitrogen was ~neasured in soil amended with ground wheat straw and incubated a t two moisture levels (field capacity and \vaterlogged). Fixation equivalent to 42-52 kg/ha in the soil a t held capacity and 13-150 I;g/ha in the waterlogged soil was observed using 15N techniques when the soil was amended with lyo straw or less. Using both I5N and ICjeldahl techn...
چکیده ندارد.
The effects of H2 gas treatment of an agricultural soil cultivated previously with a mixture of clover (Trifolium pratense) and alfalfa (Medicago sativa) on CO2 dynamics and microbial activity and composition were analyzed. The H2 emission rate of 250 nmol H2 g K1 soil h was similar to the upper limit of estimated H2 amounts emitted from N2 fixing nodules into the surrounding soil ([Dong, Z., L...
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