18, 



Results from the Miner and Barnes vineyards are given in table 12* 

 At 1928 prices, the increased yields did not pay for the fertilizers. The 

 largest losses, usually over $20 per acre, occurred when all 3 plant foods 

 ?/ere applied. The fertilizer costs were high because dried blood was used 

 at the rate of 400 pounds per acre. None of the interviewed growers bought 

 dried blood, except as it was included in mixed goods • 



The increased yield at the Fredonia laboratory vineyard more than 

 paid for the fertilizer in all the tests but one. The chances that the differ- 

 ences in yield between the fertilized and unfertilized plats in the Fredonia 

 laboratory vineyard experiment might occur* by chance are remote. However, 

 for most of the fertilizer tests on the other vinqyards reported for 4 years 

 the differences are not very significant, for such differences could frequently 

 occur by chance, (table 120 



The resiolts of the fertilizer tests by Mr. Oladwin and the ' experiences 

 of the Chautauqua-Erie grape growers, as summarized in this study, indicate 

 that, at 1928- prices, fertilizers in the Chautauqua-Erie belt cannot be 

 profitably applied to vineyards located on poorly drained soils, but can be 

 profitably applied to vineyards located on well-drained soils. It is assumed 

 that the important difference betv/een the light- and heavy-textured soils in 

 the Chautauqua-Erie belt is one of drainage. Further studies and experiments 

 should bo made to give a bettor understanding of the differences between these 

 soils. 



Grape yields on the Fredonia laboratory test plats have been declining. 

 (table 13.) Daring the last 7 years, 1924-1930, the unfertilized plat yielded 

 only about one half as much as during the first 7 years of the cxperinent. On 

 the fertilized plats the decline in yield was less, varying from 26 to 42 per- 

 cent. The increase in yield on the fertilized plats over the check plat v/as 

 therefore greater during the last 7-yoar period than in the earlier periods. 

 The plats receiving each kind of fertilizer - nitrogen, phosphorous, and 

 potash - maintained yield better than did the other plats. 



Relation of Use to Yields, Michigan Vineyards 



Although lack of drainage limits the production in the Chautauqua-Erie 

 belt, excessive drainage limits the production in southwestern Michigan. The 

 soils about Lawton and Mattawan, Michigan, were mapped chiefly as Coloma sandy 

 loam or Plainfield sand. These soils arc so open and porous that their 

 moisture-holding capacity is Iott. The yields of vineyards on these soils 

 average less than the yields of the vineyards west of Paw Paw, which r/ero on 

 Fox sandy loam, v/here the drainage is adequate but not excessive. 



Not enough vineyards v/ere studied in Michigan to permit averaging those 

 that received the same fertilizer treatment in 1927 and 1928, as was done for 

 the Chautauqua -Erie vinoyaj?ds in table 8. The Michigan vineyards were sorted 

 according to the average application of nitrogen in 1927 and 1928 i (table 14.) 

 If the application in 1927 was not reported, the 1928 fertilizer application 

 was used in the computations. 



