The effect of the conventional and modified subsoilers on the Moisture content in clay soil during sun flower crop growth stages (Helianthus annus L.)

Abstract

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 . These plow types were used to study their effect on the Moisture content of the soil in first of the 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 following abbrivations are used for the modified and conventional subsoilers operating depths 30 , 40 , and 50 cm , which are they S1D1 , S1D2 , and S1D3 and S2D1 , S2D2 and S2D3 respectively . For the moldboard plow depth of 25 cm MT is used . The control treatment is 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 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 plowing operation significantly readused Pw compared with unplowed soil (NT) . S1D3 gave lower values of Pw while treatments S2D1 and MT gave the highest values of Pw . The operating depth (40) surpassed the other operating depth in giving higher Pw . The planting increased Pw at the middle of the season while Pw decreased at the end of the season .