STATE HORTICULTUEAL SOCIETY. 115 



To test the effects of surface cultivation more exactly, and to 

 eliminate all sources of error, Mr. Hunt made some artificial experi- 

 ments, which must be rehearsed at this point. Two tin cans were 

 made, twelve inches deep by six inches in transverse diameter. 

 These had false perforated bottoms, and an opening below through 

 which water could be supplied and then corked tight. The cans 

 were filled from the same specimen of earth, after thorough 

 mixing. This earth was found, upon test, to have 14.3 per cent, of 

 water. When filled with the earth moderately pressed down, one 

 pound of water was added to each upon the surface, and one pound 

 placed in the bottom receptacle. Here now was moist earth having 

 a supply of water below, but no way of escape except from the sur- 

 face by evaporation. The two cans were placed side by side in the 

 open sunshine, and each lost, during three days, eight ounces of 

 water, behaving exactly alike in this respect. From this time on, 

 one was daily cultivated one and a half inches deep, and the other 

 left uncultivated. After seven more days the cultivated had lost five 

 additional ounces, and the uncultivated one nine and a half ounces — 

 almost twice as much! According to this, the water saved during a 

 week of dry weather by surface cultivation of an acre, would equal 

 one-fourth of an inch of rainfall, or thirty tons. Should not such 

 information put renewed vigor into the work of tillage during 

 drouth? 



Orchardists should note that two feet of soil from a blue-grass 

 pasture gave 12.3, and from adjoining land in corn, 15.2 per cent, of 

 water. There is scarcely a doubt but that orchard trees are much 

 better off when the general surface is cultivated in corn than when 

 pastured or mowed. Clover, closely cut and removed, is no better 

 than grass. Better than any crop is good and frequent tillage, an 

 inch or two in depth. 



When this title was announced, I hoped to make some similar 

 tests upon the effect of mulch, but did not succeed in getting the 

 work done. We know, however, that a good mulch is as efficient as 

 tillage. When exposed soil is thoroughly dry, that under a layer of 

 old straw is nearly saturated with water. If we estimate, as we have 

 done above, the total amount of water thus held in moist soil, and 

 then remember the rapidity of evaporation from naked, unstirred 

 soil, we should not be surprised at the puerile inefficiency of arti- 

 ficially watering trees and plants, and the decided advantage of 

 mulching. A coating of straw about a tree may hold more available 

 water than would be represented by the application to the naked 

 surface of hundreds of gallons monthly. When water is applied to 

 the surface, enough should be put on at once to wet deep down, 

 rather than more frequently moistening the surface, Mr. Smith, of 

 Green Bay, Wisconsin, found by experiment that it took 30,000 gal- 

 lons of water to wet down four inches. This great quantity is 

 equalled by a rainfall of one inch. If irrigation is to be practiced, 



