Effect of irrigation water quality in the infiltration rate of different soil textures

Abstract

A field experiment was conducted in Diyala province to study the influence of irrigation water quality and soil texture in field water's infiltration. The treatments of study were three different textures namely, first texture was loamy sand soil, second texture was loamy clay and third texture was silty clay, five different saline water were used (0.76, 4.00, 8.00, 12.00 and 16.00) dS.m-1.Also, three equations were used for conformity measures which were ( Kostiakov ( 1932) , Kostiakov – Philip , and Philip (1957d )) by using the statistical system ( SPSS ) was used to estimate equations factors, standard error and regression coefficient. Double ring infiltrometer was used to measure field infiltration value (infiltration rate and cumulative infiltration ) . The design of experiment was factorial experiment with use of Randomized Complete Block Design ( RCBD ) with three repetitions. was The result shoed that soil texture had an effect on infiltration rate and cumulative infiltration , they were increased in the loamy sand soil comparative with other two soils .The increasing percentage was 93% , 79% respectively as compared with silty clay soil which give the lowest rate. The irrigation water quality effect on filtration water when the increasing of water salinity makethe soil structure better. The increasing percent in infiltration rate and cumulative infiltration rate was 20% and 41 % respectively in salinity water treatment of 16 dS-1 compare with salinity water treatment 0.76 dS-1 while the lowest percent infiltration rate and cumulative infiltration rate in salinity water of treatment 4 dS-1 with low percent 10% , 9 % respectively compare with salinity water of treatment 0.76 dS-1.Kostiakov- Philip gave the best accordance between the infiltration values that measured in field and counted in the equations followed by Kostiakov ( 1932 ) and Philip(1957d) and for all the soils studied.