Showing 2 results for A. Samadi
Sh. Mahmood-Soltani, A. Samadi,
Volume 7, Issue 3 (fall 2003)
Abstract
Knowledge of forms of phosphorus (P) is important in the evaluation of soil P status and also in understanding soil genesis and fertility. Amounts and distribution of P in different organic and inorganic fractions were examined in 39 soil samples of Fars province. Soils were sequentially extracted to determine organic P and inorganic P fractions.
Total P with an average of 597 mg/kg soil was lower in the light soils (482 mg/kg) as compared with the heavy soils (690 mg/kg). Organic P constituted considerable portions of TP (27%). Calcium phosphates with an average of 424 mg/kg soil and being comprised of 71% inorganic P was the dominant form of soil phosphorus. Simple regression analysis indicated that there were significant positive relationships between organic P, Ca phosphates and Al-Fe phosphate values with CEC and clay content. Stepwise multiple regression analysis showed that a combination of soil properties such as clay content and equivalent calcium carbonate (CCE) increased correlation coefficients (R). Alghough multiple regression model was significant (at P<0.05), the relative contribution of each soil property in Al-Fe-P fraction was not considerable.
N. Miran , A. Samadi,
Volume 16, Issue 61 (fall 2012)
Abstract
To establish DRIS norms in sugar beet (Beta Vulgaris L.) and compare them with DOP index, leaf samples were collected from 57 fields and N, P, K, Ca, Mg, Fe, Mn, Zn, Cu and B concentrations were determined. On the bases of crop yield, the fields were divided into two groups with low and high yielding performances. Standard DRIS norms were established for the different nutrient ratios. DRIS indices were calculated to evaluate nutrient balances and order of nutrients requirements. Sufficiency ranges of macro and micro nutrients were derived by DRIS technique. DRIS-derived sufficiency ranges were 3.0-5.4, 0.21-0.47, 1.7-3.7, 0.55-1.6, 0.19-0.34% for N, P, K, Ca, Mg, and 24-168, 10-19, 42-138, 10-14, 9-20 mg/kg for Fe, Zn, Mn, Cu, B, respectively. DRIS indices showed that among macro and micro nutrients in all low yielding fields, Phosphorus and copper had the most negative index values, respectively. The nutritional balance index (NBI) of DRIS and of DOP (∑DOP) were much more than zero in all low-yielding fields, indicating that there was imbalance between the absorbed nutrients by sugar beet. Comparison of the DRIS method with the DOP showed that both methods provide similar information in the interpretation of the results of leaf analysis.
