STUDIES IN NATURE 



the soil, and thus replenishing the supplies of 

 food for the plants, is called manuring, as we 

 most of us know, and like drainage and irriga- 

 tion requires to be done carefully. Plants require 

 tiny amounts of many sorts of things ; they often 

 want them in one particular state or form, and 

 too much manure may be as bad for them as too 

 little. They will die of something like thirst if 

 the ground is over-manured, for the water in the 

 plants, instead of passing up into the leaves and 

 flowers to take the place of that given off into 

 the air, will go down into the ground to try to 

 weaken the strength of the mixture of substances 

 in the soil. 



Another effect of adding manure is to warm 

 the soil, and in cold districts this is very neces- 

 sary. Farm-yard manure is decaying animal 

 and vegetable matter, and, while the process of 

 decay goes on, and the substances in it are 

 broken up and altered in character, the heat 

 which was stored up during the period of growth 

 is given off and passes into the soil. We often 

 see steam rising from a heap of manure, and 

 know that it is used in many ways, especially in 

 the garden, as a source of heat. Manure may 

 also do good by making heavy clay soils less 

 dense by the mixture with other substances. 

 In this way sun and air get in more easily, and 

 the land becomes less cold. 



We have spoken of the results of drainage, 

 of irrigation, and of manuring. We must now 



(ICO) 



