Report of the Horticulturist. 441 



it helps to keep the soil filled with humus, but because it seizes 

 upon soluble plant food in the soil and makes use of valu- 

 able fertilizing material which might escape in the drainage 

 waters were the ground not occupied. The nearer the ground 

 is to being filled with the roots of orchard trees, the less is 

 the liability to lose i>laut food through drainage waters. 



Another advantage to be gained by the use of cover crops is 

 that some kinds of plants may be used for this purpose by which 

 the amount of nitrogen compounds in the soil may be increased. 

 Since nitrogen is the most expensive element of plant food in 

 commercial fertilizers, and because without a sufficient amount 

 of it neither orchard trees nor farm crops can be brought to 

 their highest productiveness, the use of cover crops has an im- 

 portant bearing on the problem of keeping orchards up to the 

 highest productiveness in the most economical way. 



The object of this article is not to set forth in detail the rea- 

 sons for using cover crops, but to give a brief account of the 

 growth of various plants which were tried for cover crops, the 

 seeds of which were sown about August 1, 1S9G, in the orchards 

 at this Station. 



Canada Peas and Buckwheat. 



Canada peas, at the rate of two bushels per acre, and buck- 

 wheat, one-half bushel per acre, were sown in a bearing apple 

 orchard. The plants made an even, rapid, vigorous growth, so 

 that by the latter part of September they averaged nearly two 

 and one-half feet in height in their natural recumbent position, 

 but when straightened up they were four feet high. The vines re- 

 mained green and vigorons until late in the fall. (See plate 

 XXX, taken October 19.) In this and the following plates the 

 yard stick which appears in the foreground will help in forming 

 an idea of the height of the cover crop. About half of the vines 

 were still green December 1. Part of this crop was sown on 

 heavy clay soil, where crimson clover was sown as a cover crop 

 the year before, but did not prove a success. It is interesting 

 to note that where crimson clover failed, Canada peas made 



