Showing 4 results for Soil Properties.
F. Salehi, M. J. Bahrani, S. A. Kazemaini, H. Pakniyat, N. A. Karimian,
Volume 15, Issue 55 (4-2011)
Abstract
Crop residues are beneficial substances that can bring about important changes in soil biological, chemical and physical properties and can also increase or stabilize crops yield. A field experiment was carried out at Research Station of College of Agriculture, Shiraz University, Shiraz, Iran, to determine the effects of wheat (Triticum aestivum L.) residue rates in combination with N levels on some soil properties in common bean (Phaseolus vulgaris L.) cultivation for two years (2008-2009). The experiment was conducted as split split-plot arranged in a completely randomized blocks design with three replications. Treatments were two red bean cultivars as main plots, N levels (0, 34.5, 69, and 103.5 kg ha-1) as sub-plots and residue rates (0, 25, 50 and 75%) as sub sub-plots. The results showed that application of crop residues significantly increased soil organic carbon, N, K, and P contents. Heavy crop residue (75%) application had no effects on these soil properties. Thus, retaining 50% crop residue was optimum for proper soil quality. Increased N application increased soil N, decreased P and K contents, and had no effects on organic carbon.
H. R. Owliaie, E. Adhami, H. Faraji, P. Fayyaz,
Volume 15, Issue 56 (7-2011)
Abstract
Trees in many forests affect the soils below their canopies. Analysis of the relationships between trees and soil is one of the basic factors in management and planning of forests. Zagros forest ecosystem is one of the main degrading forest ecosystems in Iran and plays an important role in soil protection. Quercus brantii is the most important woody species in these forests. This study was conducted to determine the influence of oak on selected physico-chemical properties of soils of three oak forests in Yasouj region. The experimental design was a factorial 332 (3 depths, 3 regions and 2 distances) in a randomized complete block design with four replications. Soil samples (0-20, 20-40 and 40-60 cm depth) were taken from beneath canopies and adjacent open areas. The results showed that oak canopy increased mostly organic carbon, total N, available K, P, EC, EDTA extractable Fe, Zn and Mn, while CCE, pH, and DTPA extractable Cu were decreased. Oak canopy had no significant effect on soil texture. Our results suggested that the presence of Quercus brantii individuals may be an important source of spatial heterogeneity in these forests.
Z. Fahim, M. A. Delavar, A. Golchin,
Volume 17, Issue 63 (6-2013)
Abstract
Organic carbon is the most important component of terrestrial ecosystems and any change in its abundance can have a major impact on the processes that take place in ecosystem. The aim of this study was to estimate carbon sequestration in three different elevations (200 to 1200 m from sea level) and according to vegetation type in the Khairoodkenar forest. The highest carbon sequestration was observed in the surface layer of a soil with Fig-Carpinus betulus vegetative cover and it was estimated to be 167.4 ton/ha. But when carbon sequestration was measured in soil solum, it was found that soils with Fagus orientalis-Carpinus betulus vegetation cover had the highest amount of organic carbon (514.4 ton/ ha). The results showed that clay fraction had the highest carbon content but the highest enrichment factor (1.59) was measured for sand fraction in soils with Fagus orientalis- Carpinus betulus vegetative cover. The highest organic carbon content (7.89%) and aggregate stability (MWD= 7.79mm) and lowest bulk density (1.21 g/cm3) were measured in soils with Figs- Carpinus betulus vegetative cover.
Mahnaz Zarea Khormizi, Ali Najafinejad, Nader Noura, Ataollah Kavian,
Volume 17, Issue 64 (9-2013)
Abstract
Soil erosion is one of the most important factors affecting soil quantity and quality and is environmental problems in developing countries like Iran. It can have deteriorating effects on ecosystems. This research was carried out in farm lands of the Chehel-Chai watershed, Golestan province to investigate the effect of soil properties on runoff and soil loss. Runoff and soil loss were measured in a completely randomized design in 36 plots with 10×10 m sizes in farm lands. For this reason, this study was conducted using rainfall simulator with 2 mm/min intensity and 15 min duration in 4 replicates. Soil samples were also taken in each plot. Sampling was conducted in October 2009. Results of the Pearson correlation showed that among soil properties, the contents of the lime, silt and fine sand had positive correlations with runoff at 1% confidence level. Also, soil surface resistance at 1% confidence level, the contents of the organic matter and nitrogen at 5% confidence level had negative correlations with soil loss. Finally, the results of multiple linear models showed that the content of lime is effective in estimating runoff and soil surface resistance, and organic matter is effective in estimating soil loss.
