Showing 3 results for Mahbobi
H. Bayat, A.a. Mahbobi, M.a. Hajabbasi, M.r. Mosaddeghi,
Volume 11, Issue 42 (winter 2008)
Abstract
Tillage is one of the important managing factors that can destroy or improve soil structure. Soil structure is affected by the machines and shape of the wheels. Field experiments were conducted at Hamadan Agricultural Research Station on a coarse loamy mixed mesic Calcixerolic Xerocrepts soil to measure and evaluate the effects of tillage and wheel-induced compaction on selected soil physical properties. Treatments included tillage methods (Moldboard Plow and Chisel Plow, (MP, CP)) performed using three customary tractors in Iran [John Deer (J), Romany (R) and Massey Ferguson ( MF) ]. Traffic zone and non traffic zone were other treatments. A split-plot design with three replications was used in a completely randomized arrangement of treatments. Soil samples were taken at the end of wheat growth season in traffic and non- traffic zone and from four layers and compared for bulk density (BD), cone index (CI), and mean weight diameter (MWD). The influence of both tillage methods on BD in most soil depths was not significant, meanwhile, BD was higher in the deeper layers. Wheel traffic did not affect BD significantly, but its effect decreased by increasing the depth. Commonly, conservation tillage increased structural stability as evaluated by MWD. Cone index illustrated the same trend as for BD, with some variation because of it higher sensitivity, so it was significantly was increased in CP rather than in MP for the traffic zone. Such a difference was not observed in non-traffic zone. The CI was also significantly increased in traffic zone compared with non-traffic zone. J significantly increased CI in two first layer in comparing with MF, but there was not significant difference between J and R. The MWD was increased by chisel plow in non-traffic zone and this increment was significant in fourth soil layer (22.5- 30 cm). Wheel traffic caused the increase of MWD in the second layer and significant difference was not observed in other layers. Overall, R caused less destruction in soil structure and tillage methods changed some of soil physical properties.
S Zandsalimi, M Mosadeghi, A Mahbobi,
Volume 12, Issue 46 (1-2009)
Abstract
Organic fertilizers are the sources of many human-pathogenic microorganisms which potentially threaten the human health. This study was carried out to explore the possible effects of soil and manure types on filtration, transport and fate of manure-borne bacteria through undisturbed soil columns. The manure treatments consisted of cow manure, poultry manure and sewage sludge which were distributed at the rate of 10 Mg ha-1 on the surfaces of intact columns of two sandy clay loam and loamy sand soils. The manure-treated soil columns were leached by tap water with similar unsaturated flux of 4.8 cm h-1 up to four pore volumes (PV). The influent and leachate were sampled at different PVs. Gram-negative bacteria concentrations were determined for the influent and the columns’ leachate. Average influent concentration, average effluent concentration, relative filtration, and transported bacteria fraction during the leaching events were determined. Significant differences (P<0.05) were observed between the poultry manure and the other two manures in terms of average influent (i.e. manure-released) bacteria concentration. Stable structure and preferential pathways facilitated the bacteria movement in the sandy clay loam soil columns. The loamy sand soil strained 1.45 times more bacteria than the sandy clay loam soil due to its weak structure and blocked-dead pores. Relative contamination of the effluent was higher for poultry manure when compared with the other fertilizers. The low ionic strength of sewage sludge suspension caused the lower filtration of bacteria through the soil columns. The high concentration of soluble organics in cow manure resulted in a relative transport of the bacteria 1.12 times greater than the poultry manure. In general, management of organic fertilizers especially household poultry manure, as a considerable source of pathogenic bacteria, is important to control the environmental risks of pathogenic pollutions. Moreover, the soil texture and structure significantly affected the fate of manure-borne bacteria.
M Jalali Hajiabadi, A Sadeghi, N Mahbobi Sofiani, M Chamani, Gh Riazi,
Volume 13, Issue 47 (4-2009)
Abstract
In order to study the effects of L-carnitine on performance and some blood biochemical parameters of rainbow trout, the present experiment was conducted with 144 fish (130±5 g) for 8 weeks. In a completely randomized design, the experimental fish were divided into 9 groups with 3 treatments and 3 replicates and 16 fish in each group. Levels of L-carnitine supplements were 0 (control), 1 and 2 g per kg of diet. Results indicated that specific growth rate (SGR), total body weight, weight gain and protein efficiency ratio (PER) were significantly increased by 1g/kg L-carnitine supplements (P<0.05). L-Carnitine also improved feed conversion ratio (FCR) of fish. Crude protein of fish fillet was increased, but its crude fat was reduced at 1g/kg L-carnitine treatment. Similarly, cholesterol, total protein, albumin and globulin of fish blood serum were significantly (P<0.05) increased by the same levels of L-carnitine in the diet, however, blood glucose level remained unchanged. L-Carnitine reduced visceral fat index and increased hepatosomatic index. In conclusion, the results of the present study indicated that the addition of 1g L-carnitine per kg of diet could improve the performance of rainbow trout at grower stage.
