E. A. Elamin

Phosphorus and Potassium Fertilization Effects on Growth Attributes and Yield of Two Sugarcane Varieties Grown on Three Soil Series

Abstract A two-year field trial was carried out in the seasons of 1997/98 and 1998/99 at Sennar Sugar Company (latitude 13° 33′N and longitude 33° 37′E), to investigate the effect of different levels of potassium (0, 72, and 144 kg K/ha) as K2O and phosphorus (0, 29 and 58 kg P/ha) as P2O5 on the performance of two sugarcane (Saccharum officinarum) varieties (Co 6806, Co 527) and their first ratoon grown on three soil series (Hagu, Nasr, and Dinder). The layout was a randomized complete block design arrangement using three replications. The results indicated that potassium application affected plant density and stalk diameter significantly. The stalk height of the plant cane and its first ratoon was positively affected only late in the season. In the ratoon, the effect was significant early in the season on all growth parameters. The yields of cane and sugar on Dinder series were raised significantly in response to potassium addition in plant cane and ratoon. Potassium increased yield of cane and sugar on Nasr soil and yield of sugar on Hagu soil significantly. Phosphorus addition, on the other hand, reflected a significant effect on stalk height, number of internodes and plant density of plant cane and ratoon early in the season. However, the increase in stalk height and plant density of ratoon continued as the season proceeded. In plant cane, phosphorus application significantly affected sugar yield on Hagu soil. Application of phosphorus to ratoon grown on Dinder and Hagu series resulted in significant increase of cane and sugar yields. Variety Co 6806 gave the best growth and yield compared with Co 527. Soil analysis revealed a depletion of extractable potassium after plant cane harvest. The reverse was true after ratoon harvest from Nasr and Hagu soil series. Soil available phosphorus decreased after cane cropping and increased after ratoon harvest, but both were mostly less than the initial amount before cane planting.

Alternate Use of Good and Saline Irrigation Water (1:1) on the Performance of Tomato Cultivar

Abstract A pot experiment was set in a completely randomized design with factorial arrangement using tomato (Lycopersicon esculentum cv “Tatto”) to examine the effect of cyclic irrigation with good and saline waters and mineral fertilization on yield and mineral constituents. The experiment consisted of two irrigation practices (W1 and W2) and two levels of phosphorus (P1 and P2) equivalent to 350 and 470 kg superphosphate/ha, respectively, added at the beginning of the experiment. The nitrogen (N) levels were 0, 800, and 1600 kg urea/ha, respectively, split into six doses. A basal dose of potassium (K) was added at the rate of 350 kg K2SO4/ha. One healthy seedling of tomato was transplanted three weeks after germination to each pot (0.07 m2) filled with soil classified as Torrifluvents. The treatments were replicated thrice and the pots were put in an open area at the Rumais Research Station facility. The quantity of irrigation water applied was approximated according to the data available at Rumais station. Similar quantities of good and saline waters were applied alternately to all treatments. The water-stress treatment (cyclic irrigation) started 15 d from transplanting. Yield, total soluble solids (TSS), and mineral constituents were determined. The results indicated that alternate irrigation reduced yield, but the differences between the water treatments were not significant. Nitrogen application showed a significant linear response in tomato fruit yield, and the interaction between treatments was not significant. It was also revealed that the differences between the P treatments were significant, with P2 (470 kg/ha) giving lower yields. Cyclic irrigation and mineral fertilization increased significantly the TSS. Nitrogen application at the rate of 800 kg/ha (N2) gave the highest TSS in the two water treatments at a P application rate of 470 kg/ha (P2). On the other hand, increasing the nitrogen (N) application rate to 1600 kg/ha (N4) reduced the total soluble solids in the presence of P in the two water treatments.

Variability and Correlation between Exchangeable Sodium Percentage and Sodium Adsorption Ratio in Vertisols of Sudan

Vertisols in the Sudan occur under different climatic zones, ranging from arid in the north to tropical monsoon in the south, with rainfall varying from 150 mm to 1000 mm per annum. In this study, the exchangeable sodium percentage (ESP) was estimated from the sodium adsorption ratio (SAR); values of SAR and ESP for all identified soil series of Vertisols in the Sudan were extracted from the available data. These data were used to examine the variability in SAR and ESP in these soils using coefficient of variation (CV) as an index and then to regress ESP on SAR for the three master horizons (A, AC, C) and pooled data for all horizon. Curvilinear, linear, quadratic, and cubic equations were used to examine the relation between ESP and SAR. The significance of the F ratio and correlation coefficient was tested for individual equation. The soil series were then sorted out into saline and nonsaline, sodic and nonsodic, and the ESP was regressed on SAR once again. The equations used for the regression were curvilinear and first‐, second‐, and third‐degree polynomial equations. Then analysis of variance (ANOVA) was used to screen any significant difference between the estimated values of ESP (using these equations and USDA salinity laboratory equation) on one hand and the actual (measured) values of ESP. The results revealed that ESP and SAR are highly variable irrespective of depth despite slight decrease with depth. Furthermore, ESP is more variable than SAR in horizons A and AC but less variable in horizon C. The regression equations indicated that ESP might be reasonably estimated from SAR. However, different equations were appropriate for different horizons. Moreover, the result indicated that in most of the cases the relation between ESP and SAR better fits quadratic equations. But for simplicity, linear equations for all horizons could be used to estimate ESP from SAR.

