62 Pasture Prohlem^s 



(c) The seeds of many species are certainly introduced as impurities 

 (useful and otherwise) in the sown seeds, e.g. Phleum pratense (in 

 Trifolium hyhridiim), Plantago lanceolata (in Trifolium spp.), Holcus 

 lanatus and Bromus mollis et spp. (in Lolium spp.). 



(d) There seems little doubt, however, that the seeds of a great 

 number of species are capable of lying dormant for long periods in 

 the soil; in particular we suspect this to be true of Trifolium repens 

 and T. minus, Cynosurus cristatus, Poa spp., PJileum pratense, and 

 Festuca ovina. 



The data brought forward in this paper would seem further to 

 justify the following broad generahsations with regard to both experi- 

 mental work on grassland and the whole problem and economics of 

 putting land down to grass. 



(1) Experimental plots dealing with seeds mixtures should be 

 large (at least half an acre) and square in order to give a considerable 

 central zone. The hay should be cut as early as possible to avoid 

 seeding and the carriage of seed from plot to plot. No series of plots 

 can, henceforward, be regarded as complete without a control plot, 

 which control should not be seeded (with grasses and clovers) but left 

 to the indigenous species to colonise. The control plot should, of course, 

 be subjected to the same cultivations, receive the same manures, and 

 grow the same nurse as the seeded plots. 



(2) Undoubtedly when putting land down to long duration grass 

 as much or more can be done by making the habitat as suitable as 

 possible to the desirable indigenous species as by including their commer- 

 cial counterparts in the mixture. The commercial permanent grasses 

 are far more valuable for say 4-6 year leys than they are for permanent 

 grass as such. 



Poa spp. and Cynosurus cristatus to some extent tide a field over 

 its critical third and fourth years in proportion to the sowing, but 

 in the later years the amount of the original seeding becomes of small 

 significance compared to the influence of proper manuring and general 

 management. Speaking generally pasture conditions favour the valuable 

 indigenous species better than meadow conditions. On poor soils 

 especially we are accumulating evidence to show that rape^ (folded on 

 the land) is a much better nurse than oats or barley (removed from 

 the field). 



1 Mr Wibberley also informs us that he has got excellent results under rape on mountain 

 land in Ireland. 



