128 EXPEKIMENT STATION EECOKD. 



"When used alone, or in combination with each otlier only, nitrogen and potash 

 have produced but a very small increase, and have always been thus used at a heavy 

 financial loss. 



"The complete fertilizer, containing all three constituents, has produced a much 

 larger total increase than the sum of the increase jjroduced by the constituents used 

 separately. 



"When the cereal crops have been grown continuously on the same land the 

 maximum increase of crop per pound of fertilizing constituents applied has been 

 obtained when these constituents were used in approximately the same ratio to each 

 other in which they are found in the crop; but the total recovery of fertilizing con- 

 stituents in increase of crop, under continuous cropping, has never exceeded 60 per 

 cent of the quantity applied in the fertilizer. 



"When the cereals have been grown in rotation with clover the recovery of nitro- 

 gen has, under favorable conditions, exceeded the amount applied in the fertilizer; 

 but even under these conditions the recovery of phosphoric acid and jwtash has 

 remained far below the quantity applied in the fertilizer, when maxinunn yields 

 were reached. 



"Thus far in these experiments the surplus nitrogen accumulated by a crop of 

 clover, the roots only being left in the ground, has not been more than sufhcient to 

 satisfy the demands of the one crop immediately following the clover. 



"At the prices at which mixed fertilizers are sold in Ohio the attempt to furnish 

 all the nitrogen as well as all the phosphoric acid and potash required to produce 

 increase in cereal crops grown in continuous culture, has invariably resulted in 

 pecuniary loss, although very large increase of crop has been thus produced. 



"The rotation of cereals with nitrogen-gathering crops, therefore, has been shown 

 to be absolutely essential to the profitable use of conunercial fertilizers in any form. 



"The increase of crop per pomid of fertilizing constituents applied has generally 

 been smaller when l)arnyard manure was used as the carrier of fertility than when 

 chemical carriers were used; but the lower cost of barnyard manure has made it 

 possible to use this material with profit when the use of commercial fertilizers 

 resulted in loss. 



"A marked superiority is indicated from manure which has been kept under 

 cover until required for use over that which has been exposed, even for but a short 

 time, in an open barnyard, and it seems possible to materially increase the effective- 

 ness of manure by treating it with nitrogen-fixing materials. 



"Nitrate of soda has shown itself to be the most effective of the carriers of nitro- 

 gen employed in these experiments, with sulphate of ammonia, dried blood and 

 linseed-oil meal following in the order named. 



"Of the four carriers of phosphoric acid used, basic slag and dissolved boneblack 

 show the highest effectiveness, with raw bone meal and acid phosphate not far 

 below. 



"The tendency to excessive production of straw in wheat and oats is apparently 

 due in part to climatic and in part to soil conditions, and the remedy apparently 

 lies in systematic rotation, combined with judicious selection and distribution of 

 fertilizing materials." 



Commercial fertilizers, S. W. Johnson, E. H. Jenkins, et al. 



{Connecticut State Sta. Rj^t. 1899, 2>t- ^^ PP- ^9^)-— This includes a 

 statement of fertilizer sales in Connecticut in ISOO, the text and an 

 abstract of the State laws relating to fertilizers, a list of manufacturers 

 complying with the laws, notes on the sampling- and collecting of fertil- 

 izers, explanations concerning the analysis and valuation of fertilizers, 

 a review of the fertilizer market for the year ended October 31, 1899, 



