SMALL HOLDINGS 119 



small holder should not be induced to replace 

 dung by artificial fertilisers for use on poor 

 soil intended to grow leguminous crops, 

 inasmuch as bacteria are as essential as the 

 plant food the dung supplies. 



There is, however, another value in dung 

 to which reference may be made; and here 

 again we deal both with the principle of 

 manuring and the principle of cultivation. 

 We refer to its mechanical value. The success- 

 ful cultivation of heavy land depends very 

 largely upon the employment of dung, and 

 especially that containing a large quantity of 

 straw. Clay, of which heavy land is chiefly 

 composed, is a plastic material which is not 

 easily reduced and mellowed. The admixture 

 of coarse dung, however, reduces its plasticity, 

 and by its continual employment, and es- 

 pecially if it is supplemented by the use of 

 lime, sand, ashes, or the ploughing-in of green 

 crops, a loam-like condition is ultimately 

 reached. Thus the improvement of a clay 

 soil depends, apart from good cultivation, 

 almost entirely upon the introduction of 

 organic matter. 



We have seen, then, that dung possesses 

 the property — and on this point it is a 

 purely mechanical property — of improvmg 



