1922.] Depth of Sowing Grass and Clover Seeds. 



L87 



seeds sown were able to penetrate through the Boil, while at 

 2 in. and 3 in. depths no seedlings were able to reach the 

 surface. 



In an experiment similar to that referred to when discussing 

 meadow foxtail, in which the seeds were sown weekly from May 

 to August on the surface, and at a very shallow depth, the 

 surface sowings gave the best stands when these sowings were 

 followed by fairly long periods of wet weather; when, however, 

 the germination was interrupted by a spell of fine weather, the 

 best results were obtained from the lightly covered seeds. The 

 germination of many of the surface sown seeds is often delayed 

 for a period of 6 weeks of more, even under normal conditions 

 as regards moisture. On the other hand, shade and excessive 

 moisture are conducive to a good " take," as shown by the 

 following figures given by pot cultures (surface sown) : — 



Shaded. Exposed to light. 



Surface seedlings ... ... 61 per cent. ... 49 per cent. 



That the lower percentage given by the " exposed to light " 



pots was due rather to the drier condition of the surface soil of 



these pots than to the influence of light as such is suggested by 



the following : — 



Excessive watering. Normal watering. 

 Surface seedlings .. ... GB per cent. ... 57 per cent. 



Time of Sowing. — The June and July sowings produced 

 superior stands to the May and August sowings in the weekly 

 sowing experiment already referred to. 



Conclusions. — (1) If sown under a nurse crop or during wet 

 weather it would probably be best to leave the seeds uncovered. 



(2) If sown without a nurse crop or during dry weather the 

 seeds should be very lightly covered — preferably to about J in. 

 to J in. 



In order to test the evidence given by the experiments here 

 discussed, field trials designed largely to ascertain the depth of 

 sowing under various operations, and to test the degree of excel- 

 lence of the stands, were also conducted during 1920 and 1921. 

 Tt is hoped that these results will be dealt with in a subsequent 

 article. 



