Studying the Effect of the Conventional and Modified Subsoilers on the Soil Salinity Distribution in Clay Soil during Sunflower (Helianthus annus L.) Crop Growth Stages

Abstract

A filed experiment was conducted at agriculture college research station, Garmat Ali, Basrah university in 2014. The soil texture was clay. Three plow types were used namely modified subsoiler, conventional subsoiler and moldboard plow. The first two plows (subsoilers) were used at operating depths of 30, 40 and 50 cm. The moldboard plow was used at operating depth of 25 cm . These plow types were used to study their effect on salinity distribution of the soil in middle of the season (T1) and after crop harvesting (T2). Soil properties measurements were taken for different depths, d1 (0-15), d2(15-30), d3(30-40) and d4(40-50) cm. The crop used in the experiments was sun flower (Helianthus annus L.). The following abbreviations were used for the modified and conventional subsoilers operating depths 30 , 40 , and 50 cm , which were they S1D1 , S1D2 , and S1D3 and S2D1 , S2D2 and S2D3 respectively . For the moldboard plow depth of 25 cm MT was used . The control treatment was given (NT) .The experiments were conducted using R.C.B.D. design for three replicates. The filed was divided into three equal area blocks. Each block was divided into eight experimental units. The experimental parameters were randomly distributed on experimental untis. The crop seeds were planted on 4/4/2014. The irrigation was added according to the deficiency in the water level of water evaporation basin. The addition of water was 100% of the measured evaporation value with another 20% as leaching requirement. The crop harvesting date was 4/7/2014. The results showed: The plowing operation reduced ECe, SAR and ESP compared with unplowed soil (NT). S1D3 and S2D3 treatments recorded the lowest values for ECe ,SAR and ESP while the highest values were recorded for MT. The values of these parameters increased with depth and progress of the growth season.