10 HISTORICAL INTRODUCTION. 



of plant -food be rendered in the soil. He conse- 

 quently introduced and advocated the system of horse- 

 hoe husbandry. This theory, he informs us, was sug- 

 gested to him by the custom, which he had noticed on 

 the Continent, of growing vines in rows, and hoeing the 

 intervals between these rows from time to time. The 

 excellent results which followed this mode of cultiva- 

 tion induced him to adopt it in England for his farm 

 crops. He accordingly sowed his crops in rows or 

 ridges, wide enough apart to admit of thorough tillage 

 of the intervals by ploughing as well as by hand- 

 hoeing. This he continued until the plant had reached 

 maturity. As to the exact width of the interval most 

 suitable, he made a large number of experiments. At 

 first, in the cultivation of wheat, he made this interval 

 six feet wide; but latterly he adopted an interval 

 of lesser width, that finally arrived at being between 

 four and five feet. He likewise experimented on each 

 separate ridge as to which was the best number of 

 rows of wheat to be sown, latterly adopting, as 

 most convenient, two rows at ten inches apart. The 

 great success which he met with in this system of 

 cultivation induced him to publish the results of 

 his experiments in his famous work, ' Horse-Hoeing 

 Husbandry/ 



While Tull's theory was based on principles at 

 heart thoroughly sound, he was carried away by his 

 personal success into drawing unwarrantable deduc- 

 tions. Thus he came to the conclusion that rotation 



