MANUAL OF GENERAL AGRICULTURE. 



4. DETERMINATION OF TOTAL MOISTURE IN 

 THE SOIL. 



Materials: Four tin pans, sheet iron drying oven*, 

 samples collected in Exercise 2. 



Number, mark with your initials and accurately 

 weigh four pans. Record weights in your note book. 

 Run all your experiments in duplicate for the sake of 

 greater accuracy. 



Place in pans 1 and 2, 50 grams of surface soil, and 

 in pans 3 and 4, 50 grams of subsoil. Put them in the dry- 

 ing oven for at least five hours at a temperature of 100 

 to 110 degrees centigrade. Cool to room temperature 

 and weigh at once. The loss in weight represents the 

 total moisture content of the soil. 



Tabulate the results as follows: 



TOTAL MOISTURE IN SOILS. 



Questions: 1. What were the weather conditions 

 at the time of taking the samples? 2. Approximately, 

 when was the last heavy rain? 3. Does the soil or sub- 

 soil have the most moisture? "Why? 



*A better oven is of copper set on a strong iron frame. It 

 should be about 10 in. high, 10 in. deep, and 12 in. wide. The 

 oven is provided with a centigrade thermometer and has a vent 

 for the escape of moisture. It costs approximately eight dollars. 

 As it is needed throughout the entire course, it is advisable to 

 obtain one. 



