THE 
AGRK^OLTURAL fflAGA 
COLOMBO. 
Added as a Supplement Monthly to the " TBOI'ICAL AGlilCULTUFJST." 
The following pages include ihe Contents of the AgricuUural Magazine for 
March :— 
Vol. XIII.] 
MARCH, 1902. 
[No. 9. 
VALUE OF SOIL ANALYSIS. 
''E have beeu much struck by the 
blind faith which people place in 
soil analysis, relying upon if: ns a 
mysterious " open sesame " to the 
secrets of Nature as she works 
through plant and soil. The fact is that the old 
method of soil analysis as it is ordinarily under- 
stood by laymen has come to be discredited long 
ago since. 
If we consider for a moment what a soil 
analysis is generally expected to tell us, we shall 
see how presumptive are the claims of the 
chemist who takes credit for being able to give us 
this information by his manipulations in the 
laboratory. 
How is it supposed that the chemist can 
recognise the subtle relation between the vital 
forces in the plant and the soil in carrying out 
his analyses, with a view to telling you what has 
to be added to the soil to meet the requirements 
of the plant ? Does he make allowance for the 
capacity in plants to attack and appropriate the 
ingredients of plant food in the different forms in 
•which they occur in the soil, and for the differ- 
ences in his capacity in different plants? Tiie 
sdlvent medium adopted in reckoning the propor- 
tion of " available " plant food in the soil has 
always been an nncertaiu factor in soil analysis, 
which has shifted its ground more than once 
with a view to reaching more accurate results. 
The recognised action and interference of soil 
bacteria in the preparation of plant food has only 
helped to further complicate the difflcuUies of the 
agricultural chemist and the uncertainty of 
chemical analysis as a gauge of the fertility of soils. 
The "outside influences ' in the preparation and 
appropriation of plant food in the soil are so 
important that the mere treatment of soil by purely 
chemical methods gives very imperfect and 
runeliable results. Indeed the biologicil action 
that takes place in the soil has come to be 
admitted to be as important, if not more import 
tant, than the chemical. So that the analytica, 
chemist, if he is to give us accurate information 
as regards the fertility of our soils and the 
requirements of plants growing in them, must 
widen his scope of operations to a considerable 
extent, and tot he best of his ability, take cogni- 
sance of the vital action exercised by the plant and 
thebncterial activity within thesoil — forces, itmust 
be admitted, that cati hardly be estimated at their 
fall value in the laboratory. It would seem- 
therefore, that apart from his purely technical 
qualifications in science as a chemist would need to 
have a considerable practical experience of soils 
and manures, and a large endowment of common 
sense — on which indeed he has to rely to a great 
extent in drawing his conclusions as to the 
properties and requirements of particular soils. 
AVe were only last week discussing this subjeet 
with an eminent agricultural authority who 
passed through the Island on his way to take up 
an important appointment in the Antipodes, and 
were much impressed with his strong condem- 
nation of the reliance placed by some on the 
results of chemical analyses. Such people tliink 
it is enough for them to send a sample of soil to 
a chemist with a note saying, " Please analyse 
the accompanying sample and, let me know what 
