> be removed or the land will become useless.



The land may be soured in several ways. Whenever a large amount of

vegetable matter decays in land, acids are formed, and at times sourness

of the soil results. Often soils sour because they are not well drained

or because, from lack of proper tillage, air cannot make its way into

the soil. Sometimes all these causes may combine to produce sourness.

Since most crops cannot thrive on very sour soil, the farmer must find

some method of making his land sweet again.



So far as we now know, liming the land is the cheapest and surest way of

overcoming the sourness. In addition to sweetening the soil by

overcoming the acids, lime aids the land in other ways: it quickens the

growth of helpful bacteria; it loosens stiff, heavy clay soils and

thereby fits them for easier tillage; it indirectly sets free the potash

and phosphoric acid so much needed by plants; and it increases the

capillarity of soils.



However, too much must not be expected of lime. Often a farmer's yield

is so increased after he has scattered lime over his fields that he

thinks that lime alone will keep his land fertile. This belief explains

the saying, "Lime enriches the father but beggars the son." The

continued use of lime without other fertilization will indeed leave poor

land for the son. Lime is just as necessary to plant growth as the

potash and nitrogen and phosphoric acid about which we hear so much, but

it cannot take the place of these plant foods. Its duty is to aid, not

to displace them.



We can tell by the taste when salads are too sour; it is more difficult

to find out whether land is sour. There are, however, some methods that

will help to determine the sourness of the soil.



In the first place, if land is unusually sour, you can determine this

fact by a simple test. Buy a pennyworth of blue litmus paper from a drug

store. Mix some of the suspected soil with a little water and bury the

litmus paper in the mixture. If the paper turns red the soil is sour.



In the second place, the leguminous crops are fond of lime. Clover and

vetch remove so much lime from the soil that they are often called lime

plants. If clover and vetch refuse to grow on land on which they

formerly flourished, it is generally, though not always, a sign that the

land needs lime.



In the third place, when water grasses and certain weeds spring up on

land, that land is usually acid, and lime will be helpful. Moreover,

fields adjoining land on which cranberries, raspberries, blackberries,

or gallberries are growing wild, may always be suspected of more or less

sourness.



Four forms of lime are used on land. These, each called by different

names, are as follows:



First, quicklime, which is also called burnt lime, caustic lime,

builders' lime, rock lime, and unslaked lime.



Second, air-slaked lime, which is also known as carbonate of lime,

agricultural lime, marl, and limestone.



Third, water-slaked, or hydrated, lime.



Fourth, land plaster, or gypsum. This form of lime is known to the

chemists as sulphate of lime. Do not forget that this last form is never

to be used on sour lands. We shall therefore not consider it further.



Air-slaked lime is simply quicklime which has taken from the air a gas

called carbon dioxide. This is the same gas that you breathe out from

your lungs.



Water-slaked lime is quicklime to which water has been added. In other

words, both of these are merely weakened forms of quicklime. One hundred

pounds of quicklime is equal in richness to 132 pounds of water-slaked

lime and to 178 pounds of air-slaked lime. These figures should be

remembered by a farmer when he is buying lime. If he can buy a fair

grade of quicklime delivered at his railway station for $5.00 a ton, he

cannot afford to pay more than $3.75 a ton for water-slaked lime, nor

more than $2.75 for air-slaked lime of equal grade. Quicklime should

always be slaked before it is applied to the soil.



As a rule lime should be spread broadcast and then harrowed or disked

thoroughly into the soil. This is best done after the ground has been

plowed. For pastures or meadows air-slaked lime is used as a

top-dressing. When air-slaked lime is used it may be spread broadcast in

the spring; the other forms should be applied in the fall or in the

early winter.