Process for direct drilling heavy or compacted soil comprising first killing the weeds and thereafter drilling into sub-stantially undisturbed soil; wherein the porosity of the soil is improved before drilling by making a series of adjacent substantially parallel diagonal cuts therethrough to fissure the body of the soil without substantial disturbance of the surface. Also claims a blade for carrying out such fissuring with a hinged extension on the trailing edge set at an adjustable angle to increase the soil fissuring as required according to soil type. Crumble rollers may be located between adjacent blades to provide impact blows or pressure upon the temporarily raised soil lifted up by the soil-fissuring blades. Alternatively angled cutting knives on rotating shafts may follow the fissuring blades.
