Besides nitrogen, phosphorus is one of the most critical essential elements for adequate crop growth and productivity in agricultural ecosystems.
Phosphorus is involved in the synthesis of several essential compounds required for plant growth and functioning. These compounds include adenosine triphosphate (ATP); the energy currency of the cell, containing a high-energy phosphate group that helps in the storage, transport, and exchange of energy in the biological systems. They also include deoxyribonucleic acid (DNA), which is the driver of genetic inheritance, and ribonucleic acid (RNA), which regulates protein synthesis.
Availability of phosphorus promotes multiple aspects of plant growth. These include photosynthesis, flowering, seed production, and root growth including nodule formation and nitrogen fixation in leguminous plants
Additionally, phosphorus also helps to prevent lodging in cereal crops by strengthening the structural tissues of the stalk. Phosphorus deficiency leads to stunted, and thin-stemmed plants. However, phosphorus deficiency may be less noticeable compared to other nutrient deficiencies. This is due to many cases having a lack of symptoms on foliage.
Phosphorus is very mobile within the plant, meaning phosphorus from older leaves is transferred to the younger, rapidly growing leaves. Thus, the older leaves may show deficiency symptoms such as premature senescence, yellowing, and purpling in some cases
Phosphorus deficiency may also cause delayed maturity, poor flowering, and low seed quality in the crops.
The following articles in this series will discuss different forms of plant-available phosphorus in soils, challenges associated with phosphorus fixation, and impacts of environmental quality.