Plant NutritionEdit

Plant nutrition is the study of how plants acquire and use the chemical elements they need to grow, reproduce, and carry out essential metabolic processes. Although plants obtain much of their carbon, hydrogen, and oxygen from air and water, the elements that make up proteins, nucleic acids, chlorophyll, enzymes, and cellular structures must be supplied from the soil or other growing media in which the plant resides. The balance and availability of these nutrients influence not only plant size and yield but also the quality of crops and their resilience to stress. In modern agriculture, understanding plant nutrition supports productive farming while informing practices that protect soils, ecosystems, and water quality. nutrient soil photosynthesis fertilizer

Essential elements

Plants require a defined set of essential elements. They are commonly grouped into macronutrients, which are needed in larger amounts, and micronutrients, required in smaller quantities but still vital for growth and development.

Macronutrients

nitrogen: a key component of amino acids, nucleic acids, and chlorophyll; its availability often limits growth in many systems. It is supplied as ammonium or nitrate in soils and fertilizers. nitrogen
phosphorus: involved in energy transfer (ATP) and genetic material; often applied as phosphate fertilizers. phosphorus
potassium: supports enzyme activity, osmoregulation, and stomatal function; influences yield and quality. potassium
calcium: important for cell walls and signaling; supports root and shoot growth. calcium
magnesium: central atom in chlorophyll and a cofactor for enzymes. magnesium
sulfur: a component of some amino acids and vitamins; supports protein synthesis. sulfur
carbon, hydrogen, and oxygen: derived largely from carbon dioxide in the air and from water; these are foundational elements of carbohydrates, lipids, proteins, and nucleic acids and are not typically added via the soil as primary nutrients. carbon hydrogen oxygen

Micronutrients

iron, manganese, zinc, copper: essential cofactors in photosynthesis, respiration, and other enzyme systems. iron manganese zinc copper
boron: important for cell wall formation and reproductive development. boron
molybdenum: a cofactor for enzymes involved in nitrogen metabolism. molybdenum
chlorine: plays a role in osmosis and photosynthesis in some contexts. chlorine
nickel: required in very small amounts for certain enzymes in some plants. nickel

Plants absorb these elements from growing media through roots, and the uptake is influenced by soil chemistry, pH, moisture, and microbial activity. For many nutrients, availability depends on soil properties such as texture, organic matter, cation exchange capacity, and the balance between positively charged ions and soil solution. The dynamics of nutrient supply and uptake are often studied through concepts like nutrient availability and nutrient use efficiency. soil organic matter cation exchange capacity nutrient availability nutrient use efficiency

Uptake and transport

Nutrients move from the growing medium into roots by diffusion, mass flow with water movement, and, for some nutrients, active transport powered by energy. Once inside the plant, minerals travel through the xylem to above-ground tissues, or, in some cases, via the phloem as part of ongoing redistribution. Root hairs and associations with soil microorganisms can dramatically increase the effective surface area for uptake; mycorrhizal fungi, for example, extend the root system and enhance access to sparingly soluble nutrients. root hair mycorrhiza xylem phloem diffusion mass flow active transport

The rhizosphere—the zone of soil surrounding roots—hosts complex chemical exchanges. Root exudates can alter microbial communities, influence nutrient solubility, and affect nutrient cycling. Soil pH, redox conditions, and the presence of competing ions all shape which nutrients are available and in what form. rhizosphere soil pH nutrient availability redox soil microbial communities

Sources and management

Nutrients come from the growing medium, soil mineral reserves, decomposed organic matter, and manufactured fertilizers. In managed systems, agronomic practices aim to match nutrient supply with plant demand while minimizing losses to leaching, volatilization, runoff, or erosion. Practices include soil testing and precision management, timing and placement of fertilizers, and the use of controlled-release formulations. In hydroponic and other soilless systems, nutrients are supplied in carefully balanced solutions to maximize growth and efficiency. fertilizer soil testing precision agriculture hydroponics soil health nutrient management

Soil chemistry greatly influences nutrient availability. For example, pH affects the charge and solubility of many nutrients, with different crops requiring distinct optimal ranges. Liming can adjust pH and, in turn, affect nutrient availability and microbial activity. Organic matter contributes to nutrient storage, cation exchange capacity, and overall soil resilience, while mineral weathering progressively releases nutrients over time. pH liming organic matter mineral weathering

Nutrient management also encompasses environmental considerations. Excess fertilizer use can contribute to surface and groundwater pollution, including eutrophication in water bodies and downstream ecological impacts. As a result, modern systems emphasize nutrient use efficiency, balanced fertilization, and practices that reduce losses while maintaining yields. environmental impact nutrient use efficiency eutrophication

Role in agriculture and ecosystems

Plant nutrition underpins agricultural productivity, crop quality, and food security. Efficient nutrient management supports higher yields with lower resource input, aligns with sustainable farming goals, and helps maintain soil health across generations. It also intersects with broader topics like plant breeding for nutrient efficiency and the development of nutrient-rich crops through approaches such as biofortification. agriculture crop yield soil health biofortification plant breeding

The science of plant nutrition integrates with related disciplines, including soil science, agronomy, horticulture, and environmental science. It informs policies and practices around fertilizer use, soil conservation, and water quality, while continuing to evolve with advances in plant physiology and microbial ecology. soil science agronomy horticulture environmental science