Lime

​Farmers use lime to provide the soil with magnesium and calcium.  It also has the benefit of increasing pore space in the soil and increasing pH levels.  Liming is potentially a risk to the soil if over time, too much lime is added, thus the soil will become more alkaline.  Also over liming can cause issues with trace elements.  For example, too much calcium in the soil will make it more likely that trace elements will be tied up in the soil and instead of being available to plants.