Secondly, the soils are young and have undergone minimal weathering and leaching. Thirdly, crop removal has been relatively minor where cereals have been the dominant crop, especially where straw was left on the field or manure returned to it. There are an estimated 3 million acres of potassium deficient soils in Alberta. Of this total, about 2.5 million are moderately deficient and 0.5 million very deficient . Potassium deficient soils tend to be light to medium textured, alkaline, carbonated and imperfectly to poorly drained in their natural state.
Organic soils are also frequently deficient in potassium.
It is a relatively inexpensive nutrient, and deficiencies can often be corrected with moderate rates of application. As a result, correcting a potassium deficiency can result in excellent economic returns. The potassium content of the above-ground portion of commonly grown crops is shown in Table 1. Note the distribution of potassium between grain and straw as compared to nitrogen and phosphorus. Potassium removal from the soil is relatively low when only the grain of cereals is removed from the field.