11)8 



Journal of the Department of Agriculture. 



^•ineyard to such experiments. The follnwinp' is a simple plan which 

 might be adopted: — 



This choice or arrangement of plots is based upon the fact ihat 

 we know tliat the prime requirement of all vineyards is phosphoric 

 oxide. 



The average of the yields of Plots (1), (4), and (7) will give us 

 the yield without fertilizer, i.e. the check. The increased yield of 

 Plot (3) over this check shows the effect of phosphoric oxide alone. 

 The effect of nitrogen we derive in two ways. Plot (2) -Plot (3) shows 

 whetl;er nitrogen gives any increased yield over P alone, and Plots 

 (5)-('6) show the additional increase due to N when both P and K 

 are added. 



The eft'ect of potash is also obtained in two ways. Plot (6)-Plot 

 (3) shows the increase over P alone due to using K, and Plot (5)- 

 Plot (2) shows whether K produces a further increase over P plus N. 



If Plot (5) gives the highest yield of oil, evidently the "com- 

 plete " mixture is best. Whether it pays or not can be ascertained by 

 subtracting the check yield and calculating the money value of the 

 increase. 



If Plots (5) and (2) are practically the same, it is evident tliat a 

 complete mixture is not necessary at i)resent, though it may be in 

 future as the soil becomes poorer in potash. 



If Plots (5) and (6) are practically the same, nitrogen is evidently 

 not necessary at present, and so on. 



The size of the plots will be a matter of convenience, but 

 ordiiiarily the larger the better. Al)out 100 vines per jjlot would be 

 a good number, i.e. each plot about 1/36 morgen where the vines 

 are planted 5 feet by 5 feet. The most important point is to select 

 as uniform a strip of vineyard as possible, and, if the vineyard is on 

 a slope, the strip chosen should cut evenly across the slope (not up 

 and down). The strip is then divided cross-wise into seven plots as 

 shown in the illustration, each containing, say, 100 vines (10 x 10) 

 or 96 vines (8 x 12 or 6 x 16), or any other suitable number. 



Between each plot and the next one should be left at least one 

 row of vines, preferably two, so that the vines in one plot cannot 

 get food from the plot next door. 



Apart from the manures added, the treatment of all the plots 

 must be identical. Observations should be made as to growth, and, 

 finally, the weight of grapes from each plot carefully recorded. If 

 a good site has been chosen, the growth and yields of the three 

 untreated plots should be about the same. 



