SECTION M.—AGRICULTURE. 277 
however, so brilliantly led in this country by Sir John Russell and his 
colleagues, leaves us with no excuse for such restricted conceptions 
of soil fertility, which must now be regarded as the index of the 
equilibrium established by the mutual interactions of a highly complex 
series of factors, the variation of any one of which may affect the 
interplay of the whole, with consequent effect upon the rate or character 
of plant growth. 
The problem of fertility being so complex, one might perhaps be 
inclined to despair of attaining to anything really effective in soil 
advisory work, which must necessarily be dependent upon rapid and 
somewhat superficial examination, and such apparently is the view 
held by the Ministry of Agriculture if one may judge by the con- 
spicuous neglect of chemical and physical science in recent extensions 
of advisory facilities. 
My own conception, however, of the present possibilities of soil 
advisory work is more optimistic, and from experience covering the 
most diverse parts of the country I am confident that an extension of 
facilities for soil advisory work would be of immediate and progressively 
increasing benefit to the farmer. 
It is the common experience of all engaged in soil advisory work 
that, although what may be termed the ‘average soil’ offers great 
difficulties, there are many soils in all parts of the country which are 
distinctly not ‘ average’ for the areas in which they are situate, and 
for which our converitional methods of chemical and mechanical 
analysis, crude though they be, and imperfect the premises upon which 
their interpretation is based, do yield guidance which on application in 
practice proves to have been substantially sound. The real difficulty 
at the moment is that for large tracts of the country we lack the neces- 
sary data to enable us to determine what is the ‘ average soil’ for each 
particular area, and until provision is made for specific soil work in 
these areas, which comprise the whole of the great agricultural areas 
of the Midlands, our advisory work relating to this raw material of 
crop production must of necessity remain superficial, and only too 
frequently ineffective. 
In no direction has the need for extended soil advisory work become 
more evident in recent years than in the revelation of the extent to 
which large areas of our soils have become depleted of lime. Cases 
come almost daily to our notice in which this lack of lime is clearly 
the chemical ‘ limiting factor,’ and the annual waste due to unremunera- 
tive expenditure on fertilisers on such land must indeed be very great. 
In many cases, fortunately, the depletion has been detected at a stage 
at which it is still economically remediable, but in others, unfortunately, 
this is no longer the case, and unless soil-survey facilities be greatly 
extended it is certain that large areas of our land must steadily fall into 
the latter category, with the inevitable development in the near future 
of a problem of such magnitude as will require national action for its 
solution. It is worthy of note also in passing that this problem will 
probably be accentuated rather than diminished as a greater proportion 
of our arable land reverts to grass. 
A further direction in which great scope remains for the work of 
