Role of Plant Nutrients in Plant Growth and Physiology

TLDR: In this article, the main functions of the mineral nutrients that have a bearing on the quantitative and qualitative aspects of crop productivity are discussed, focusing on the main function of the micronutrients in terms of cell osmotic relations and turgor-related processes.

Abstract: A mineral element is considered as essential based on the criteria of essentiality given by Arnon (Criteria of essentiality of inorganic micronutrients for plants. In: Wallace T Trace elements and plant physiology. Chronica Botanica, Waltham, pp 31–39, 1954), according to which 16 elements known as mineral nutrients are required for completion of a productive life cycle in plants. These mineral nutrients are carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, iron, manganese, zinc, copper, boron, molybdenum and chlorine. Of these C and at times S are taken up from air as CO2 and SO2, and oxygen and hydrogen are provided as water. The soil is the source for uptake of the other elements by plants. Based on their requirement, these nutrients have been classified as macronutrients (N, P, K, Ca, Mg and S) because they are required at concentrations higher than 1–150 g per kg of plant dry matter and micronutrients (Fe, Zn, Mn, Cu, B, Mo and Cl) which are required at concentration of 0.1–100 mg per kg of plant dry matter. However their requirement per se does not alter their significance for the plant growth and metabolism. The mineral nutrient elements play essential roles such as constituent of cell structures and cell metabolites, in cell osmotic relations and turgor-related processes, energy transfer reactions, enzyme-catalysed reactions and plant reproduction. Plant productivity depends on the efficient discharge of these functions. In this chapter we focus on the main functions of the mineral nutrients that have a bearing on the quantitative and qualitative aspects of crop productivity.