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REPRESENTATIVE PLANTS 



1. Naturally, by small amounts of atmospheric nitrogen 

 combining in the ground with bases to produce nitrates. 



2. Naturally, by the decay of nitrogen-fixing bacteria 

 nodules ; often introduced artificially by sowing clover, 

 alfalfa, cowpeas, soy beans, etc. 



3. Artificially, by animal waste, as manures. 



4. Artificially, by the introduction of nitrate of soda as a 

 commercial fertilizer. 



Of these methods the best is by the growth of the legume 

 plants and eventual plowing under. This adds to the soil 

 the nitrogen of the bacteria nodules and humus from the 

 decaying plants. 



A test that could be easily carried out, if the pupil has 

 land to experiment with, is to take four plots of equal size, 

 side by side, numbered 1, 2, 3, 4. 



Spade them all, and in July sow on No. 4 crimson clover. 

 Cover No. 3 with ordinary stable manure about Oct. 1. Do 

 not touch 1 and 2. The following spring spade all the plots 

 and plant to some one crop, as sweet corn, beets, or cabbage. 

 Sow carefully and evenly over No. 2 nitrate of soda and 

 powdered earth mixed (at the rate of 100 pounds of nitrate 

 to the acre.) Put nothing on No. 1. Compare the harvest 

 on each plot for early maturity, quantity, and quality. 



13. Flowers of the Violet Family (Irregular) — 

 Violets and Pansies 



Plants and place of growth. Plants ought to be obtained 

 in flower and also when the fruit is well advanced. For 



