CONSIDER THE SOIL 
9 
ture. The depth of a mulch varies with the climatic conditions to 
be met. Yet, since it must be perfectly dry to be effective, usually 
the deeper it is, the greater will be its usefulness. In arid regions, 
mulching has been found to be most successful, although it is 
questioned whether mulches other than dry soil are advisable where 
the pill-bugs or sow-bugs are prevalent as it will afford a harbor 
for them. 
II. CHEMICAL CONSTITUENTS 
CHEMICAL ANALYSIS 
No type of soil contains sufficient nourishment to continue to 
sustain a large group of plants. Therefore, additional nutriment 
must be supplied, for plants demand quantities of nitrogen, phos¬ 
phorus and potash for perfection of development. 
Nitrogen: 
Nitrogen is needed to produce color and brilliance in fruit 
and flowers, as well as aid in developing leaf and stem-growth, 
being taken up by the plant in its early stages of growth. Cotton¬ 
seed meal, dried blood, nitrate of soda and sulphate of ammonia 
help to supply sufficient nitrogen to plants. 
Phosphorus: 
Phosphorus (or phosphoric acid) supplies those qualities that 
assist in the maturing of seed, in the development of root-growth 
and in perfection of flower, giving to the plants power to counter¬ 
act that weakening tendency toward contracting disease which is 
caused by nitrogen, and being absorbed by the plants about uni¬ 
formly during the period of their active growth. Its natural source 
is to be formed in bonemeal and the other mineral phosphates. 
Potash: 
Potash helps phosphoric acid in making plants disease-resistant 
and supplies that which bring them to normal maturity, produc¬ 
ing larger, more vigorous plants. It can be supplied by hardwood 
