1906.] White and Alsike Clover Seed. 



7 



WHITE AND ALSIKE CLOVER SEED AND THEIR 



IMPURITIES. 

 Trifolium repens, white clover, is also called Dutch clover, a 

 name given because it was first collected and cultivated as a 

 seed crop in Holland and thence exported to other countries. 

 Though indigenous throughout Europe, it was not until about 

 the beginning of the eighteenth century that it was sown as a 

 field crop in this country. It differs from red and Alsike clover, 

 inasmuch as its habit of growth is low and widely creeping, but is 

 similarly provided with a well-developed tap-root, which enables 

 it to persist and hold its own during a dry scorching summer, 

 while at the same time its prostrate, creeping stems, which give off 

 adventitious rootlets at the nodes, feed mainly, if not entirely, 

 in the upper layers of soil. It may doubtless be largely owing 

 to this peculiar rooting habit that wdiite clover can withstand 

 the English climate and is very much less susceptible to climatic 

 changes than red clover. The power of accommodating itself 

 to a great variety of soils and situations may also be due to 

 the same cause. 



The roots of white clover, in common with other clovers, 

 possess an advantage over other plants in that they have the power 

 under certain conditions — even when grown in soils destitute of 

 nitrogen — of manufacturing albumenoid substances. Hellriegel 

 was the first to discover the true significance of the warts or 

 nodules on the roots of the Leguminosae, and ascertained that 

 the nodules contained innumerable nitrogen-fixing bacteria 

 engaged in manufacturing the elementary nitrogen of the air 

 into compounds, which are made use of by the host-plant in 

 building up the necessary albumenoid substance. 



White clover is found in abundance in all the best pasture 

 land in the country, helping materially, in conjunction with some 

 of the finer grasses, to form a close-bottomed grazing turf of high 

 quality; it is also considered essential and specially valuable on 

 pasture land intended for sheep grazing. In many districts we 

 can recognize two varieties growing in the fields : one, the ordinary 

 white clover of commerce, characterized by its more robust habit 

 of growth, the other a smaller-foliaged variety indigenous 

 to the soil. The seeds of the latter are occasionally offered at 

 Mark Lane as wild white clover, but as there is not apparently 



