الفهرس 
Distribution of reclaimed soils in EgyptOnly 14 pages are availabe for public view
 |  | from | 202 |  |  |
| | | from | 202 | | |
Abstract
SUMMARY
This study aims to investigate the impact of the irrigation system and
the reclamation processes on the soil chemical properties, the
improvement of those properties and the crop productivity. The area of
the study lays in Upper Egypt at El Nokra district.
The irrigation system used in different sub areas were the flooding
irrigation system, Furrow, sprinkler, and drip systems. The reclamation process were similar in some steps such as surface soil plowing, laser settlement and leaching. While there were some addition differences such as the depth’s of plowing which ranged between 20 to 80 cm, the addition of different amendments such as compost, or
organic manure and mineral fertilizers such as phosphate, nitrate e.t.c.
and addition of gypsum in some locations. Irrigation water samples were collected and analyzed to check their suitability for irrigation according to the (FAO, 1979) criteria. The parameters of the irrigation water quantity of the samples collected from
main and sub main canal were coincide the standard value of the parameters of the (FAO, 1979). Soil samples were collected from different location in the studied area. The soil samples were analyzed to determine the soil texture EC, pH, soluble cations and anions, CaCo3 and nitrogen contents.
The results of soil properties indicated the following. All the soil
under study were sandy soils in addition to the existence of fine to
medium gravels in many location. The sandy soil texture increases the
soil permeability which enhanced the soil salts to be leached during the
process of reclamation. The impact of different irrigation system and differentreclamation process had a favorable affection the soil salinity where the EC values of the surface soils decreased compared to that of the soil that not cultivated or not reclaimed. The percentages of EC values decrease in values ranged between 20 %
to about 90 % of the initial soil EC.
There were no significant differences between the decrease percentages the EC values under different irrigation systems or reclamation processes which mean that the impact of leaching at the startof reclamation was the major factor for decreasing the EC values. Whilethe addition of the organic amendments or gypsum did not affect the
decrease of EC values.
The addition of gypsum to the soil under leaching with fresh
water is help in aggregating the soil particles. The impact of gypsum
addition was not clear because the soil texture is sand and the cations
exchange capacity of the sand soil is always low which means that the
addition of gypsum was not effective and not economically. The addition
of compost and organic manure sometimes increase the EC of the soil
and decrease the pH values. The decrease of pH value increase the
solubility of heave metals in soil and water. There fore organic manure or
fertilizers should be added with care to avoid any reverse impact. The
crop productivities of wheat and clover crops were different under
different treatment. The differences were not related to the values of
salinity in the soil because wheat is a tolerant crop. Also, the differences
were not affected by the irrigation system but may be attributed to the
addition of fertilizers and water soil management that practiced by the
owners of the land.
Due to the absence impact of the irrigation system on crop yields
of the different crop and the low concentrations of calcium carbonate it is preferable to use the drip irrigation system to prevent the losses of water