PURDUE UNIVERSITY
Agricultural Experiment Station
Circular No. 33
LaFayette, Ind., February, 1912
LIMING THE SOIL
John B. Abbott Department of Soils and Crops
Producers of lime and ground limestone are practically unanimous in saying that the use of these materials for agricultural purposes is increasing very rapidly. One reply to a circular letter of inquiry which was sent to producers stated that the business of the past year exceeded the combined totals of the three years preceding and every other reply, except one, noted a marked increase in consumption, particularly within the past year. This rapid increase in the use of agricultural lime is undoubtedly quite largely due to the awakening of interest in alfalfa culture, and the general acceptance of the teaching that nearly all land in Indiana, except limestone land showing outcrops of stone, must be limed before this valuable crop can be most successfully grown.
Many of the inquiries received by the Experiment Station relative to the vise of lime on the soil are so vague in character as to lead us to believe that in many cases lime is being used without a clear understanding of its effect on the soil, or of when it should be used and when it should not. In view of the sometimes extravagant claims for its good effect, and the equally extravagant warnings as to the dangers in its use, it seems probable that some farmers are using lime where it is totally unnecessary and sustaining a financial loss thereby, while others fear to use it where it is really needed, thereby failing to reap a possible profit. For these reasons this circular of general information on the lime question is offered at this time.
THE CHEMISTRY OF LIME COMPOUNDS
There are two classes of chemical compounds, acids and bases, which have the power to destroy or neutralize the characteristic properties of each other. Lime is a basic or alkaline material, and is applied to the soil primarily for the sake of neutralizing harmful