CONTRIBUTIONS FROM THE WISLEY LABORATORY. 319 



3. Plot 3. Farmyard manure ...... 95 



4. ,, 2. Farmyard manure plus bacterized peat . . 94 



5. r. Bacterized peat . . . . . . 91 



6. ,, 6. Lime ........ 90 



7. 5. No manure ....... 83 



Comparing now those which received no artificial watering, we 

 find the following order : — 



1. Plot 10. Farmyard manure . . . . . .100 



2. ,, 9. Nothing ....... 98 



3. ,, 8. Bacterized peat . . . . . -97 



In both groups the farmyard manure plots had the heaviest plants, 

 and where bacterized peat was used in conjunction with water it had 

 a good effect, but not so great an effect as farmyard manure, especially 

 when assisted by artificials ; when used alone (without artificial water) 

 it actually reduced the yield. In conjunction with lime and watering 

 the yield was about equal to that given by farmyard manure and peat 

 in conjunction with farmyard manure. 



The greatest average weight of roots was given by the peat in 

 conjunction with lime ; next came farmyard manure, farmyard manure 

 in conjunction with artificials, and farmyard manure in conjunction 

 with peat ; the other plots followed in the order, lime alone, bacterized 

 peat alone, no manure being last. Where no artificial watering was 

 resorted to, farmyard manure was first, no manure next, bacterized 

 peat last. 



There was less difference between the weights of roots on the 

 different plots than between the total weights, which points to the 

 fact that the greatest difference was in the weight of foliage. On the 

 no manure plot, the weight of root to foliage was as 100 : 46 ; whereas 

 on Plot 4, which gave the heaviest plants, it was as 100 : 59. On the 

 whole the stimulating effect of the manures (except the lime) was seen 

 in the foliage rather than in the roots. 



The question whether the extra water given on certain plots in- 

 creased the yield is conclusively answered by the following figures : — 



Manure used. 



Average Weight. 



Not watered 

 artificially. 



Watered 

 artificially. 



Difference. 





Lb. 



Lb. 



Lb. 



Farmyard manure 



•92 



I-02 



4--IO 



Bacterized peat .... 



•85 



•97 



+ •12 



No manure .... 



•90 



•89 



— -OI 



Whereas the watering where no manure was added made no differ- 

 ence, where farmyard manure was used and where peat was used the 

 water apparently assisted in setting free some substance which the 

 plants could make use of. Where no water was used peat had no 

 stimulating effect. 



