The Problem of Impoverished Lands. 125 



It passes off tlirough the leaves. 



19. Is the ivater which evaporates from the soil of any direct use 

 to the plant? 



Xoj not of itself. 



20. The plant needs water ^ — it sweats it ont : how shall we 

 manage so that the plant can have all the water it needs f 



k\\ abundance of water goes into the soil (in New York) every 

 year, but it is not equally distributed. When the plants need it 

 most is the time when there is usually the least rain. The only way 

 we can help the plants (unless we irrigate) is to preserve the moist- 

 ure so that it becomes available when it is most needed. This may 

 be done by draining the land, and in this way increase the storage 

 capacity of the soil (See Lesson No. 2) ; and by keeping a good 

 earth-mulch on the surface so as to prevent, as much as possible, the 

 evaporation of the water from the soil. 



21. Write doion all the substances {or materials) you hno^v which 

 the plant must have in order to live and grow. 



Mtrogen, phosphorus, potash, lime, iron and sulfur were given 

 in Lesson No. 3 as some of the necessary plant-foods. Carbon, 

 hydrogen and oxygen are also necessary. 



22. Which one of these does nattire supply in sufficient abund- 

 ance^ witho^U any thought on your part f 



Carbon. 



23. What ones can you help nature to supply f 

 Nitrogen, potash, phosphoric acid, lime and water. 



24. Name all the congenial conditions {or agencies) tvhich the 

 plant mtcst have in order to be comfortable and to grow. 



A certain temperature ; a certain water supply ; a certain amount 

 of humus ; good texture ; and a sufficient supply of plant-food. 



25. What ones of these can you help natiire to supply or maintain? 

 We can influence the water supply, add plant-food and humus, 



and maintain good texture. 



