158 MASSACHUSETTS HORTICULTURAL SOCIETY. 



barnyard manure and lime ; and 34 use miscellaneous products. 

 Their average gross returns are about $100 per acre, and prac- 

 tically every grower reports that the crop is a profitable one. We 

 have liere a practical unanimity of opinion as to the necessity of 

 using manures, though a wide difference in practice in reference 

 to the kind of material used, which is in many cases due to the 

 relative cost of the various materials, rather than to definite 

 opinions concerning their relative value. 



The Kind of Manure to use. — The kind of manure to use ma\' 

 be discussed, first, as to whether it shall be natural or artificial, 

 and, second, if artificial, the kind of materials and the proportions 

 of the constituents most desirable. In reference to the relative 

 usefulness of yard manure and the best forms of chemical fertilizer 

 the data derived from the experiment on peach trees are instruc- 

 tive, and I simply add to that already given a financial statement 

 showing the relative values of the crops secured, less actual cost 

 of manures, and which does not include the cost of application. 



V. — New Value of Crops from Fertilizer and from 

 Natural Manures. 



Per year. 



Unmanured, 10 years, value of crop, $301.85 .... $30 18 

 Fertilized, 10 years, value of crop, less cost of fertilizer, 



$810.20 81 02 



Manured, 10 years, value of crop, less cost of mauure, 



$673.70 67 37 



Annual net increase from fertilizer 51 02 



Annual net increase from manure 37 19 



As has been already suggested, the amount of yard manure 

 applied may have been much larger than was necessary, though it 

 is very clearly siiown that the use of chemical fertilizer, under the 

 conditions obtaining in the experiment, was relatively more profit- 

 able than the manure ; hence, while it is hardly safe to conclude 

 that chemical fertilizers may in all cases be more profitable ttian 

 the manure, it was shown in previous tabulations that chemical 

 fertilizers did practically meet the demands for plant food ; 

 that is, the yield was but little greater from the use of barnyard 

 manure. 



In reference both to the kind of materials and to the proportions 



