Others may be in low concentrations. This is why we add fertilisers to sandy soils in spring, just before we plant or when the new growth is occurring. Of course, any lack of nutrients will have an effect on your plants, leading to reduced vigour, smaller flowers and lower yield on edible crops. It is of great importance that correct feeding is carried out. Generally, the addition of well-rotted organic material once a year is plenty and only supplementary feeding of inorganic fertilisers is needed if you are growing show plants.
There is a small warning though, overfeeding can be just as damaging as underfeeding. Too much Nitrogen in the soil will lead to “leggy” and soft growth in herbaceous plants leaving them vulnerable to collapsing and insect attacks.
The pH scale is how we measure how acid or alkaline a substance is, including soils. It ranges from 1 (very acidic) to 14 (very alkaline) and 7 being neutral. From neutral, a rise of one on the scale to 8 means that the soil is 10 times more alkaline. A drop of one from neutral means it is 10 times more acidic. Generally, UK soils range from 4.5 to 8.
pH has a large effect on the ability of the plant to take nutrients from the soil. Alkaline soils mean iron and manganese are difficult for the plant to take up. This can cause a disorder called lime induced chlorosis in calcifuges, due to the lack of iron and manganese needed in the production of chlorophyll. It can be seen as yellowing in the margins of leaves with browning of the leaf edges.