The advantages of these deep-rooting plants are hardly appreciated 

 by the farmer who has not made a test of their worth. They improve 

 the texture of the soil, permitting water to be more freely absorbed; 

 they, in a measure, admit air, and when they decay, the organic matter 

 is resolved into humus which, acting with the air and water, combines 

 with inorganic plant food elements, making them available. Plant 

 food thus formed is brought to the seed-bed or the upper subsoils by 

 capillary attraction and utilized by other plants. This process accounts, 

 to a great extent, for the increase in any crop that follows clover or 

 alfalfa. 



The legumes are further beneficial in this, that they have the power 

 through a bacteria which forms on the roots to take nitrogen from the 

 air, not only in sufficient quantities to provide for their own wants, but 

 to deposit a considerable amount in the stubble and roots, which 

 becomes a part of the soil. 



Storer says that for every ton of clover hay harvested, 1600 pounds of 

 roots and stubble are left upon the land. 



Heiden states that of the total nitrogen produced by a clover crop 

 (roots included), 58 per cent are contained in the stalks and leaves above 

 the ground and 42 per cent in the roots. In proof of the fertilizing 

 power of clover-refuse, Boussingault states that wheat taken before 

 clover in the rotation studied by him habitually gave 16 or 17 hecto- 

 litres of grain to the hectare, while wheat taken after clover, gave 20 to 

 21 hectolitres. It also appears from results obtained by Voelcker that 

 clover roots and stubble after the second cutting for hay contained less 

 nitrogen than the stubble and roots after the first cutting for hay and 

 the second cutting for seed, as is shown in the following table: 



The difficulty in securing a stand of clover and the possibility of 

 winter-killing prevents many farmers from growing it. Failures, how- 

 ever, to secure a stand is due very often to a poorly-made seed-bed. 



67 



