Effect of Irrigation Water Salinity on Some Soil Properties and Wheat Yield in Egypt

Wheat plant (Triticum aestivum, sakha-8) was grown in pot experiment to study the effect of salinity levels and salt composition of irrigation water with and without N fertilization on soil chemical properties and grain yield of wheat plant. Therefore surface soil samples of nonsaline silty clay loam soil was used. Tap water was salinized to be as natural irrigation water in the studied region using mixture of CaCl2, MgCl2 and NaCl at different ratios. Three salinity levels were prepared from different mixture to give nine type of irrigation water and tap water was used as control treatment. Soil salinity after plant harvesting increased with increasing water salinity up to 12.70 dS/m compared with it before planting (2.23 dS/m) or after harvesting using irrigation with good water (2-79dS/m).On the other side, soil reaction (pH) decreased from 8.17 to 7.65 with increasing water salinity. Values of sodium adsorption ratio (SAR) for soil solution also increased from 3.65 up to 11.24 and soil exchangeable sodium percentage (ESP) was correlated with soil SAR, where it increased from 4.24 to 11.91%. Soil content of available N and P almost decreased with increasing water salinity after plant harvesting. The results indicated that the grain yield was significantly decreased either with increasing salinity levels or Na concentration in irrigation water used. This effect was decreased with added-N, where grain yield was increased by about 2 to 3 fold compared with it without N fertilization under this conditions. Grain content of Na was increased to give less quality of grain yield. Plant uptake of Na decreased with increasing levels of added –N

Phosphorus Loss into Ground Water in Paddy Soils as Influenced by Irrigation System and Rate of Added-P

A field experiment was carried out in delta Nile region of Egypt, to elucidate the impact of irrigation system and graded phosphorus fertilizer rates on P loss into ground water in paddy soils (heavy clay soil). Three irrigation system were used: submergence with continuous head of water (about 8 cm), irrigation with saturation percent and discontinous irrigation where soil was irrigated every 7 days. The rate of applied P were 45 and 90 Kg P2O5/acre as super phosphate. Values of dissolved reactive phosphorus (DRP) in ground water increased under saturation and discontinuous irrigation compared to it under submergence condition (e.g.,0.25,0.18 and 0.14 mg P/L, respectively) under 90 Kg P2O5 /ac. and after 15 days of added-P. Accumulation values of DRP in ground water after 105 days at 90 Kg P2O5 /ac. of added-P were 1.18,0.76 and 0.67 mg P/L under saturation, discontinuous and submergence irrigation methods, respectively. The rate of loss for DRP in ground water was the highest under saturation method at 90 Kg P2O5 /ac. ( 0.01 mg P/L/day). Results also showed that, accumulated total phosphorus (TP) at the end of ground water collection (105 days after transplanting) when 90 Kg P2O5 /ac. was added were 2.78,2.18 and 1.69 mg P/L under discontinuous, saturation and submergence irrigation system, respectively. Also, the rate of loss for TP was the highest under discontinuous irrigation condition (0.025 mg P/L). These results indicated that, increasing added phosphorus fertilizer let to increasing P loss into ground water by leaching through the soil profile.In addition, phosphorus loss into ground water was increased with decreasing added water for irrigation in paddy soils (increasing drought regime) and that was not expected

Quantitative Relations of added N fertilizer and soil–N for wheat plants irrigated with different saline water in Egypt,

A factorial greenhouse pot experiment was carried out at Fac. Agric. Kaferelsheikh,Egypt in winter season to investigate theefficiencies and quantitative relations of the added N fertilizer (0, 30, 60 and 90 kg N/acre) and soil – N on wheat yield wheat crop was irrigated with tap water (Wo) and three artificial saline water(W1,W2 and W3) with three levels of salinity(C1,C2 and C3)for every one. All treatments were replicated three times. The results can be summarized as following: - The calculated grain yield when no fertilizer added, was decreased when salinity levels and sodicity of irrigation water increased . - The maximum yield was decreased when salinity level of irrigation water increased. - The maximum addition of N fertilizer decreased due to increasing salinity and sodicity of irrigation water. - The useful of soil – N was decreased when salinity level of irrigation water increased and also with the type of irrigation water according to the following order: W0 > W1> W2 >W3. - The efficiency of added – N fertilizer decreased when added N levels increased while this efficiency increased as salinity levels of irrigation water increased. - The contribution of N – fertilizer in yield production was increased when salinity levels of irrigation water increased. On the other hand, the contribution of soil - N was decreased when salinity and added N increased. As the fraction of added Nfertilizer increased the fraction of soil - N decreased with the same ratio

Purification, characterization, and cloning of a bifunctional molybdoenzyme with hydratase and alcohol dehydrogenase activity

A bifunctional hydratase/alcohol dehydrogenase was isolated from the cyclohexanol degrading bacterium Alicycliphilus denitrificans DSMZ 14773. The enzyme catalyzes the addition of water to α,β-unsaturated carbonyl compounds and the subsequent alcohol oxidation. The purified enzyme showed three subunits in SDS gel, and the gene sequence revealed that this enzyme belongs to the molybdopterin binding oxidoreductase family containing molybdopterins, FAD, and iron-sulfur clusters

Monitoring of microbial hydrocarbon remediation in the soil

Bioremediation of hydrocarbon pollutants is advantageous owing to the cost-effectiveness of the technology and the ubiquity of hydrocarbon-degrading microorganisms in the soil. Soil microbial diversity is affected by hydrocarbon perturbation, thus selective enrichment of hydrocarbon utilizers occurs. Hydrocarbons interact with the soil matrix and soil microorganisms determining the fate of the contaminants relative to their chemical nature and microbial degradative capabilities, respectively. Provided the polluted soil has requisite values for environmental factors that influence microbial activities and there are no inhibitors of microbial metabolism, there is a good chance that there will be a viable and active population of hydrocarbon-utilizing microorganisms in the soil. Microbial methods for monitoring bioremediation of hydrocarbons include chemical, biochemical and microbiological molecular indices that measure rates of microbial activities to show that in the end the target goal of pollutant reduction to a safe and permissible level has been achieved. Enumeration and characterization of hydrocarbon degraders, use of micro titer plate-based most probable number technique, community level physiological profiling, phospholipid fatty acid analysis, 16S rRNA- and other nucleic acid-based molecular fingerprinting techniques, metagenomics, microarray analysis, respirometry and gas chromatography are some of the methods employed in bio-monitoring of hydrocarbon remediation as presented in this review