20 EXPERIMENT STATION. [Jan. 



abstract question it never will be settled. Each has earnest 

 advocates ; but the fact undoubtedly is that neither system is 

 always best. The best must vary with conditions. Neither 

 system possesses all the advantages. 



It is not proposed to enter ujion a full discussion of the sub- 

 ject here, but simply to present such statements as seem neces- 

 sary to guard against misunderstanding. 



The experiments here reported do not directly bear upon the 

 question. No comparison of the two systems has been made. 

 It will be admitted that the trees in this orchard have made good 

 growth and produced a fair amount of fruit. In estimating the 

 significance of these facts the character of the soil must be 

 kept in mind. It will be remembered that it is strong and re- 

 tentive, and that the moisture conditions are good. Under such 

 conditions, trees as well as grass find their need of water abun- 

 dantly supplied. 



Whether or not the trees w^ill be abundantly supplied with 

 moisture must, in the writer's judgment, determine in any par- 

 ticular case whether an orchard should be kept in sod. On the 

 lighter or gravelly soils there is always danger that the grasses 

 will rol) the trees of needed water. It is an easy matter to 

 supply plant food both for grass and trees, but not so with water. 

 On soils inclining to be dry the moisture must be carefully con- 

 served for the trees, and such tillage as will maintain a dust 

 mulch during the spring and early summer (Hale's horse leg 

 irrigation) is necessary for good results. 



It is of course true that allowing the grass and clovers to 

 remain on the ground when cut, as has been the practice in our 

 experiments, will provide a partial mulch which will help retain 

 moisture in the orchard soil ; but, even if this course be followed, 

 there is danger of water shortage at critical times in orchards 

 upon light or gravelly soils with subsoils of open texture, pro- 

 vided they are kept in sod. This danger is much reduced if the 

 grass produced in the orchard is gathered and spread under 

 the trees, thus providing a heavy mulch ; but, while this fact is 

 everywhere admitted, a large proportion of the most progressive 

 orchardists practice tillage in spring and early summer, sowing 

 a cover crop in late summer to furnish organic matter and 

 nitrogen, and in many cases to protect from injurious soil wash- 

 ing during the late fall, winter and early spring rains. 



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