152 BOARD OP AGRICULTURE. [Jan., 



acid is the requisite. There are thirty thousand farms in 

 Connecticut; when these experiments shall have been tried 

 on thirty thousand farms, then we shall be in a position to 

 answer the question statistically. 



I have seen an account of a farm which for a dozen years 

 or more was run by chemical manures alone. All the stable 

 manure produced (and a good many cattle were kept), was 

 sold off and commercial fertilizers were used instead. It was 

 a large farm, under a regular and rather complicated eight- 

 year system of rotation of crops, a thing which we do not 

 know much about here in New England, and a very important 

 factor, too, in the management of a large farm, when it can 

 be looked after properly. That farm, went on increasing in 

 its productiveness during those dozen years, yielding annually 

 a large amount of stable manure, which was sold to advantage 

 to gardeners and others in the vicinity, who could not get along 

 Avithout it, or thought they could not, and " chemicals" and 

 other fertilizers were purchased to make up the deficiency. 

 That is a case that stands on record as a fact. It is not, 

 however, the general rule. Mr. Lawes has been for forty 

 years raising wheat on one field without the application of 

 any fertilizer whatever, and he has proved that in its soil 

 there are ample stores of phosphoric acid, of potash, and of 

 everything that a heavy wheat crop requires, but only nitro- 

 gen enough to give about fifteen bushels to the acre. By 

 adding a certain number of pounds of sulphate of ammonia 

 or nitrate of soda, Mr. Lawes easily doubles the crop. He 

 also doubles the crop by the application of stable manure ; but 

 he has to put on four or five times as much nitrogen in stable 

 manure to get this double crop as is needful to apply in the 

 shape of ammonia salts or nitrate of soda. Tliat land is rela- 

 tively destitute of available nitrogen. There are thousands of 

 pounds of unavailable nitrogen to the acre in the soil, but the 

 annual change of nitrogen from an unavailable to an available 

 condition is only sufficient for fifteen bushels of wheat to the 

 acre. But as these experiments go on, after a long period of 

 .time, doubtless, a change will come over that soil. Very likely 

 the nitrogen will outlast the phosphoric acid, and after many 



