Showing 2 results for Paddy Soil.
M. Alizadeh, F. Mirzaii, T. Sohrabi , M. Kkavosi , M. R Yazdani,
Volume 17, Issue 66 (2-2014)
Abstract
Water management in cracked paddy soils is an important issue in rice cultivation. In order to study organic matter and zeolite effect and their interaction on moisture conditions and hydraulic and physical properties of paddy soils, the organic matter (rice straw) at four levels (0, 8, 16 and 24 tons per hectare), zeolite at four levels (0, 0.5, 1 and 1.5 percent ), and also moisture stages of soil at 5 levels were selected. This experiment was conducted in Rice Research Institute of Iran. Randomized Complete Block Design (RCBD) was used to study the effect of treatments on different subjects. The amount of moisture, bulk density and the distance of soil from the wall of container were measured in a 4-month period. The obtained results showed that the interaction effects of organic matter and zeolite on soil moisture content were statistically significant at one percentage level. Addition of plant residues caused an increase in soil moisture weight and reduction in bulk density compared to the control treatment. It was also found that soil moisture content and bulk density were highly correlated. Bulk density of control treatment ranged from 0.75 to1.7 gr/cm3, while with addition of 1.5 % crop residue the bulk density ranged from 0.7 to 1.3gr/cm3. Overall results show that crop residues are effective in reduction of crack parameters of soil , but zeolite cannot be effective although it causes more maintenance of soil moisture.
H. R. Owliaie, M. Najafi Ghiri,
Volume 18, Issue 70 (3-2015)
Abstract
Topography and land use are among the most important factors affecting the soil formation. Chemical forms of Fe and magnetic susceptibility (χ) are widely used for the evaluation of soil development. This study was conducted in order to determine the effect of these factors on χ. A toposequence was selected in Madvan Plain, Northern Yasouj. Nine soil profiles (paddy and dryland soils) were dug and sampled from diagnostic horizons. Magnetic susceptibility was measured by Bartington Dual Frequency, MS2 Meter at frequencies of 0.46 and 4.6 KHz. Results indicated that less amounts of χ, frequency dependence of χ (χfd%) and CBD extractable Fe (Fed) (3.1, 2.6 and 2.7 times, respectively), and more quantities of oxalate extractable Fe (Feo) and Feo/Fed ratio (5 and 7.2 times, respectively) were measured in paddy soils. The highest value of χ was observed in pedons located on plateau and piedmont plains, and the lowest belonged to those located on river terraces with aquic conditions. Compared to paddy soils, χ enhancement at soil surface was greater (17%) in dryland soils. A positive correlation existed between χ and some soil characteristics such as Fed, clay content and χfd%.
