The present invention concerns the agricultural sector.In particular, the invention concerns a sub-irrigation method for crops sown in rows, comprising the steps of:- laying, below agricultural soil (1), parallel to one another and at a regular pitch (P), a plurality of perforated pipes (2) for the underground distribution of water- sowing seeds (3) in parallel rows in said agricultural soil (1)- feeding water into said perforated pipes (2)characterised in that said step of laying, below agricultural soil (1), a plurality of perforated pipes (2) parallel to one another and at a regular pitch (P) for the underground distribution of water, comprises the step of storing the position of said perforated pipes (2) and in that said step of sowing the seeds (3) in parallel rows comprises the prior step of identifying the position of said pipes (2) and the subsequent step of sowing the seeds (3) over said pipes, maintaining the same regular pitch (P), so that the water distributed by sub-irrigation reaches the roots of plants (4) that have grown from said seeds (3) without totally saturating the agricultural soil (1) between said pipes (2).
