Nov. 1896.] BOTANICAL SOCIETY OF EDINBURGH 13 



Moreover, there were some curious facts known to 

 agriculturists that could scarcely be explained in any other 

 way. 



It was well known, from the time of the Eoraans, that 

 when leguminous plants were grown on land under 

 rotational cultivation, an abundant crop of that kind was 

 followed the next season by a good cereal crop. They 

 were of opinion that the leguminous crop enriched the 

 soil. 



Farmers in this country, too, have known for ages that 

 a good crop of wheat was certain if a good crop of clover 

 had preceded it. Now chemical analysis shows us that the 

 clover crop is very rich in nitrogenous matter; and if we 

 assume that this nitrogenous matter comes to the crop from 

 the soil, it stands to reason that the removal of a clover 

 crop should leave the soil poorer in nitrogenous matter than 

 before. Such, however, is not the case. Chemical analysis 

 shows that the soil is richer in nitrogenous matter after the 

 clover crop has been carried away; so that either the roots 

 of the clover left in the ground must have got their 

 nitrogen from deep down in the ground, or it must have 

 come to the plant from the air and have been stored up to 

 some extent in the roots. 



Another common observation was that when a crop of 

 maslum was grown, which is a mixture of beans and oats, 

 or when tares and oats are grown together, the oat plants are 

 stronger and taller than those on any part of the field 

 where the oats have grown separately. So also it is 

 commonly observed that in pastures the places where 

 clover is most abundant are the places where the grasses 

 are growing greenest. 



A very striking example of the power of leguminous 

 plants to enrich the soil in nitrogen was furnished by Mr. 

 Schultz, a farmer who owned the farm of Lupitz, in Altmark, 

 X. Germany. The soil was little better than sand when 

 he came into possession of it, and he could not afford to 

 buy nitrogenous manures to bury in it, neither did he feed 

 cattle to provide farmyard manure for it. He adopted the 

 system of green manuring. He grew leguminous crops, 

 chiefly lupines, and ploughed them in, and he manured 

 his land with potash and phosphates, following Liebig'& 



