J.4c # 



In the opinion of the author, if soils arc equally well drained, 

 fertilizers may give as great an increase in yield on heavy- as on light- 

 textured soils. But because of poor drainage there are riany vineyards on 

 heavy soils on which fertilizers cannot be used at a profit under present 

 price conditions. 



The application of 30 pounds of phosx)horic acid per acre, nitrogen 

 and potash remaining the samic, on the average, increased the yield per acre 

 by 555 pounds of grapes on the light- textured soils and by 162 pounds on the 

 heavy woils. Although the increased yield from 30 pounds of phosphoric acid 

 was not so great as from 30 pounds of nitrogen, the gain from phosphoric 

 acid was more economical because 30 pounds of phosphoric acid cost only 40 

 percent as much as 30 pounds of nitrogen. The phosphoric acid cost for the 

 increased yield on the light-textured soils v/as §7.21 per ton of grapes and 

 |S4»69 on the heavy- textured soils. 



The gain per 30 pounds of potash, when nitrogen and phosphoric acid 

 remain the same, was 18E pounds of grapes per acre on the light-textiired 

 soils and S03 pounds on the heavy soils. The potash cost for the increased 

 yield was §15.16 on the light-textured soils and #13.60 on the heavy soils. 



Results from fertilizer tests conducted at the Fredonia, N.Y., vine- 

 yard laboratory since 1909 are listed in table 10. The vineyard at the labor- 

 atory is on a gravelly loam soil, which is one of the light-textured soils 

 in the Chautauqua-Erie grape belt. 



For 9 years plats 2 and 8 received application at the rate per acre of 

 100 pounds of sodium nitrate, 400 pounds of ^driod blood, 300 pounds of acid 

 phosphate, and 200 pounds of sulphate of potash. This vns equivalent to 47 

 pounds of nitrogen, 42 pounds of phosphoric acid, and 96 pounds of potash 

 per aero. For the last 15 years only 40 pounds of nitrogen were used per acre 

 all carried in nitrate of soda. The earlier quantities of acid phosphate 

 and sulphate of potash v/ero continued throughout the 24 years. These plats 

 averaged 1.32 tons more grrrpes per acre than did .plat No. 6 v/here no ferti- 

 lizer was applied. 



None of the vineyards studied in Chautauqua County and only 2 vineyards 

 in Pennsylvania that used approximately the sviae fertilizer in 19S7 a3 in 

 1928, received as much as 185 pounds of plant food per acre, the average 

 quantity used in the fertilizer tests on plats 2 and 8. However, the results 

 of the correlation study show that this quantity of plant food when applied 

 to the light-textured soils increased the yield 1.32 tons v/hich corresponds 

 with the total increase obtained at the vineyaj?d laboratory, Fredonia, N.Y. . 



Of the vineyards that were fertilized approximately the some in 

 1927 as in 1928, 4 Pennsylvania vineyards and 1 Chautauqua County vineyard 

 received: as much as 47 pounds of nitrogen in commercial fertilizer. The 

 experiences of Chautauqua-Erie grov/crs with vineyards on light- textured soils 

 compared with the results of the Fredonia fertilizier tests indicate increases 

 in yield, from the use of 47 pounds of nitrogen, of 1273 and 1627 pounds of 

 grapes respectively, (table 11.) 



