The orchard practice of applying sufficient poor hay or similar 

 material to suppress the growth of grass and weeds over most of 

 the soil occupied by the tree roots keeps the soil a little cooler in 

 hot weather and warmer in cold weather, conserves soil moisture 

 in dry periods, and after the first two years furnishes plenty or 

 an excess of soil nitrates. This excess seems not to interfere 

 with satisfactory performance of the trees. 



There can be little doubt that such an abundance of mulching 

 material will supply sufficient soil nutrients other than nitrogen. 

 It prevents soil erosion and must favor the absorption of rainfall 

 by the soil. The normal top-root ratio of the tree is not disturbed. 



This system may be rather expensive under some conditions; 

 the cost will vary greatly but the work can be done over a con- 

 siderable period of time, possibly when other work is not so 

 important. 



The amount of air-dry material necessary to bring about 

 these conditions seems to be not much less than one pound per 

 square foot per year for the area actually covered. It is possible 

 that a somewhat smaller amount would give quite satisfactory 

 results. 



Mulching is most advisable under certain conditions: (1) 

 where there is a convenient and cheap source of material, (2) 

 on comparatively steep slopes, (3) on rough, stony land, (4) on 

 loose, gravelly soils likely to suffer from lack of water during 

 dry periods, (5) for varieties apt to drop heavily near harvest 

 time, and (6) where root injury from cold is feared. 



The possible objections are: (1) cost, (2) danger of fire, and 

 (3) danger of injury from mice. 



