EXPERIMENT STATION BULLETINS. 367 



become a nuisance and tlioj do no! coiislil iilc ;in addilion io (lie soil, 

 as some olhci" ])lants do. 



It is very desirable lo have some ''cover crop" j!;i'o\viii^ uniformly ui)on 

 the soil after cultivation has been stop^K'd. At this time, the trees do 

 not need the plant food or moisture that these "cover crops" will utilize 

 and so they are not competing with the trees but co-operating. 



There are numerous plants that are well adapted for cover crop pur- 

 I)Oses, some more desirable than others, largely depending upon the con- 

 dition or method of handling the orchard soil or location. 



A brief reference to the most common systems of orchard soil manage- 

 ment is necessary to understand what kind of plants can be used to the 

 best advantage under the ditferent systems. 



In Michigan there are three more or less general systems of handling 

 orchard soils. 



1. The sod mulch system. A permanent sod is maintained and as 

 the grass is cut, it is allowed to remain on the ground to decay. Manure 

 or commercial fertilizer when used is applied upon the sod. A mulching 

 of straw is sometimes spread beneath the trees. 



Cover crops cannot, of course, be used in this system of orchard soil 

 management. 



2. The orchard soil is not plowed but harrowed or disced as early 

 in the spring as practicable. 



The soil is ke})t cultivated by frequent harrowings until mid-summer 

 and at that last cultivation, a cover crop is sown. 



Under this system a cover crop plant that dies in the winter is better 

 than one that grows in the spring. It is difficult to work into the soil 

 in a satisfactory way with a harrow or disc, a large live plant. The fruit 

 grower who handles his soils in this way should use for a cover crop, oats 

 and peas, barley, buckwheat or some such plant. 



3. The orchard soil is plowed early in the spring and kept cultivated 

 by frequent harrowings until mid-summer when a cover crop may be 

 sown. Since plowing is practiced, a large growth of any plant can be 

 easily handled and plants that live over winter and grow in the spring 

 can be utilized. 



The advantages of having a cover crop in an orchard or vineyard are 

 generally well known but important enough to be mentioned again. 



1. As has been previously mentioned, their growth late in the season 

 has a tendency to check the growth of the trees and this results in the 

 hardening of the new wood so that it is in good condition for the winter. 

 Trees that grow late in the summer or fall are often very seriously in- 

 jured by the low temperature of the winter. 



2. The hard rains of both fall and spring will wash the rich top soil 

 very seriously on slopes unless the ground is covered with a good growth 

 of some plant, the roots of which will tend to hold the soil together and 

 prevent the washing. 



3. A cover crop will catch the leaves and prevent them from blowing 

 away. In addition to the fertilizer in the leaves, they add humus to the 

 soil. A Baldwin apple tree of bearing age and normal size produced 

 80 lbs. of leaves, a R. I. Greening 81 lbs., Champion peach 46.28 lbs.. 

 Elberta peach 38.26 lbs.. Hills Chili peach 52.71 lbs., Kieffer pear 38.62 

 lbs., Italian prune 19.56 lbs.'. Such a mass of material from a tree 

 should be saved on most soils. 



iNew York Agricultural Experiment Station Bulletin 246. 



