تأثير المحراث تحت سطح التربة الاعتيادي و المحور و عمق الحراثة في تماسك التربة الطينية خلال مراحل نمو محصول زهرة الشمس (Helianthus annus L.)‎

الملخص EN

A filed experiment was conducted at agriculture college research station, Garmit Ali, Basrah university in (2014) The soil texture is clay, Three plow types were used namely modifiled 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 and control treatment, These plow types were used to study their effect on the soil cohesion of the soil in first season (T1) middle of the season (T2) and after crop harvesting (T3),The 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 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 difficiency 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 The cohesion decreased for all plowing treatments compared with The control treatment (NT), modifiled subsoiler for depth 50 cm(S1D3) and conventional subsoiler for depth 50 cm (S2D3) treatments surpassed the other treatments in recording the lowest values for both parameters while The moldboard plow was used at operating depth of 25 cm( MT) recorded the highest values, The valus of the cohesion increased with depth and growth season