Phosphorus is the second most important crop nutrient after Nitrogen. It is an essential macronutrient that plays important role in all crop biochemical processes such as photosynthesis, respiration, energy storage, transfer, cell division, cell enlargement and nitrogen fixation. It is also important in seed germination, seedling establishment, root, shoot, flower and seed development. Despite its importance in crop nutrition, availability of the nutrient in soils for plant uptake is limited by several soil factors. The factors include: soil pH levels, clay mineralogy, organic matter, free iron and aluminium, calcium carbonate, soil temperatures and availability of other nutrients among other factors. Availability of phosphorus for plant uptake can be managed by adoption of practices such as liming acidic soils, application of organic amendments in both alkaline and acidic soils, tillage practices and regulation of time and method of P fertilizer application.
The importance of phosphorus to crops
Phosphorus (P) takes its rightful place alongside Nitrogen and Potassium among the three primary macronutrients essential to successful plant growth. Without Phosphorus, photosynthesis could not occur. Phosphorus plays a key role in complex energy transformations that are necessary to all life, as a main ingredient in ATP (adenosine triphosphate). It is also a central component of DNA and RNA – and is necessary for building proteins and other compounds. That is just the beginning. Phosphorus is required by the plant from the seedling stage through to maturity – and has a measurable impact on crop quality and yield.
Identifying phosphorus deficiency
As you can see, the importance of phosphorus to crops cannot be understated. It explains why a Phosphorus deficiency can have a devastating impact on crop quality and yield. Plants suffering from phosphorus deficiency show several telltale signs: such as stunted growth and fibre colours ranging from dark green to reddish purple (caused by the accumulation of sugars). Phosphorus deficiencies later in the growing season will negatively affect seed and fruit development, as well as crop maturity. As the chart below demonstrates, the majority of tests indicate low or very low Phosphorus levels across the prairie provinces, based on a fairly substantial sampling size.