64 PEEMANENT AND TEMPOEAEY PASTUEES. 



Poa trivialis was first cultivated about 1780, and is now 

 generally considered to be superior to Poa pratensis. On strong 

 moist soils this is doubtless true, but the favourable comparison 

 does not extend to light land liable to burn, on which the former 

 dies. The plant is rich in potash and phosphoric acid, so that 

 unless the land is good and constantly fed it soon becomes ex- 

 hausted. It is liable to injury by spring and autumn frosts, and 

 also by severe winters. 



This grass forms a large part of the natural turf of the 

 valleys in mountainous districts where the rainfall is consider- 

 able. It thrives under trees, prospers in water-meadows and 

 all moist dripping situations, and bears well the hoofs of stock, 

 but it must be mown before the foliage turns yellow at the base, 

 or it is liable to rot. Sinclair says that it is unprofitable for any 

 purpose on dry exposed situations. 



Poa trivialis flowers at the time of cutting hay, but is 

 especially useful for pastures nevertheless. The herbage is 

 of more value at the time of ripening seed than before, but 

 as ripening does not take place until the end of July, it is im- 

 possible in the South of England to keep the hay crop wait- 

 ing for it. Tlie aftermath is good after early cutting only. 

 Sinclair advises its use exclusively for permanent pastures on 

 rich soils and in sheltered positions, and I quite agree with this 

 view. 



Valuable as this grass is for such situations, I do not consider 

 that for any other land it is worth while to incur the cost of seed, 

 which, if true, is always expensive. Wherever Poa pratensis 

 will answer, it should be used instead. 



Nitrate of soda combined with mineral manures has a 

 marked efiect on the development of this grass, while, on the 

 contrary, ammonia salts diminish its growth. The Eothamstead 

 experiments have clearly estabhshed the fact that in this respect 

 it differs altogether from Poa pratensis. 



The botanical description and chemical analysis are given on 

 page 160, facing an illustration. 



