Mention Jethro Tull to most people, and the chances are they'll think of the chart-topping rock band who emerged from Blackpool in the 1960s. This does a great injustice to their 18th-century namesake, who is highly revered in agricultural circles for his pioneering ideas and inventions.

Tull revolutionised agricultural practices in this country, and most modern machinery owes much to his influence. It is only due to the county boundary changes in 1974 that Tull sneaks into this blue plaque series, for his life was firmly rooted in Berkshire.

But Crowmarsh Gifford - where he lived for ten years, and where he invented his famous seed drill - is now part of Oxfordshire. It is here that a blue plaque was erected in September 2002, marking his former farmhouse, now 19a The Street.

Tull was undoubtedly ahead of his time. His devotion to scientific advancement foreshadowed the principles of the Enlightenment - the 18th-century Age of Reason' that advocated, among other things, the pursuit of empirical knowledge for the greater good of mankind.

He was born in Basildon, Berkshire, in 1674 (the exact date is not known) and baptised at the parish church of St Bartholomew on March 30.

His father - also Jethro - was a wealthy farmer and landowner, while his mother, Dorothy, was part of the Buckeridge dynasty that dominated the parish at the time.

In 1691, aged 17, Tull went up to St John's College, Oxford, to study law.

It is likely that he went on a Founder's Kin scholarship, for which all descendants of the Buckeridge family were entitled to apply, as they were distantly related to the college founder, Sir Thomas White. Tull left after only two years without a degree, probably due to the ill-health that dogged him throughout his life.

Despite his health problems, he qualified as a barrister in 1699, having studied first at Gray's Inn in London, and later at Staple Inn. During his time in London, Tull learned to play the organ, and became fascinated by the instrument's inner workings. He was later to apply some of its mechanical principles to his own inventions.

Tull's ambitions for a legal career were thwarted by his persistent ill-health, so he opted to follow in his father's footsteps and take up farming instead. Although this decision was undoubtedly forced upon him by circumstances, he appears to have accepted the situation with pragmatism and, later, with enthusiasm.

The year of Tull's graduation saw him undertake a four-month tour of the Continent - as was customary for young men of the time - during which time he carefully observed European farming practices.

On his return to England, he married Susannah Smith of Burton-Dassett, Warwickshire, and the couple settled at Howberry Farm, Crowmarsh Gifford. It seems to have been a happy union, and over the next few years they had five children; four girls and a boy.

From the start, Tull was keen to find ways of increasing crop production. Standard practice at the time was unsatisfactorily haphazard - farmers would simply scatter the seeds among the weeds and hope for the best.

Tull advocated a more orderly method: making straight furrows in which to plant the seeds, which could then be covered with soil, and weeded regularly. It was the reluctance of his own farmhands to try out his new ideas that led him to develop his famous horse-drawn seed drill.

Tull's seed drill, which he first used around 1701, was revolutionary in that it was the first agricultural machine to feature internal working parts. It was also fast, economical and neat, as it allowed three rows of seeds to be planted simultaneously, and combined the drilling, sowing and covering of seeds into one operation.

As a result, crop yield increased by up to eight times.