Variations in Soil Reaction Affect Nitrification

In some of the earliest studies on nitrification, it was found that the reaction of the soil exerted a profound influence on the occurrence of the process. In strongly acid soils, frequently no nitrate formation took place, and as the acidity increased, the process proceeded more and more slowly. It was further noted that additions of lime to acid soils would stimulate the action of the nitrifying bacteria and a greater production of nitrates would occur