IMPBOVING TEE SOIL 67 



wetting it, and not remain in pools either on the surface or some httle 

 distance below it. Even in the case of plants which grow naturally 

 in marshy or boggy situations stagnant water is injurious and means 

 should be taken to prevent its accumulation. 



Farmers are often obliged to drain their land by laying pipes at 

 various depths, or by having trenches or ditches made at various inter- 

 vals so that the water may be carried away from the soil in which 

 their crops are growing. In the cultivation of flowers, fruits and 

 vegetables perfect drainage is often secured by thoroughly trenching 

 the soil, deeply digging it, and ridging it up as explained. I have seen 

 neglected kitchen-garden ground so sodden with water that the surface 

 became covered with the green slime so characteristic of stagnant 

 moisture. But after it had been well trenched and left exposed during 

 the winter months it became quite porous, and now bears good crops 

 annually. The soil, therefore, cannot be turned up too much, and if the 

 subsoil is too poor to bring to the surface occasionally it may be at 

 least turned over as explained under 'Double digging.' 



In wet heavy soil all the stones and rougher portions may be placed 

 at the bottom to act as drainage much in the same way as ' crocks ' in 

 a flower-pot. Flower borders very often require to be thoroughly 

 drained with a layer of brickbats, clinkers, stones, mortar-rubbish &c. 

 at a depth of three or four feet when devoted to the cultivation of 

 certain plants, such as Oncocyclus Irises (p 918), Mariposa Lilies 

 (p. 872) and other plants which readily succumb to stagnant moisture 

 at the roots in our climate. 



The reason why wet ground is so injurious to plant life is because 

 the temperature is lower than in drained land, and the passage of air 

 gases through the soil is prevented. As long as the soil is in a wet 

 condition so long will the heat of the sun be used to evaporate the 

 water instead of warming the soil. Even in the hottest summer, the 

 warm water will come to the surface, while the cold will sink down 

 and chill the roots and retard, if not altogether stop, their absorptive 

 process as described at p. 27. And thus the plants suffer perhaps in 

 the midst of an abundance of plant food which is not placed at their 

 disposal in a proper state owing to bad drainage. 



LIMING THE SOIL 



Besides digging and trenching the soil, it may, if in a wet condi- 

 tion, also be improved by the addition of lime, which is a most important 

 agent in fertilising the soil. It not only ' sweetens ' sour wet land, but 

 makes.it drier and more porous, and thus increases its temperature. 



JP2 



