Il6 AGRICULTURE 



They are rarely so cheap or so good for the soil as natural 

 manures; some injure soil- texture and water-holding power. Most 

 of them, indeed, are crop stimulants rather than soil improvers. 



Rules for Use. Two rules should govern the farmer's use of 

 commercial fertilizers. 



First : To enrich his soil and increase his crop, he should depend 

 chiefly on tillage, rotation of crops, and natural manures. 



GRASS ON FERTILIZED AND UNFERTILIZED LAND 



This grass was sowed in September. The field on the left received no further care ; that 

 on the right had in the spring a top dressing of 250 Ib. of muriate of potash and 250 Ib. of 

 nitrate of soda to the acre, at a cost of $18.68. The manured crop yielded 6,567 Ib. of 

 cured hay to the acre; the unmanured yielded 1,284 Ib. The hay sold for $16.00 a ton. 

 What was the profit from the use of the fertilizer? 



Second: He should supplement these with the proper amount 

 of the commercial fertilizers that experience proves best and cheap- 

 est for his soil and his crops. 



Guano. One of the best commercial fertilizers is guano 

 (gwa'no), which is especially rich in nitrogen and phosphoric 

 acid. Guano is the manure and remains of fish-eating sea fowls. 

 For countless centuries these birds frequented the rocky islands off 

 the Pacific coast of South America. There they hatched and reared 

 their young. Their manure and dead bodies accumulated, and in 



