SOILS H 



Parts of Soil. — All soils are then composed of two parts, 

 the part made up of little particles of rock that we call 

 sand or clay or gravel, and the part made up of decayed 

 or decaying plants. This part is called organic matter, 

 vegetable matter or humus. Wherever crops are to grow 

 it is necessary that the soil have both particles of rock 

 and vegetable matter. In a sand pit there is no vegetable 

 matter in the soil and plants grow very poorly or not at 

 all. In an old drained lake-bed, where the soil is made 

 up almost entirely of vegetable matter (peat), crops do not 

 grow well. In farming it is very important that there be 

 a proper combination of these two parts. The part made 

 up of particles of rock is called mineral matter. . The part 

 made up of dead and partly decayed plants is called organic 

 matter. Plants contain both mineral and organic matter. 

 Questions: 



1. What is soil? 



2. How has soil gradually been formed from solid rock? 



3. What are the two important parts of soil? 

 Arithmetic: 



1. If there are 2 lbs. of ash in 100 lbs. of dry vegetable matter, 

 how many lbs. of ash in one ton (2,000 lbs.) of vegetable matter? 



2. If there is ^ lb. of vegetable matter in 10 lbs. of soil, how 

 many pounds of vegetable matter in 100 lbs. of soil? 



3. How many pounds of vegetable matter or manure would be 

 required to cover 12 acres, if six tons were applied to each acre? 



CLASSIFICATION OF SOILS 



In the study of soils one finds that there are many 

 different kinds. To enable us to talk and write about 

 soils, and to understand what is meant, it is necessary to 

 classify soils so that everyone will know what is meant 

 when a certain kind of soil is named. The most common 

 names applied to soils are gravel, sand, loam, clay and 

 peat. 



Gravel is the coarse part of the soil. The particles may 

 vary in size from that of kernels of wheat to stones as large 

 as hen's eggs. Such soil is not as a rule productive. The 

 particles are so coarse that they hold very little moisture 

 or plant food. Soil containing a large percentage of gravel 

 is called very poor or very light. 



