EXPERIMENTS OX WHEAT. 17? 



rich for wheat. But on a clayey soil, such is evidently not the case. 

 And tue fact is a very important one. When we apply manure, 

 our object should be to make it as available as possible. Nature 

 preserves or conserves the food of plants. The object of agricul- 

 ture is to use the food of plants for our own advantage. 



"Please be a little more definite," said the Deacon, " for I must 

 confess I do not quite see the significance of your remarks." 



" What he means," said the Doctor, " is this : If you put a quan- 

 tity of soluble and available manure on land, and do not sow any 

 crop, the manure will not be wasted. The soil will retain it. It 

 will change it from a soluble into a comparatively insoluble form. 

 Had a crop been sown the first year, the manure would do far more 

 good than it will the next year, and yet it may be that none of the 

 manure is lost. It is merely locked up in the soil in such a form 

 as will prevent it from running to waste. If it was not for this 

 principle, our lands would have been long ago exhausted of all 

 their available plant-food." 



" I think I understand," said the Deacon ; " but if what you say 

 is true, it upsets many of our old notions. We have thought it de- 

 sirable to plow under manure, in order to prevent the ammonia 

 from escaping. You claim, I believe, that there is little danger of 

 any loss from spreading manure on the surface, and I suppose you 

 would have us conclude that we make a mistake in plowing it 

 under, as the soil renders it insoluble." 



" It depends a good deal," said I, " on the character of the soil. 

 A light, sandy soil will not preserve manure like a clay soil. But 

 it is undoubtedly true that our aim in all cases should be to apply 

 manure in such a form and to such a crop as will give us the great- 

 est immediate benefit. Plowing under fresh manure every year for 

 wheat is evidently not the best way to get the greatest benefit from 

 it. But this is not the place to discuss this matter. Let us look 

 at the result of Mr. Lawes' experiments on wheat the third year : " 



