134 Depth of Sowing Grass and Clover Seeds. [May, 



surface seedlings were invariably weak and much etiolated during 

 the early stages and were very irregular in the time taken to 

 reach the surface ; some took over five weeks to break through. 



Behaviour of Seedlings from Surface Sowings. — Under suit- 

 able conditions as regards moisture the slender rootlets assisted 

 by the long root hairs, had no difficulty in becoming fixed to 

 the soil, but when germination was immediately followed by a 

 spell of dry weather a large number of the seedlings failed to 

 become established because the exposed cells of the root hairs 

 were killed. This was clearly demonstrated by the two surface 

 sowings in the bed experiment. The " a " bed was sown on 

 16th August ; on the 17th and 18th it rained heavily while the 

 next two days were warm and dull. The conditions were thus 

 conducive to rapid germination; but on the 21st a dry spell set 

 in. which lasted 13 days with only a short break of a few hours' 

 rain on the 23rd. As a result only 16 per cent, of the seedlings 

 became established. On the other hand the germination of the 

 seeds of k " 1) plot, which were not sown until the 20th, was 

 delayed until 2nd September when a long period of wet 

 weather set in, with the result that 57 per cent, of the seedlings 

 on this bed became fixed. 



Behaviour of Seedlings when Buried too Deeply. — The rye 

 grass seedlings are able by virtue of the pointed apices of the 

 sheaths and first leaves to force their way up through the soil 

 with greater ease than the clover seedlings, but when buried 

 too deeply the food supply contained in the caryopses is 

 ^exhausted before the surface is reached. 



Conclusions. — (I) Rye Grass seeds should not be sown on the 

 surface except during a long, unbroken spell of wet weather. 



(2) Good results w T ere given when the seeds were covered 

 from J in. to 1 in. In a normal year it would probably be safer, 

 however, to cover the seeds to a depth of J in. to 1 in. 



C3) Only poor " take " can be expected when seeds are sown 

 at depths of 2 in. or 3 in. and over. 



Cocksfoot. — For reasons described when dealing with rye- 

 grass, cocksfoot gave poor stands when the seeds w T ere merely 

 sown on the surface. The number of surface seedlings (51 per 

 cent.'* was fairly high at the time of counting, but the very low 

 yield obtained from the surface beds — only 43 per cent, of the 

 weight given by J in. depth — suggests that the weak seedlings 

 must have suffered very heavy winter casualties. 



If a comparison of the percentage number of surface seedlings 

 given by the different depths is made (see the Table) it will 



