r 97 i 



the distances in each case being 18" xg", though the propor- 

 tion of increase in the latter case is larger. 



122. Drilling and Hoeing. The space allowed between 

 plants not only helps in root development and better growth, 

 but also in weeding. Sowing in drills or regular lines and 

 having & perfectly level field, one is able to do the weeding by 

 bullock- hoes, when plants are of that height (3 inches to a foot) 

 when bullock-hoes can be used without much loss by treading 

 or breaking of stems. Where stem development is considered 

 undesirable, as in the case of fibre crops, deep cultivation 

 and thick sowing are advisable. The objects of plough- 

 ing and reploughing a field, of levelling it, of sowing seed 

 in drills, and of weeding it with bullock-hoes, are evident 

 from what has been said here and in the Chapter on Physical 

 Properties of Soils. There is a further object in constantly 

 using the hoe, besides weeding. Stirring the soil helps in re- 

 moving the surface pan that is formed after rain or irrigation. 

 This prevents free access of air and the consequent weather- 

 ing of soil particles. A sugarcane or potato crop should be hoed 

 within a week after each irrigation to avoid caking of the 

 soil. So great is the benefit derived from constant stirring 

 of soil during the growth of crops that Jethro Tull a famous 

 English farmer (1680 1740) jumped to the conclusion that 

 tillage alone would serve instead of manure. Tull's principle 

 was carried out to better issue by the Revd. Mr. Smith of 

 Lois-Weedon, Northamptonshire. Operating upon a clay 

 soil, Smith produced large wheat crops. His average for 

 many years being 34 bushels in place of 16 bushels 

 which was the average yield of the locality. He used no 

 manure, but simply parcelled out his fields in strip's. 5ft. 

 wide and grew the crop in drills on alternate strips in 

 successive years. The vacant strips were spaded and 

 ploughed deeply and frequently, so that by the disintegration 

 of soil and absorption of CO 2 and combined N from the air, 

 plant food enough for the next year's crop was secured. The = 

 M 



