الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
The study aims to investigate the effect of the northern lakes of Delta such as Edko lake on some chemical and physical properties of soils and also to assess soil properties in the light of their location in relation to the lake as well as qualities of
irrigation water .
The area of study was located at the north of Delta at Edko lake , El-Behera governorate. Fifteen soil profiles along three transects in the study area from east to west were made taking into consideration the distance from Edko lake , and each transect consisted of five soil profiles.
Transect I lies near the lake ; transect II was away from it by ten Kelometers to the south ; transect III was about ten Kelometers south of transect II
Soil of transect I were irrigated with water with mixing ratio 70% drainage water, while , soil of the second transect was irrigated with water of 30 % of drainage water. Soils of the third transect were irrigated with water which included no drainage water.
Undisturbed soil samples were collected for physical studies, while disturbed soil samples were used for the determination of some other soil physical and chemicalproperties associated to this study, In all soil profiles the soil samples were taken from 3 layers 0-30 ; 30-60 and 60-90 cm , respectively.
The obtained results revealed the following :-
•The pH values of soil. under consideration are not markedly affected by distance from the lake.
•The salts accumulation in soils was closely related to the salt soil location decreasing with increasing the distance from the lake.
Generally , there is a marked increase in the soil salinity due to use of relatively lower water quality for irrigation, especially in the case of mixing ratio with 70 % drainage water at the transect I , which is near the Edko lake.
•Soluble Na’ in soils was the dominant soluble cation followed by Mg” , CC and IC and it tended to decrease with distance from the lake . Soluble Cl* was the dominant soluble anion followed by Sal, then by soluble HCO3 which nearly constant
•The SAR values of the soils under investigation revealed that except for the high values of the transect I which lies nearest to the lake (10 to 38 and mean value of 20) values for two other transects were not very high ; (transects II : 2 to 20 with mean of 11; transect III :3 to 16 with mean of 9)•*All soil profiles under investigation are characterized by high values of cations exchange capacity. In the soils irrigated with, low quality of irrigation water , the distribution of exchangeable cations depends on the location of soil profiles beside the ratio of drainage water addition The exchangeable sodium and magnesiurh were generally dominant.
•Clay fraction represents the major content for all soils under study and range of mean values was between 57.0 ,and 69.8 the realatively lower values of clay content are found in the soil profiles of trangetetVilikeh is thtnearest to Edku lake shore
•The organic matter content is generally low and range of mean values of profiles was between 0.36 % and 2.60 %. The highest mean value was that of transect Ill.
•The cobonate content is generally high in all soil profiles of transect I compared with the carbonate content values of transect 11 and transect III
•The data of aggregate state of the investigated soils reveal that the amount of total stable aggregate is greater in the soil profiles of the transect Ill than that of transect I . The statistical data indicate that there are significant positive correlation between total stable aggregate and each of cation exchange capacity, exchangeable calcium , exchangeable magnesium , clay content and organic matter content. Asignificant negative correlation is obtained between the total
stable aggregates and each of soil salinity , soluble sodium , SAR , exchangeable sodium , silt content and CaCO3 content,
•The mean weight diameter is affected by the same soil properties the affect the aggregate state. The mean weight diameter values are high in the soil profiles of transect Ill which are under irgation with high quality water, medium values occurred profiles of transect II which are irrigated with medium quality water .
Results of aggregate size distribution as a percent of total stable aggregates show that the coarse aggregates values are 23 % , 34 % and 40 % of total stable aggregates for the transect I , II and III , respectively . In relation to the quality of irrigation water the percant of coarse aggregates are relatively high profiles of transect III ,which are irrigated with good quality irrigation water and relatively low values for profiles of transect I which received low quality of irrigation water There was a positive corelation between the coarse aggregate and each of clay , and organic matter . and exchangeable Mgnesium.
•On the other hand , there was a significant negative con•elation with each of silt , CaCO3 , soil salinity , solublesodium and soluble magnesium , SAR and exchangeable sodium.
•Proprtion of fine aggregates (0.25-0.063mm diameter) size group increases with increasing the soil salinity , soluble sodium and magnesium , exchangeable sodium and carbonate content.
•The total porosity exhibit relatively higher values in the heavier soil of transect III than in transect II or transect I
•The data of pore size distribution show that the little variation for volume rlrainable pores and fine capillary pores through the soil profiles at different locations On the whet hand the data of water holding pores show relatively increase through the soil profiles at different locations.
•The statistical relationships between the different pore size distribution and soil components indicate some non significant , postive and negative correlations.
•The highest value of available water capacity as well as field capacity are achieved by the sod profiles of the transect Ill. In relation to the different soil :properties , both field capacity and wilting point are positvely correlated with soil salinity, exchangeable calcium and exchangeable magnesium , high values of available water were associated with low values of soil salinity , exchangeable sodium , silt content and CaCO . The opposite trend is achieved with highest valuesof cation exchange capacity , exchangeable calcium and exchangeable magnesium , clay content and organic matter content.