3230

3157

كارشناسي ارشد

﴿مكانيك ماشين هاي كشاورزي ﴾

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1384

چهارده، 87، [II]ص.: مصور، جدول، عكس، نمود

ص. ع. به فارسي و انگليسي

عباس همت

جهانگير محمدي، محمدرضا اخوان صراف

امين الله معصومي، محمدعلي حاج عباسي

1396/02/30

كتابنامه

كشاورزي

مهندسي كشاورزي

ID3157

به فارسي و انگليسي : قابل رويت در نسخه ديجيتالي

AbstractIn conventional tillage systems uniform depth tillage is applied over the entire the field however the depth of hardpan layer varies greatly within the field Site specific tillage which modifies physical properties of soil only where the tillage is needed for cropgrowth could achieve significant savings in tillage energy Site specific tillage can beimplemented either through a pre tillage map technology would be a two step process inwhich a sensor such as a soil cone penetrometer would be used to develop mapsshowing hardpan existence and depth This map would then be used in the site specifictillage equipment control system to control tillage implement location and depth Thereal time sensor would provide a one step system to control tillage implement locationand depth In this research a GPS based tractor mounted cone penetrometer fordeveloping geo referenced soil resistance to penetration map was constructed GPS based variable depth subsoiler was developed and evaluated On the go the controllersystem of variable depth subsoiler based on the soil compactiom map control thetillage depth The variable depth subsoiler was first calibrated in the workshop Theresponse time of the electro hydraulic actuator was measured The precision andaccuracy were 1 2 and 0 83 respectively Then the variable depth subsoiler wasevaluated under actual field conditions The time required for the implement to reach toset depth under two ground speeds 2 6 and 3 6 km h 1 was measured In the third partof this work the spatial variablility of mechanical resistance to penetration PR andgravimetric moisture MC at a depth of 0 50 and 0 40 cm respectively in a silty clayloam soil was studied Two and three dimensional PR and MC maps of one hectarefield on the 10 m 10 m and 40 m 40 m grid respectively and semivariogram modelfor 10 cm think layer were developed PR followed a spherical semivariogram model The variation of PR with soil depth showed that a hardpan layer was existed at 25 30cm Correlation between PR and MC was only significant for 0 10 cm layer Based onspatial variability of hardpan layer depth the one hectare field was divided to fourmanagement zone for variable depth tillage

عباس همت

جهانگير محمدي، محمدرضا اخوان صراف

امين الله معصومي، محمدعلي حاج عباسي