104 SCHOOL AND HOME GARDENING 



When too much fertilizer lias beeu applied to crops in the 

 garden or field they are mure apt to suft'er because of this 

 extra fertilizer if the weather is dry. If hea\y rains come, 

 the plant-food is diluted and its wilting effects are reversed. 

 When enough water is present the food may be taken readily 

 into the plants. 



Care should be taken to never over-feed the plants unless 

 an abundance of rain or irrigation water is ready for use by 

 the crop. In dry climates, soils containing much salt near 

 the surface are found. These are called alkali soils. These 

 salts retard the growth of plants. They may be removed by 

 installing under-drainage. 



Eeclaimed salt niarshes along sea-shores may have an 

 excess of common salt left from sea water. Many kinds of 

 plants cannot be grown there until the rains of several seasons 

 have washed out the surplus salts. 



i6. Minerals in Soil Water. — Fill two clean quart cans with 

 water, one with clean fresh rain-water, the other with water from a 

 well or spring. Set them on a. stov^ and boil until dry. Note any 

 difference in the remaining matter in tlie cans. 



If the well-water is " hard," it will leave much white sedi- 

 ment on the sides and bottom of the can. This is observed 

 by all housekeepers in tea kettles. The other can will prob- 

 ably show no such sediment. If anything remains in the can, 

 it will probably be some dark material, as dust washed from the 

 air or roof by rain in falling. 



All water from springs, streams or wells dissolves mineral 

 matter of several kinds from soils. Such water inay contain 

 a large enough supply of minerals to materially aid the growth 

 of plants. 



17. Solubility of Lime. — Slake a lump of lime by placing it in 

 an open vessel with water enough to one-fourth cover it. As it 

 begins to heat and crumble, stir it and keep the whole lump moist. 

 As the slaking continues, gradually add a little more water until 

 the heating ceases. Then add about twice the amount. Stir well 



