Plants would grow better, he said, if the soil was thoroughly broken down, not only during sowing but in the early stages of growth. For this purpose he invented two machines, the seed-drill and the horse-hoe. With these, crops could be sown in drills or rows sufficiently wide apart so that the horse, drawing the hoe, could walk without damage to the plants, and provide tillage with the hoe during almost the whole period of growth. This after-cultivation of the growing plant was the centre point of Tull’s thinking, and the practice of course is carried on to this day. His horse-hoe was just an adapted wooden plough.
In 1711 Tull went on an extended visit to the Continent to study methods of agriculture in France and Italy. He returned in 1714 and it was not until 1731 that he published his famous book Horse-Hoeing Husbandry.
But, although Tull is reckoned as the greatest original thinker about farming processes which England had then produced, his theories fell upon stony ground. Very few eighteenth-century farmers were prepared to listen to his wisdom. Most of them clung to the old ways, and it was a hundred years before Tull’s methods began to be generally applied.