10 SOILS AND FERTILIZERS 



tain some plant food material. Weigh the soil that is placed in each 

 pot, mixing with it fertilizer in the following proportions : 



Pot 1, nitrate of soda one part to five thousand parts of soil. 

 Pot 2, acid phosphate, one part to five thousand parts of soil. Pot 

 3, muriate of potash, one part to ten thousand parts of soil. Pot 4, 

 all three of these carriers, each at the rate specified above. Pot 5, 

 no fertilizer. Mix the fertilizer and soil thoroughly before placing 

 in the pots. Plant a dozen or more barley seeds in each pot. Add 

 water in sufficient quantity to make the soil moist but not too wet. 

 Place the pots in a place that is moderately warm during the day, 

 where they will not freeze at night, and where there is abundant 

 light. When seedlings are a week old, thin to ten. Allow plants to 

 grow for use in laboratory exercises in Chapters XI, XII and XIII. 

 Observe growth in each pot. 



