158 Irrigation and Drainage 



of summer |allowing, as that practice is now generally 

 understood, except that it possessed one important ad- 

 vantage : namely, his strips being so narrow, and hence 

 so numerous, that both the moisture saved by the til 

 lage and the nitrates developed became available to 

 the plants growing along the margin. Further than 

 this, a part of the rain which fell upon the strips, 

 both by its lateral capillary movement and by the 

 development of roots into this unoccupied ground, 

 contributed to the growth of the crop as though it 

 had been partially irrigated, or its rainfall had been 

 increased, which in fact it had. 



The Rev. Mr. Smith, at Lois-Weedon, in North- 

 amptonshire, raised wheat very successfully by still a 

 different modification of Tull's idea. His practice 

 was to sow about one peck of seed to the acre, by 

 dropping the grains 3 inches apart in three rows 1 foot 

 apart, and leaving a space 3 feet wide unplanted be- 

 tween each group of three rows. These strips were 

 thoroughly tilled until the wheat was in bloom, and 

 kept free from weeds. He even went to the extent of 

 trenching the naked strip, bringing up some of the 

 subsoil and putting the surface loam into the trenches. 

 By his thorough tillage, thorough aeration and con- 

 servation of soil moisture, he was able to maintain a 

 yield of 18 to 20 bushels per acre without manure. 



These cases of old and now generally abandoned 

 practice are called up here because they involve a 

 principle which, when correctly applied, is of great 

 importance in sub -hum id climates, where water for 

 irrigation is not available. The principle referred to 



