EXERCISE VIII 



THE EFFECT OF COMMERCIAL-FERTILIZER SOLUTIONS 

 ON SEEDS 



Material. Clover seed, 1 per cent solution of sodium nitrate, 

 1 per cent solution of muriate of potash, 1 per cent solution of 

 phosphoric acid, and a saturated solution of limewater. 



Apparatus. 100-cc. wide-mouthed bottles, Geneva seed-testers. 

 It has long been known that certain chemical fertilizers, as well 

 as certain forms of other chemicals, have some influence on the 

 seed, in the soil solution as well as in an aqueous solution. 



'1. Count out four lots of one hundred seeds of the clover. 

 Place each lot in a wide-mouthed bottle and cover them respec- 

 tively with a 1 per cent solution of sodium nitrate, a 1 per cent 

 solution of muriate of potash, and a 1 per cent solution of 

 phosphoric acid, allowing each lot to remain in its respective 

 solution for twenty-four hours. Remove each sample, and ger- 

 minate in the Geneva seed-tester. Place the fourth batch un- 

 treated in the seed-tester to serve as a check. Tabulate and discuss 

 your results in each case. Plot a curve showing the per cent of 

 germination with each of the fertilizers and also when no ferti- 

 lizer is used. Does it pay to allow a commercial fertilizer to 

 come in direct contact with the seed ? Discuss. 



2. Mix in equal proportions a saturated solution of limewater 

 with a 1 per cent solution of each of the following : sodium 

 nitrate, muriate of potash, and phosphoric acid. Now with each 

 solution treat such a batch of seeds as in 1, and germinate. 

 Does the addition of the limewater to the seed aid in preventing 

 any detrimental effect of the commercial fertilizers ? 



Do the fertilizers all act alike on the different seeds ? Which 

 fertilizer shows the most injurious effect ? Are the seeds hastened 

 or retarded in germinating by the use of fertilizers ? Discuss. 

 Tabulate your results, and plot a curve showing what effect 

 the limewater has when added to each of the fertilizers. 



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