88 The Control of the Soil [pt. ii 



hoeing or attention; {b) not systematically hoed, but 

 weeds scraped off; (c) hoed. The neglected plot becomes 

 infested with weeds and the crop does very badly, bnt 

 there is usually not much difference between the hoed 

 plot and the one where the weeds were simply pulled 

 out^. The student should try the experiment for him- 

 self. The result is very important; some of the older 

 soil workers thought that the actual stirring of the soil 

 was beneficial, but if wider experience showed that the 

 only effect was to kill weeds an important piece of know- 

 ledge would have been gained. 



Cultivated plants cannot usually survive competition ; 

 weeds therefore have to be excluded as much as possible. 

 Dr Brenchley^ has shown that the weed also suffers 

 from the competition of the crop. From the farmer's 

 point of view the most important consideration is to 

 Idll the weed : the most effective way of doing this is by 

 cultivation. The best farmers always have their land 

 cleanest, and not only do they secure bigger crops and 

 higher quality but they have nothing to waste. 



Earthing up. Some crops are greatly benefited by 

 drawing the earth up to them so as to form a ridge. 

 Potatoes in particular make better growth: special 

 implements have therefore been devised to mould them 

 up. The effect is complex : the process affords a thorough 

 hoeing, it provides more surface soil for the plant and it 

 encourages root formation. 



In China and Manchuria wheat is grown in this way. 

 The method was introduced into Europe by Demtschin- 

 sky and tested in France: it gave largely increased 



* E.g. at the Utah Agric. Expt. Station the results are aUke (Journal 

 of Agric. Research, 1917, x. 113-155): so at Illinois (Bxdleiin, No. 181). 

 2 New Phytologist, 1917, xvi. 53-76, 



