IMPKOVED STRAINS OF GRASSES 67 



which belonged to him as the village schoolmaster of Jftrslev. 

 This was the first Experimental Station of the State. On his 

 small-holding at 0rslev P. Nielsen had evolved a system of 

 field culture distinct from the Rothamsted system, which had 

 been adopted at the Royal Agricultural College, Copenhagen. 

 While at Rothamsted field experiments were carried out on 

 whole fields or on plots sufficiently large to secure a uniform 

 result, P. Nielsen introduced the system of small " parallel 

 plots " systematically distributed on the field, all of the same 

 size, not separated by path-ways, but surrounded by screening 

 belts of the same crops. By securing the greatest possible 

 uniformity of soil, method of cultivation, manuring, and so on, 

 and by repeating his experiments during a series of years, ho 

 obtained reliable results. His system has since been followed 

 on the official Experimental Stations of the Danish State, and 

 has been adopted in many other countries. How the Com- 

 parative Cultivations of roots are carried out according to his 

 system has been described in a preceding chapter (pp. 36 

 to 40). P. Nielsen died in 1897. 



His investigations on the rotation grass fields caused a 

 demand for seed of several kinds of grasses and luguminosae 

 not hitherto used to any extent. He initiated a long series of 

 experimental cultivations of these plants from seed from various 

 places abroad in order to test their relative yield ; and numerous 

 reports from the directors of the Experimental Stations appeared 

 in the official journal, Tidsskrift for Planteavl. By these reports 

 and by short communications to the weekly agricultural papers, 

 often with illustrations, farmers and seed merchants were taught 

 where the seed could be bought which would yield the greatest 

 crop when grown in Denmark. Sometimes seed of red clover 

 was bought from Italy or France, where it was cheap, although 

 seed from those countries often yielded very unsatisfactory 

 crops, the plants being unable to withstand the Danish winter. 

 P. Nielsen proved that seed of red clover from Russia, Silesia, 

 or Bohemia would yield several times more than seed from 

 Italy. Similarly with the other kinds of seed used in the grass 

 fields. 



One result of P. Nielsen's work soon appeared in the statistics 

 of the trade in seed, which showed that the amount of seed 



