-5- 



In the experimental vineyard located at "booster, Ohio, "Concord grapes were 

 grown, for nine years under pernianent straw mulch and cultivation plus cover crop 

 systems of soil management \Tith different rates of nitrogen fertilizer applicationo 

 The vigor of the vines as evidenced by pruning weights in 19<2 and 19^3 was signi- 

 ficantly higher under the mulch system of management. Mulched vines produced on 

 the average l6,9 lbs« of fruit per vine per year as compared -urith llcU Ibse per 

 vine per year from the cultivated vines. The petiole concentrations of nitrogen, 

 phosphorus, potassium and manganese were higher while calcium and magnesium were 

 lower under the mulch system of management. Highest total yields under cultivation 

 occurred when 80 lbs, per acre of actual nitrogen was applied each yearn With 

 mulch the highest total yield for the period 19U7 through 1953 occurred xuhere UO 

 lbs, actual nitrogen per acre per year was applied. It should be noted, hovirever, 

 that in 1953 highest yields with mulch occurred when no nitrogen was applied and 

 this has continued to be the case in I95I4 and 1955* 



The use of mulch resulted in the production of fruit containing lower soluble 

 solids and higher acids than did ciiltivation. The influence of season on these 

 constituents was nearly as great as was the influence of soil management system. 

 The reduction in soluble solids under mulch is believed to be the result of delayed 

 maturity and might be overcome by permitting a longer ripening period. 



During the first several years ivhile a umlch is being established, applications 

 of ho pounds of actual nitrogen per acre per year are recommended, ii^ith the rate 

 and kind of mulch used in this study such applications of nitrogen were beneficial 

 for the first six years of production. This period would vary with different kinds 

 of mulch material. Sawdust, for example, would decompose less readily and might 

 require prolonged applications of nitrogen, vfhereas more rapidly decomposing 

 materials which were relatively high in nitrogen might require less than six years 

 of nitrogen fertilizer application. 



The use of permanent mulch system of management for Concord grapes is believed 

 to be economically sound and to possess certain advantages not obtainable under 

 the conventional cultivation plus cover crop soil management system," 



Editor's Notes ; 



In the Ohio Experiment the mulch was applied originally at the rate of 10 tons 

 per acre and was replenished annually to maintain a layer of straw from 10 to 12 

 inches in depth. In our mulching experiments with raspberries conducted at Amherst 

 hay mulch was applied at the rate of 20 tons per acre in order tc have sufficient 

 mulch to suppress weed and grass growth. This amount of hay gave a mulch covering 

 of ii to 6 inches deep. 



As was stated in the excerpts from the Research Circular, the rate of fertil- 

 ization will vary considerable vri.th the mulch used. Most hay would probably be 

 higher in nitrogen than straw and vrill decompose more rapidly. It is known that 

 nitrogen deficiency may develop if appreciable amounts of carbonaceous organic 

 materials such as sa\'vdust are used as mulch. This deficiency develops because the 

 bacteria which decompose the organic matter tie up the soil nitrogen in an unavail- 

 able form. 



