Old System of Intertillage 157 



water, and one which is great enough to modify the water con- 

 tent of the soil throughout the whole of the following season under 

 crop. The table shows that where oats were grown, the soil, 

 when the crop had been harvested, contained 8.21 pounds of 

 water per square foot, or 1.57 inches more than did the ground 

 which had not been summer fallowed the year before. The same 

 difference also existed on the barley ground, and in both cases 

 notwithstanding the fact that larger yields of both straw and 

 grain had been produced on the fallow ground. 



7. The Old System of Intertillage 



The old system of horse -hoeing, introduced by 

 Jethro Tull in England, and modified by Hunter, and 

 still later by Smith, at Lois-Weedon, has much to rec- 

 ommend it on fertile soils, in which there is a deficiency 

 of soil moisture, as is the case in the sub -humid 

 regions of this country. Tull was a close observer, 

 and early learned to appreciate the great advantage 

 of thorough tillage, not only in conserving soil mois- 

 ture, but also in developing available plant -food. He 

 strongly advocated planting in drills, so as to admit 

 of thorough and frequent stirring of the soil and with 

 the aid of the horse. 



Hunter modified TulPs system by laying out his 

 fields in strips about 9 feet wide, every other one of 

 which was sown, while the intermediate ones were 

 left naked, and were frequently cultivated through the 

 season, and kept free from weeds. In the fall of the 

 year the bare strips were sown, and the others, which 

 had borne the crop, were plowed up and tilled in a 

 similar manner. His method amounted to a system 



