تأثير المحراث تحت سطح التربة الاعتيادي و المطور و عمق الحراثة في الكثافة الظاهرية و المسامية الكلية للتربة الطينية خلال مراحل نمو محصول زهرة الشمس (Helianthus annus L.)‎

Abstract 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 .

These plow types were used to study their effect on the Bulk density and Total Porosity soil of the clay 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 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 reducal ρb and increased ƒ compared with unplowed soil (NT) .

S1D3 and S2D3 treatments gave lower ρb and higher ƒ while MT gave the highest values of ρb and lower ƒ .

ρb increased and ƒ decreased as the soil depth increased and the growth season progressed .