J. Fallahzade; M.A. Hajabbasi
Abstract
Abstract
Soil organic matter and its components are important factors in formation and stability of aggregates and subsequently soil structure. However data regarding organic matter distribution in soil aggregates is scarce, particularly in arid soils of Central Iran. The objective of this study was ...
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Abstract
Soil organic matter and its components are important factors in formation and stability of aggregates and subsequently soil structure. However data regarding organic matter distribution in soil aggregates is scarce, particularly in arid soils of Central Iran. The objective of this study was to investigate the distribution of organic carbon (OC), total nitrogen (TN), and carbohydrates in aggregates of different size classes (2–4, 1–2, 0.5–1, 0.25–0.5, 0.05–0.25 and
H. Shirani; M.A. Hajabbassi; M. Afyuni; A. Hemmat
Abstract
Abstract
Methods of tillage and organic matter affect root growth and distribution and therefore nutrient uptake by plant and its growth. This study was performed consecutive two years. Tillage treatments included disk harrowing + two disk harrowings as reduced tillage (15 cm plowing depth) and moldboard ...
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Abstract
Methods of tillage and organic matter affect root growth and distribution and therefore nutrient uptake by plant and its growth. This study was performed consecutive two years. Tillage treatments included disk harrowing + two disk harrowings as reduced tillage (15 cm plowing depth) and moldboard plowing + two disk harrowings as conventional tillage system (30 cm plowing depth). Also, three levels of 0, 30 and 60 tons per hectare farmyard manure were used as organic manure treatments. The above mentioned treatments were done in a split block design with 3 replications and under corn cultivation for two years. To determination of root morphological properties of plant, sampling was done by a cylinder with a cap from top of the row and root length and density were measured. The results showed, tillage systems had a significant effect (p=0.05) on root length and density of corn in 0-20 cm soil depth. In the reduced tillage treatment, root length and density in the stages of 9 and 11 leaves increased significantly in comparison conventional tillage, but root depth was higher at conventional tillage than reduced tillage. This is due to presence of soft soil (disturbed soil) in lower soil depth from top of the row under conventional tillage. The results indicated that manure had no significant effect on morphological root characteristics, but increased biological yield of corn.
Keywords: Reduced tillage, Conventional tillage, Farmyard manure, Corn root
A.A. Zolfaghari; M.A. Hajabbasi
Abstract
Abstract
Converting the forests and pastures to cultivated land results in loss of soil organic matter, deteriorating the soil structure, lowering hydraulic conductivity and increasing soil bulk density, which all cause increase in surface runoff and soil erosion. One of the soil physical properties ...
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Abstract
Converting the forests and pastures to cultivated land results in loss of soil organic matter, deteriorating the soil structure, lowering hydraulic conductivity and increasing soil bulk density, which all cause increase in surface runoff and soil erosion. One of the soil physical properties which intensify runoff is soil water repellency. To examine the effects of land use change on water repellency, soil samples were taken from two areas of central Zagros (e.g. pasture in Fereydunshar and forest in Lurdegan). In each area two different land uses were selected. One under cultivation and the other was unaltered and for each land use three sites were randomly selected. The effects of organic matter and soil water content on water repellency were investigated during January and July. The degree of water repellency of a soil was measured by using the water drop penetration time (WDPT) test. There was a strong relationship between soil water repellency and percentage organic matter in surface soils under forested areas. In January when the soil water content was between 18 to 22%, no actual water repellency was found in the forest. However, in July the water drop penetration time in sites 1, 2 and 3 in the 5 cm of the top soil was 130, 50 and 150 second, respectively, when the soil water content was only 5%. No soil water repellency was found in cultivated forest and pasture (cultivated pasture and undisturbed pasture). Changes in land use induced negative effects on water repellency. In this study, changing forest to cultivated land decreased organic matter content; mean weight diameter of soil aggregates, total porosity and hydraulic conductivity by 23, 55, 11 and 40%, respectively. Changing pasture to cultivated land decreased organic matter content; mean weight diameter and total porosity by 22, 40 and 9%, respectively. Changing forest and pasture to cultivated land increased bulk density of soil by 7 and 6%, respectively.
Key words: Changing land use, pasture, forest, water repellency
