Grade. 

 Date. . 



(32) EXERCISE 10 



Other Effects of Organic Matter 



Purpose. — To study the effects of manure and organic matter on the water- 

 holding capacity of the soil. 



Use the following soils: (1) sand; (2) sand with 10 per cent well-rotted 

 manure; (3) sandy loam; (4) sandy loam with 10 per cent well-rotted 

 manure; (5) muck; (6) sand v/ith 40 per cent muck. 



1. Take six glass or metal percolators (Fig. 13) and in the bottom of each 



place a small piece of folded filter paper. If necessary moisten the filter 

 paper in order that it may cover the bottom opening well. 



2. In percolator No. 1 place 500 grams of sand. 



3. Weigh out 450 grams of sand and mix thoroughly with 50 grams of well- 



rotted manure. Place in percolator No. 2. 



4. Place 500 grams of sandy loam in No. 3. 



5. With 450 grams of sandy loam thoroughly mix 50 grams of manure and 



place in No. 4. 



6. In percolator No. 5 place 500 grams of muck. 



7. For percolator No. 6 thoroughly mix 300 grams of sand and 200 grams 



of muck. 



8. Make the soil compact by allowing each percolator to drop six times 



upon a book from the height of two inches. Be careful to treat each the 

 same. 



9. Set glasses underneath each percolator and then add slowly to each 



sample 400 cc. of water. 



10. When percolation has ceased measure carefully the amount of water 



which has come through. Subtract this amount from the amount of 

 water which was added. This will give the amount of water held by the 

 soil. 



11. Record results in the following table. 



