WEEDS 119 



Here are some mixtures that have proved satisfactory: 



1. Barley, cue-half bushel ; erimsou clover, six pouuds. 



2. Barley, oue-half bushel ; winter vetch, one peck. 



3. The above combinations with buckwheat instead of barley. 

 This general type of mixture is best because it contains one 



rank grower to check the growth of the trees and to furnish humus 

 and one perennial legume to add nitrogen, act as a "mat" for 

 the windfalls and to catch and hold the leaching nitrates. Look 

 over the list of purposes which the cover crop is expected to serve 

 and see how well either of these mixtures will fill the bill. Take 

 No. 1 as an example. Both barley and clover prevent washing 

 fairl.y well, but the clover is especially good. The rank gi'owth 

 of the barley will check the growth of the trees, and add much 

 humus. It will also hold the snow and leaves, and assist in pre- 

 venting winter injury. The clover on the other hand, while not 

 strong on these points, grows late in the autumn, and so takes up 

 the soluble food at that time, it adds nitrogen, is excellent for 

 protecting the windfall fiiiits, and assists materiall^^ in prevent- 

 ing winter injury. 



The principal objection to a mixture is that it takes more 

 time to sow it since seeds must either be mixed or else two sowing 

 operations will be required, one for each seed. 



Weeds. — It seems worth while to add that some orchard men 

 make use of weeds as a cover crop. Where they can be depended 

 upon for a good stand they are better than nothing. In fact there 

 is probably no really legitimate objection to them, except with a 

 very few such as witch grass. Of course they add no nitrogen. 



QUESTIONS 



1. What is a corn crop? 



2. What are the most important \ises of orchard cover crops? 



3. Why should the fall growth of trees he checked? How does the cover 



crop assist in this? 



4. What class of cover crops add nitro<2:en to soils? 



5. Is there any advantage in having the cover live over winter? 



6. Give a list of the crops most suitahle for winter covers in your section. 



7. Discuss the advantage of several of these. 

 S. What ones are legumes? 



0. What ones live over winter? What ones are killed by fall frosts? 

 JO. What is the objection to perennial crops for this purposp? 



