Showing 4 results for Yasrebi
J. Yasrebi, N. Karimian, M. Maftoun, A. Abtahi, A. Ronaghi, M. T. Assad,
Volume 7, Issue 4 (winter 2004)
Abstract
Twenty-five surface samples of calcareous soils of Fars Province were used to study the distribution of different nitrogen (N) forms to determine the relationship between the N forms and soil charcteristics, and to obtain regression equations for prediction of N forms from soil characteristics. The forms determined were: soil total nitrogen NO3-N by phenol disulfunic acid NO3-N extractable by 2 M KCl NH4-N extractable by 2 M KCl, 1 N sulfuric acid, and 0.25 N sodium hydroxide oxidative released N by acid permanganate and alkaline permanganate and NH4-N extractable by 2 M KCl at 100 oC. The highest amount of N was that released by alkaline permanganate which constituted 4.47% of soil total N and the lowest form was exchangeable NH4+ which amounted to only 0.6% of total N. Water soluble and exchangeable forms accounted for less than 2% of total N. Highly significant correlations were found between total N and acid permanganate-N (r=0.931) and total N and alkaline permanganate-N (r=0.850). Highly significant regression equations were obtained for prediction of soil total N, acid permanganate-N, and alkaline permanganate-N from soil organic matter (OM), which is an indication of a close relationship of these N forms with OM.
M. Zahedifar , N. Karimian , A. Ronaghi , J. Yasrebi , Y. Emam ,
Volume 14, Issue 54 (winter 2011)
Abstract
The effect of phosphorus (P) (0, 25, and 50 mg kg-1 soil as Ca(H2PO4)2) and organic matter (OM) (0, and 2% w/w feedlot cattle manure) on P and zinc (Zn) distribution in different parts of wheat plant (Triticum aestivum L.) at various growth stages and its relationship with soil P and Zn were determined in greenhouse condition. In all pots, shoot P concentration decreased as plant growth proceeded. Phosphorus concentration of shoot and flag leaf decreased from 7th to 9th stage of growth, whereas that of spickle increased. Spickle P uptake and Zn uptake of stem, shoot, flag leaf, and spickle increased with proceeding of wheat growth. Phosphorus uptake of shoot increased from 3th to 9th growth stages, whereas P uptake of stem and flag leaf decreased from 7th to 9th growth stages. Soil P and Zn concentrations increased with application of P and OM and plant growth. The trend of P and Zn changes in shoot, stem and flag leaf was similar. It is, therefore, concluded that analyzing flag leaf for P and Zn concentrations be used for prediction of plant nutritional status of those nutrient elements in cases where such information is needed.
M. Zolfi Bavariani, A. Ronaghi, N. Karimian, R. Ghasemi, J. Yasrebi,
Volume 20, Issue 75 (Spring 2016)
Abstract
This study was conducted to investigate the effects of poultry manure (PM) and its derived biochars on chemical properties of a sample calcareous soil. Poultry manure and its derived biochars at 200(B200), 300(B300) and 400(B400)°C were incorporated with 400 g of soil at 2% level (w/w) and incubated for 150 days. Some chemical properties of soil and bio-availability of some nutritional ingredients such as phosphorous, potassium, iron, manganese, zinc and copper were determined at different times of incubation. Soil nutrients availability, organic carbon (OC), electrical conductivity (EC) and cation exchange capacity (CEC) increased by addition of all these organic substances. Biochars prepared at higher temperatures were more effective in increasing soil OC and its durability. Addition of PM and B200 decreased soil pH, whereas B400 increased it. Although highest soil EC was observed in B300 and B400 treated samples in the early stages of incubation, the rate of increasing in soil EC was higher at PM and B200 treated samples. In general, it was concluded that biochar prepared at 300°C had the highest effect on availability of nutrients and their durability in the soil.
M Zolfi Bavariani, A. Ronaghi, N. Karimian, J. Yasrebi, Reza Ghasemi,
Volume 21, Issue 1 (Spring 2017)
Abstract
This study was conducted to investigate the effects of poultry manure (PM) and derived biochars on phosphorous (P) availability and apparent recovery in a calcareous soil. Treatments consisted of four rates of P (0, 30, 60 and 90 µgg-1) and five organic substances (blank, poultry manure and derived biochars at 200, 300 and 400°C). organic substances were incorporated with 400 g of soil at 2% level (w/w). All soil treated samples plus control were incubated for 150 days. Soil P availbility determined at 8 different stage of incubation time period. Phosphorous availability was less in untreated soil samples with organic substances and also decreased with time. Although P recovery from inorganic P fertilizer was high in the early stages of incubation time compared to treated soil samples but decreased with time, if not treated with organic substances. Phosphorus availability and recovery increased with time in PM and biochares treated soil samples. Simultanous application of inorganic P and organic substances decreased apparent P recovery. Negative interaction obsorved between organic substances and high rates of inorganic P fertilizer on P availability. It was concluded that PM biochar prepared at 300°C had the highest effect on adjusting P availability in calcareous soil.
