90 



EFFECT OF RAINFALL 



The figures for the centre at Wendens are perhaps the most striking, 

 the hay crop on the untreated plot varying from 51 cwts. to 14 cwts. 

 per acre. Similar, although not quite so marked, fluctuations occur 

 at all the other centres. The yearly rainfall figures afford no adequate 

 explanation of these differences. At Wendens, for example, the rain- 

 fall for the year was 27-33 inches in 1917, and in 1918 when a bigger 

 yield of hay was obtained, 25-68 inches. The distribution of the 

 rainfall, however, seems to be of great importance, particularly during 



40 



30 



20 



10 



I 



I 



J 



10 



12 



02468 



Inches of Rainfall, May.l till Harvest 



FIG. 23. Influence of Rainfall on the Yield of Hay on the Untreated Plots at 

 Tysea Hill and Martin's Hearne O. 



the months of May and June. If the rainfall figures for the period 

 May 1st till harvest are tabulated with the yield of hay on the un- 

 treated plot, as is the case in Table XLVII, it will be seen that, with 

 one or two exceptions which can be readily accounted for, there is 

 a very close connection between the two sets of figures. 



The rainfall figures have been taken from the records of the British 

 Rainfall Organisation. Their station at Havering-atte-Bower is within 

 two miles of each of the first three experimental centres. At Hasso- 

 bury there is a rainfall station on the farm, whilst at Saffron Walden 



