1768 



FORAGE CROPS, MEADOWS AND PASTURES 



oiil^" the qo per cent was used on clay land, gave better results than ammo- 

 niuin nitrate was not [completely assimilated by the plant or that it 

 was utilised for stem and leaf production to a greater extent than the am- 

 monium sulphate. 



7) The experiments show that the nature of the nitrogenous manure 

 has a very great influence upon the utilisation of potash and phosphoric 

 acid. These two substances are used to the greatest advantage in the 

 presence of ammonium sulphate, annnoniimi nitrate and cyanamide, in 

 the order named. 



8) Purin is very satisfactory, especially on clay soils, so that it 

 deserves special attention on this account. 



FORAGE CROPS, 



MEADOWS 

 AND PASTURES 



1277 - Pasture Problems: Indigenous Plants in Relation to Habitat and Sown 



Species. — vStapledon R. G. and Jenkin T. J., in Journal of Agricultural Science, 

 Vol. VIII, Part I, pp. 26-64. Cambridge, September 1916. 



The aims of the present paper are a) to trace the relationship that 

 exists between the several indigenous plants that contribute to the herbage 

 of different types of grassland : 



b) to follow the progressive changes that occur on fields (down to 

 grass for a varying number cf years,) belonging to these types ; 



c) to follow the competitive interaction between sown and indi- 

 genous species ; 



d) to contrast the effect on the herbage of continual mowing and 

 continual grazing. 



Most of the data presented are derived fioni investigations in South 

 and Mid Wales, but occasional examples are given from North Wales and 

 the Cots wolds. 



A distinction is drawn between natural and semi-natural types of 

 grassland. Natural types are those which historical evidence suggests 

 have never been extensively under the plough or manured and which, if 

 broken or manured at a remote period, have completely reverted to type. 

 Semi-natural types are those which have certainly, at one time or another' 

 been under the plough and, at all events, manured during the rotation 

 previous to reverting to grass. The semi-natural types ma}^ be further 

 classified as untended, those which have been ploughed and probably ma- 

 nured 50 to 100 years ago, and tended, those which have been down to 

 grass for 20 to 50 years. 



Grassland plants may be divided into the following classes, which 

 are applicable to all districts and to all tjq^es of grassland. 



a) Primary indigenous species, which colonise natural grassland. 



b) Secondary indigenous species, which come in without having 

 been sown and which contribute largely to the herbage on semi-natural 

 types of grassland. 



c) Tertiary indigenous species, which come in by themselves on 

 young leys but which disappear as the fields approach the semi-natural 

 type. 



d) Locally exotic species, which are indigenous to a district but 



