الفهرس | Only 14 pages are availabe for public view |
Abstract This investigation was carried out to study the changes in so11 properties of some existing fish farms in Egypt. Three fish farms that differ in their location and structure dates were selected’, namely Al-RaswB ( Port Said), El-Wahal (Kafr El-Shaikh), and Bl- Serow (Dakahlia) Each farm was subject to various ,stages, that include leaching, flooding with water through a period of fish growth/the addition of fertilizers durin~ the rearing of fish, and the last stage was after drainage of the ponds and harveBtin~ the fish. Soil samples were taken from the 0-25 cm, 25-50 em, 50- 60 cm, and 60- 120 ca layers. !hese soil samples were physically and cheaically analyzed. Coapari ••n was carried out with the 8011 samples taken fro. the soll be:to:re :t18h ~&1’Wl1n&. The ef:tect of fish :t&rll1D& on .0:1.1 piQ’81cal and cheldcal • properties coUld be au•• eri ••• aa tellows I 1- The tiDe f’ractioDS (c1.&y aDd .n,,) 1DCreased, while the sand :trac”ion d8c”_4 ~ .oat lqera o~ profile. 2- There was no marked change in pH during the ~rowth season. However, pH values decreased with depth indicating the activity of’ anaerobic microorganisms producing CO2- 3- There was a decrease in soil salinity, however, the EO values increased with depth. 4- Soluble Be. decreased rapidly first by leaching then by flooding; Na concentration increased with depth. . - 5- Soluble K also decreased by leaching and flooding but its decrease was generally lower than Na. 6- The concentration of’ Oa at the end of study was between one to nine tenth of the original levels. A aarked decrease occurred in 11& concentration parlicularly in the upperl8\fers. 7- 1i08t of’ the chloride aalta were reaoved S DOD &:tter the 1each!.D& then lIy tlood1D&, and C1- Concentratlo: Q lDcreased .ith depth • 8- There ••.• DO _8IIUZ’<le CQ•). and in the Sa.8 tIme HCOj decreased ’7 leach±D4 1Iut increased with flood1D& parllcu1ar17 in the aurl’ace l~er. 9- 504’ decreased •• a l.”Weul t :o~ the waterloM1n& Condltlol111 in a ••• 1i1l.l”,.p. h_ftr, It lDcreased with depth. 10- The exchangeable base content (CEC) increased upon utilization of the soil as fish ponds, in most layers of the 80il profiles. 11- Although the initial leaching decreased exchangeable Na in the saline soils, there was an ultimate increases in exchangeable Na’at the end of the growing fish season, particularly were the floodin& water was saline. 12- Exch~eable K were slightly increased in some farms, and a sliBhtly decrease was occurred in the other farms. 1)- bchangeable Ca increased, in &1- ’1ahal and the two surf’ace layers of Bl- Serow farm, while it decreased in Al- Ra8Wa and the deep layers of Rl- Sera. fara. Exchan&eable Jl& increased nearly in all sites, the !Dare •••••.• aore1D the sur1’aee l”era. 14- SodiUli adsorptiDD ratio (~) and exchan«eable 80diUII percent8&e (&V),. wre lIula.1ectto decrease upon utUisat:l.oJl .t the •• U _ ~l.ah far.-. The BSP ••••.•.•• bieber at tibia .ad ot .”wi,., thi8 is excb&D&e c.pacity parlloular17 1Jl tile ”’p 1a;rera •. 15- Available phosphorus increased by flooding and fertilization. 16- Also, or&anic matter was increased in moat fish farms specially when the farms received an fresh water. |