Sowing machine for distributing seeds on the ground, which is intended to advance on the ground along an advancing direction and comprises: - a support frame; - sowing means mounted on said support frame adapted to release the seeds on the ground in sowing positions; - at least one seed passage sensor associated with said sowing means and adapted to detect the passage of the seeds which are released on the ground in said sowing positions; - at least one advancing sensor adapted to detect the advancing of said sowing machine; - mulching means, which comprise at least one reel wound with a covering sheet and mounted on said support frame downstream with respect to said sowing means, in the advancing direction of said sowing machine, in order to extend said covering sheet on the sowed ground; - cutting means for cutting the covering sheet mounted on said support frame and adapted to make a plurality of through openings in the covering sheet; wherein - said sowing means comprise a conveyance duct, which is adapted to release the seeds from an outlet section placed at said sowing positions; said sowing machine comprising a logic control unit, which is operatively connected to said seed passage sensor, to said advancing sensor and to said cutting means and is configured for driving said cutting means to make said plurality of through openings in areas of said covering sheet intended to be extended on the ground at said sowing positions for the seeds; said sowing machine being characterized in that: - said at least one seed passage sensor being associated with the outlet section of said conveyance duct in order to detect said seeds substantially at said sowing positions thereof on the ground. - a support frame; - sowing means mounted on said support frame adapted to release the seeds on the ground in sowing positions; - at least one seed passage sensor associated with said sowing means and adapted to detect the passage of the seeds which are released on the ground in said sowing positions; - at least one advancing sensor adapted to detect the advancing of said sowing machine; - mulching means, which comprise at least one reel wound with a covering sheet and mounted on said support frame downstream with respect to said sowing means, in the advancing direction of said sowing machine, in order to extend said covering sheet on the sowed ground; - cutting means for cutting the covering sheet mounted on said support frame and adapted to make a plurality of through openings in the covering sheet; - said sowing means comprise a conveyance duct, which is adapted to release the seeds from an outlet section placed at said sowing positions; said sowing machine comprising a logic control unit, which is operatively connected to said seed passage sensor, to said advancing sensor and to said cutting means and is configured for driving said cutting means to make said plurality of through openings in areas of said covering sheet intended to be extended on the ground at said sowing positions for the seeds; said sowing machine being characterized in that: said sowing machine comprising a logic control unit, which is operatively connected to said seed passage sensor, to said advancing sensor and to said cutting means and is configured for driving said cutting means to make said plurality of through openings in areas of said covering sheet intended to be extended on the ground at said sowing positions for the seeds; said sowing machine being characterized in that: - said at least one seed passage sensor being associated with the outlet section of said conveyance duct in order to detect said seeds substantially at said sowing positions thereof on the ground.