Relation of Plant Growth to Root Spaced 



By 

 S. Kumakiri. 



The causes of the smaller yield of plants when grown in 

 small pots compared with sneh grown in larger pots have been 

 repeatedly discussed by various authors, most recently again 

 by Lemmermann. The final conclusion at which this author 

 has arrived is that the condition of the soil nutrients, and 

 especially of the water supply are less favorable in small than 

 in large pots. It is a fact that pots kept in a glass house and 

 manured at the same rates as is usual in the fields, will yield 

 generally less harvest than fields for an equal number of plants. 

 The increased supply of nitrogen by the rain can not fully 

 explain the better growth on the fields — under otherwise equally 

 conditions. 



The roots of plants grown in small pots will run to a great 

 extent along the walls of the pots, as Sachs had already point- 

 ed out, hence they are on one side not in contact with the soil 

 from which they draw the nutrients. 



This unfavorable condition will not be so great in a large 

 pot as in a small pot under otherwise equal conditions. 



It is clear that the differences will increase with the number 

 of plants and size of the species. In order to obtain here some 

 data, the yield of a small species, spinach, was compared with 

 that of a larger, viz., barley. 



The soil serving for the experiment was a loamy humus soil 

 and was manured per 10 kilo with: 



5 g. Double superphosphate. 



6 „ NaN0 8 



I Tin article waa published also in tlie Bulletin of the College of Agriculture, 

 Tokyo Imperial University. Vol. VIII. No. :;, 1907. 



