Importance of Micronutrients in Agriculture

Micronutrients play a vital role in plant growth and development even though they are required in small amounts. Lack of essential micronutrients in soil can significantly reduce crop yields.

What are Micronutrients?

Micronutrients, also known as trace elements, are chemical elements required by plants and animals in tiny amounts. They include zinc, copper, iron, manganese, boron, molybdenum, chlorine and nickel. While macronutrients like nitrogen, phosphorus and potassium are needed in relatively large quantities, micronutrients are typically needed in amounts measured in parts per million in the plant tissue. Even though required in small amounts, micronutrients are just as essential as macronutrients for plant growth and metabolism.

Key Roles of Micronutrients

Agricultural Micronutrients play vital roles in many plant processes like photosynthesis, nitrogen fixation, sugar and starch production, enzyme activation etc. Zinc is important for protein synthesis and starch production. Copper aids in iron absorption and is essential for chlorophyll formation. Manganese assists in enzyme activation, nitrogen and carbohydrate metabolism. Iron aids in chlorophyll formation and is part of enzyme systems involved in nitrogen fixation. Boron is important for cell wall formation, sugar translocation, nitrogen and calcium metabolism. Molybdenum aids in nitrogen fixation and enzymatic reactions.

Absence of even one essential micronutrient can negatively impact crop yield and quality significantly. For example, zinc deficiency reduces crop yields by 10-15% worldwide. Iron deficiency leads to yellowing and stunted growth in many plants. Boron deficiency causes hollow stems and cracked leaves in fruits, vegetables and ornamental plants.

Micronutrient Deficiency – A Common Problem

Micronutrient deficiency is a widespread problem affecting crops globally due to various reasons like intensive cultivation, soil erosion, leaching, imbalance use of fertilizers etc. Continuous mono-cropping, intensive use of high analysis fertilizers devoid of micronutrients, imbalanced or excessive use of fertilizers can deplete micronutrients from soil over time. Sandy and acidic soils are prone to leaching of micronutrients. Alkaline and saline soils shows fixation of micronutrients making them unavailable to plants.

Micronutrient Management Strategies

Proper micronutrient management includes soil testing to determine deficiencies and balanced application of fertilizers containing micronutrients. Some key strategies used by farmers are:

– Application of micronutrient fertilizers or fertilizers mixed with micronutrients as foliar sprays or soil application. Commonly used fertilizers are zinc sulfate, copper sulfate, iron chelate etc.

– Use of micronutrient mixtures or multimicronutrient fertilizers catering to multiple deficiencies.

– Application of organic manures like compost, farmyard manure which help improve soil micronutrient status.

– Green manuring with leguminous crops which fix micronutrients in soil through roots and leaves.

– Crop rotation with legumes which solubilize micronutrients making them plant-available.

– Use of micronutrient rich vermicompost or other biofertilizers.

– For problem soils prone to fixation, application of chelated micronutrient formulations which remain available for longer duration.

– Maintaining proper soil pH for optimum availability of different micronutrients.

Proper identification of deficiency through soil and plant tissue testing and balanced micronutrient management is key to boost agricultural productivity on a sustainable basis. With increasing demand for food, judicious use of all essential nutrients including micronutrients assumes great significance.

Significance of Some Major Micronutrients

– Zinc
Zinc plays a key role in many enzyme systems, protein synthesis and helps in carbohydrate metabolism. Deficiency of zinc leads to stunted growth, rosetting of leaves and dieback of terminal portions in crops. It is required by most field crops, fruits, vegetables and ornamental plants.

– Iron
Iron is essential component of electron transfer mechanisms in plants and is part of enzyme systems like nitrogenase. Iron deficiency leads to interveinal chlorosis in younger leaves. It affects a wide range of crops including paddy, wheat, maize, fruits, vegetables etc.

– Copper
Copper aids in chlorophyll formation, iron transport and carbohydrate metabolism. Copper deficiency causes dieback of young shoots and leaves turning bleached. It impacts apple, pear, citrus, arabica coffee, cotton, chilli, potato crops.

– Manganese
Manganese is required for activation of various enzymes in photosynthesis and respiration. Deficiency results in interveinal chlorosis between veins starting from younger leaves. It affects paddy, maize, soybean, pulses, banana etc.

– Boron
Boron is essential for cell division and cell wall synthesis. Deficiency causes stunted growth, cracked stems, hollow stems, cracked leaves and flowering/fruiting issues. It is particularly important for most fruits and vegetables.

Proper management of these essential micronutrients helps boost yields and crop quality in a sustainable manner. Integrated soil-plant testing and balanced fertilization go a long way in ensuring micronutrient sufficiency for agricultural crops.

Micronutrients play a vital supportive role along with macronutrients in ensuring optimum plant growth. Though required in small quantities, deficiency of any one micronutrient can negatively impact crop productivity. Continuous intensive cropping patterns without micronutrient replenishment deplete soil micronutrient levels over time. Judicious application of micronutrient fertilizers tailored to cropping system, soil conditions along with organic manures help maintain adequate micronutrient status in soil. Along with macronutrients, achieving sufficiency of all essential micronutrients through integrated nutrient management holds the key to boosting agricultural productivity on a sustained basis.

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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it