264 The Wohurn Pot-Culture Experiments, 1906-7. 
Rainfall at Woburn Experimental Station, 1907. 
(292 ft. above sea level.) 
1907 
lu. 
January . . . . I -04 
February .... 0‘99 
March .... 0’83 
April 2'20 
May . . . . 3-48 
June I ‘67 
1907 
In. 
July 1-86 
August . . . P84 
September. . . . O' 64 
October .... 3'74 
November .... 1'84 
December .... 3'66 
Total . . 23-78 
POT-CULTURE EXPERIMENTS, 1906-7 
(summary). 
It being the intention to issue shortly, in separate form, a 
detailed account of the Pot-culture Experiments which have 
been carried on for some years past, these are not dealt with at 
any length in the present report. But it is thought well to 
indicate briefly their present scope and certain points of 
interest arising out of them. 
In the first place, the work in connection with the Hills’ 
Experiments has been continued, the influence of salts of 
lithium, in particular, being investigated. The presence of as 
little lithium, in the form of the chloride or the sulphate, 
as to show -05 of the metal in 100 parts of soil, is found to 
reduce the yield of wheat to one-quarter of the natural, 
untreated crop. On the other hand, the presence of sulphate 
of iron to this same extent increased the produce materially. 
The detrimental action of lithium salts was found to he largely 
due to the stunting of root gi’owth. 
The chloride and sulphate of manganese have also been 
shown to have a beneficial effect upon the oat crop, when given 
in quantities not exceeding 1 cwt. per acre. 
Further work has been done on the subject of green 
manuring, and the results of the Field Experiments in 
Lansome Field (in which tares ploughed in have always given 
a subsequent corn crop inferior to that when mustard has been 
ploughed in) have been explained at the Pot-culture Station by 
the alteration produced in the physical condition of the soil. 
When tares are grown the soil is left in a light and very open 
condition, and there is much more rapid loss of moisture than 
when mustard is grown ; the soil, being left in a less consoli- 
dated condition and requiring more moisture to be supplied to 
it, is, in the case of a light sandy land, such as that of Woburn, 
in a much less suitable condition for the subsequent growth of 
a wheat crop after tares have been grown and ploughed in. 
