Phosphorus (P) and Zinc (zn) Nutrition Constraints: A Perspective of Linking Soil Application with Plant Regulations

Plant nutrients availability in soils has always been a factor determining crop growth and development. The availability of plant nutrients becomes limited either due to the indigenous low fertility status of soils or the nature of parent material along with the antagonistic chemical interactions. Phosphorus (P) is an essential macronutrient, while zinc (Zn) is a vital micronutrient for crop growth and development in any agricultural production system. However, their co-existence remains a challenge in acidic as well as alkaline calcareous soils, worldwide. For instance, P precipitates as calcium phosphate (Ca3(PO4)2) in calcareous soils at high pH, whereas the precipitation of both P and Zn occurs as zinc phosphate (Zn3(PO4)2) in both alkaline calcareous soils (submerged conditions) and acidic soils owing to low pH conditions. This scenario renders limitations of both these essential nutrients in most of the agricultural soils. Various strategies like integrated nutrient management (INM), enhanced soil organic matter (SOM) incorporation and increased chemical fertilizer applications have been implied to make P and Zn available for crop uptake. Chemical (Inorganic) fertilizer application ensures P and Zn availability during the critical growth stages of plants; however, it results more in fixation rather than their availability. Thus, there is a need to consider the overall P and Zn dynamics in the soil and plant system by exploring their availability, transformation and utilization through soil, rhizosphere and plant processes. In this review, we will discuss the progress in P and Zn transporters/regulators in plants with a potential perspective of their linkage with the practices of P and Zn soil application rates to cope their coexistence constraints in agricultural soils.