A pH. between 7.3 and 14 indicates an alkaline condition, the higher the pH value the greater the alkalinity. A pH below 6.5 indicates acidity and the lower the pH the greater the acidity. Most Manitoba soils have pH values from 6.8 to 7.5, which is suitable for potato production. It is required to sustain the long-term productivity of soil. Organic matter behaves as a revolving nutrient bank account, and acts as an agent to improve soil structure, maintain tilth and minimize erosion.
Organic matter releases food in a form available to plants through the process of decomposition.
To maintain organic matter, the rate of addition of crop residues must equal the rate of decomposition. Continuous production of row crops such as potatoes or sugar beets usually results in a rapid decline of soil organic matter because the total amount of crop residue returned to the soil is small. The level of organic matter in the soil can be maintained by crop rotations which include perennial forage crops, or by the production of cereal crops where residues are not removed and minimum tillage is practised. The amount varies depending on the texture and drainage of the soil, the natural vegetation under which the soil was developed, past management and erosion. Soil Compaction - All heavy equipment, including trailers for hauling potatoes, and excessive tillage can cause soil compaction.