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mind one cf the points just mentioned, viz. : that the upward move- 

 ment is more active when the particles ^re closely packed. It follows 

 then that the simple operation of loosening the surface soil with hoe 

 or fork to the depth of a few inches will stop the w^ter from rising 

 higher than just where the plant roots are situated below the surface 

 of the ground, md check loss by evaporaticn. This loss can also be 

 prevented by protecting the surface soil from the rays of the sun by- 

 means of a mulch of leaves or trash. The surface soil being theieby 

 kept cool, evaporation is checked. Both of these methods aie api li- 

 cable in the case of a tree plantation, such as an orange grove. 



If a circle with a radius of about 3 feet be marked around the tree, 

 the enclosed surface soil may be scratched up and a layer of trash be 

 placed around the base of the stem as well, a considerable amount of 

 w^ater will be saved for the use tf the plant. 



Further, as the wind is such a powerful factor in causing evapora- 

 tion, any method which will prevent the wind from blowing across 

 cultivated land, will tend to decrease the loss by evaporation. This 

 saving of soil moisture may be secured, as has already been mentioned, 

 by the planting of wind breaks. 



The reader can verify some of the above statements for himself in 

 the following manner : — 



Pack long glass cylinders full of dry soils of different kinds and 

 invert them in soup-plates of water. Note the different heights to 

 wl ich the water rises fn each case, and also the effects of loosening 

 the top layers or of changing the texture of soils by the addition of 

 clay, sand, humus, &c. 



(iii.) Transpiration. The method of this process will be discussed 

 under the heading of ' water in the plant.' It is the method by which 

 the plant breathes out through the pores of the leaves its excess of 

 moisture. Eemembering that for every pound of dry matter added to 

 the weight of a plant, about 300 pounds of water have to be taken in 

 at the roots, it will be realised what a large amount of water is removed 

 from the soil by the plants. The loss of water in this manner cannot 

 be controlled as can the losses by percolation and evaporation ; this pro- 

 cess must in fact be considered to be on the whole advantageous. Yet 

 we can reduce the loss by clean cultivation, i,e, hj allowing only 

 those plants which we are cultivating to take water from the soil. The 

 keeping down of weeds in a crop will therefore be the means of pre- 

 venting the loss not only of plant food but also of soil moisture. The 

 constant use of the hoe is to be advocated for this reason among many 

 others. 



These few remarks upon the relation of the soil to water may serve 

 to indicate the lines upon which success in the matter of conserving soil 

 moisture may be expected. It will be readily admitted that under con- 

 ditions such as those that exist in Jamaica, any operation that may 

 assist in this, to however slight an extent, is worthy of the agriculturists' 

 attention. 



2. JFater in the plants. — No practical agriculturist requires to be told 

 that an adequate supply of water is absolutely necessary for the healthy- 

 growth of the plant. To arrive at the reasons for this necessity, the 

 part played by water in the life history of the plant must be con- 

 sidered. 



