Moisture of the Soil. 487 



But once saturated, unlike sandy soil, it does not permit the 

 water to pass off by percolation and must wait until the sun's 

 rays and the winds have dried off the surface sufficiently to per- 

 mit of its being worked. Then, to conserve the moisture, fre- 

 quent shallow tillage should be given and crops should be sown 

 before the water has become exhausted. The slow passage of 

 the water towards the surface, by means of capilliary action, 

 furnishes plants with moisture and insures a successful start, 

 which is half the battle towards securing a successful crop. 

 King found that the loss of moisture during seven days from 

 April 29th to May 6th was 9.13 lbs. of water per square foot 

 greater on the unplow^ed than plowed land, equal to a rainfall 

 of 1.75 inches, or 198 tons of water per acre. Can it be afforded 

 to thus delay the spring plowing and the preparation of the soil 

 mulch? Then, the very evapoiration is a cooling process and the 

 soil, instead of becoming warm and of a proper temperatutre for 

 the germination of seeds, remains cold and uncongenial as long as 

 this wasteful process goes on. With sandy and gravelly soils 

 the difficulty experienced in the spring is not so great. They are 

 both permeable to water and furnish another means for its es- 

 cape besides evaporation. The water passes off by percolation 

 and the soil soon becomes warm and ready for the reception of 

 the seeds. But moisture can be conserved better on clay lands 

 than on sandy lands, because the loss occurs chiefly through 

 evaporation. It is upon clay or heavy lands, therefore, that the 

 value of the soil mulch is markedly apparent. 



Harroiving to save moisture. — The harrow, besides pulverizing 

 and fining the soil for the seed-bed, is most efficient in furnishing 

 a soil mulch. The spring-tooth harrow is in reality a cultivator, 

 and its action is similar to that of the cultivator. When used as 

 an instrument to conserve moisture, the teeth should penetrate to 

 the depth of about three inches, and to produce the best effect the 

 ridges left by it should be leveled off by a smoother which can 

 now be purchased as an attachment to the harrow. The tillage 

 of orchards by the harrow is now practiced extensively, and noth- 

 ing short of irrigation will so nearly meet the demands of trees 

 for moisture, particularly upon the heavier soils. 



