THE PEINCIPLES OF MANURING 187 



the number of plots required to carry it out in its en- 

 tirety. The plots may be of any size and may be 

 arranged in any order that is convenient. It is ad- 

 visable, however, that they should be not too large. 

 When the plots are small it is easier to compare the 

 effects of the manures, a smaller area is involved and 

 correspondingly smaller quantities of the manures are 

 required. The following arrangement is a compact one 

 and gives, perhaps, less trouble than any other in apply- 

 ing the manures ; the total area of land involved is 

 approximately a third of an acre and the quantities of 

 manure required are 1 -cwt. of superphosphate, or basic 

 slag, ^ cwt. of kainite, and J cwt. of nitrate of soda, or 

 sulphate of ammonia. The phosphatic manure (super 

 or slag) is applied to a piece of land 40 yards long by 

 20 yards broad, and the kainite to a similar piece over- 

 lapping half the breadth (10 yards) of the first through- 

 out the length. The nitrogenous manure (nitrate of 

 soda or sulphate of ammonia) is applied as a cross 

 dressing to the lower half, and extended 10 yards beyond 

 the margin of the manured piece. These instructions will 

 be more readily followed by comparing them with the plan. 



The phosphate is applied to the piece PI, P 2 , PS, . P , 

 shaded with vertical lines. The kainite is applied to 

 the piece K b K 2 , K 3 , K 4 , shaded with dots. The middle 

 portion K b K 2 , P 3 , P 4 , thus gets both phosphate and 

 potash ; of the other two portions, one gets phosphate 

 alone and the other gets kainite alone. The nitrogenous 

 manure is applied to the piece NI, N 2 , N 3 , N 4 , shaded with 

 horizontal lines. 



The result is altogether eight plots manured as follows : 



Upper half (P a K 2 ), phosphate alone. 



,, (K 2 P 3 ), phosphate and kainite (no nitrogen). 



,, (P 3 K 3 ), kainite alone. 



,, (K 3 0), no manure. 



