The replacement of calcium lost from the soil by leaching and crop uptake is essential to maximise production and profits from cereal crops.
The growth of cereals of high protein content depends on stability of pH during the growing cycle; barley is an example where sensitivity to soil pH is particularly apparent. Sugar beet also takes up nutrients most effectively in soils with a pH 6.5-7.0. Increasing acidity results in stunted plants and fangy roots.
The crop requirements diagram provides a guide to the optimum pH levels for some important crops. If soil pH is lower than the bottom of the indicated range, then crop yields will begin to suffer severely due to the crops' inability to tolerate that level of acidity. Those crops which are tolerant to acidity would be more profitable at higher pH values. At a pH of 4.9 one is not getting as good a response from the fertilisers applied to maximise the potato crop as at the optimum pH. Lime also aids soil fertility in grassland and ensures that added fertilisers are utilised to maximum effectiveness and helps to increase crop yield either as hay, silage, or grazing. It is particularly important to adjust soil pH well in advance for sensitive crops such as oilseed rape, sugar beet, barley and peas. Spreading should be even, accurate, and cause little disruption to the soil structure.