Influence of induced salinity and sodicity on manganese sorption in vertisols and aridisols

Abstract Salinity and sodicity effects on manganese (Mn) sorption in a mixed sodium‐calcium (Na‐Ca) soil system were studied. Soil samples were taken at 0–30 cm depth from Vertisols (El‐Hosh and El‐Suleimi) and Aridisols (El‐Laota) at three sites in Gezira scheme (Sudan). No Mn was applied to these soils. Prior to analysis the soils were equilibrated with NaCl‐CaCL2 mixed salt solutions to attain SAR values at different salt concentrations. The results indicated that saline soils sorbed less Mn and had higher equilibrium Mn concentrations. Sodic soils retained more Mn but had low equilibrium concentrations. Sodicity had a pronounced effect only on increasing Mn retention at higher SAR values. Salinity tended to alleviate sodicity effects on Mn retention, but soluble salts that increased soil pH decreased Mn concentration.

Salinity and sodicity effects on boron Retention by three arid‐zone soils

Abstract The effects of salt concentration (C) and sodicity, as measured by the sodium adsorption ratio (SAR), on boron retention by three arid‐zone smectic soil samples were studied. The samples were previously equilibrated with NaCl‐CaCl2 mixed salt solutions of different SAR to attain specific SAR values. Boron (B) retention generally decreased with decreasing pH and increasing C as the latter was accompanied with significant decrease in pH. When the pH was kept nearly constant, B retention slightly increased with increasing C. Sodicity generally tended to enhance the salt effect, but it had a significantly negative effect on B retention only at the highest SAR value used in this experiment.

Mobility of total petroleum hydrocarbons in Shambat soil in Sudan

Purpose – A laboratory experiment was conducted in the soil laboratory in the Department of Environment and Environmental Pollution, Environment and Natural Resources Research Institute, National Centre for Research. The purpose of this paper is to study the movement of crude oil through soil column. Design/methodology/approach – Polyvinyl chloride columns were filled with Shambat soil, amended with three concentrations of light crude oil (0.16, 0.32, and 1.28 ppm), obtained from Petrodar Oil Company. Soil samples were taken from 5 and 10 cm depths after two, 14 and 28 days from crude oil addition. At each sampling date, the recovery of petroleum hydrocarbons measured. Findings – The results obtained indicated that high by significant differences among the different concentrations, different depths and different sampling durations. Moreover, the downward mobility of petroleum hydrocarbons decreased with increasing crude oil concentration. Originality/value – Results of the experiment revealed the importan...

Combined Effects on Nitrogen Fertilization and Soil of CaCO3 Contents on Corn Performance in Al-Marj Soil, Libya

Abstract A two-year field trial was conducted at Al-Marj Research Center, northeast Libya, during the summers of 1996 and 1997 to examine the effect of nitrogen (N) fertilizers on corn (Zea mays L.) growth in a Libyan soil (fine mixed thermic, Typic Haploxerolls) amended with different calcium carbonate (CaCO3) levels. Two N fertilizer sources (urea and diammonium phosphate, or DAP) were used at three application rates (0, 80, and 160 kg N/ha). The CaCO3 treatments were 1%, 6%, and 12% based on the soil weight of a 15 cm furrow slice. A basal phosphorus (P) dose of 46 kg P2O5/ha as triple superphosphate was applied to all experimental plots before planting. The experimental plots were arranged in a randomized split-split plot design with three replications. The parameters measured included corn grain weight, plant dry-matter content, leaf contents of N, P, potassium (K), calcium (Ca), and magnesium (Mg). The plant dry matter and corn-grain yield were significantly decreased by CaCO3, but were significantly increased by N fertilizer rates. Average grain yield dropped from 8 to 3 Mg/ha at 1% and 12% soil CaCO3 content, respectively. Generally, the N source did not have a significant effect on dry matter or on grain yield. The negative effect of CaCO3 on yield was associated with concomitant significant reduction in leaf N, P, K, and Mg contents, and an increase in Ca content. However, the leaf levels of these nutrients were considered sufficient for corn growth. Therefore, the reduction of leaf-N by CaCO3 in fertilized soils might have been the major cause of corn dry-matter and grain-yield reductions.