Diagnosing the micronutrient deficiencies in crops can help identify the challenges that occur during their growth. By learning more about the symptoms of these deficiencies, one can give the right micronutrient treatment to the plants and manage the deficiencies effectively.

Micronutrients play a vital role in the growth and development of plants. The productivity of plants can decline without these nutrients. The eight micronutrients out of 17 elements that are essential for plant growth are boron (B), chlorine (CI), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn) and nickel (Ni). The deficiency of some of these micronutrients can lead to symptoms mentioned below: 

1. Nitrogen Deficiency

The deficiency of nitrogen in plants can cause pale, yellowish-green corn plants with spindly stalks. This is because nitrogen is a mobile nutrient in the plant so symptoms begin to show on the older leaves and progress up the plant with persisting deficiency. The symptoms become visible on leaves as they start yellowing from the tip and progress down the midrib toward the leaf base. The condition of the plants becomes even worse with:

• Cold or saturated soil, particularly dry soil after mid-season.

• Large amounts of low-nitrogen residue.

• Sandy soil.

• Inadequate fertilizations.

• Leaching from heavy rainfall.

• Flooded or ponded soil when the temperature is warm.

2. Potassium Deficiency 

Yellowing and necrosis of leaf margins are observed on the lower leaves if they have potassium deficiency. These symptoms appear sometime after planting, which is about 4 to 6 weeks i.e., the V6 growth stage. If the deficiency persists for a long time the symptoms start showing up in the plants. This is because potassium is a mobile nutrient that translocate from older to younger leaves. When potassium deficiency gets severe, the older leaves turn yellow and get tissue necrosis along the margins and the new leaves may remain green. 

A potassium-deficient plant lodges late in the growing season due to poor stalk strength. It is favored by conditions limiting early root growth, development, and activity pruning, compacted soil, dry soil, seed trench, side-wall smearing, wet soil, organic soil, sandy soil, strongly geologically weathered soils, potassium put in where plant roots cannot absorb it, large amounts of potassium drawn out by a preceding crop, and tillage systems like ridge-tillage and no-tillage.

3. Phosphorus Deficiency

The symptoms of phosphorous deficiency are seen in young plants. The plants are dark green in color with red-purple leaf tips and margins on old leaves. If a plant has phosphorus deficiency, the newly emerging leaves will not show any coloration. These plants are small and grow even slower than plants which have adequate phosphorus. The symptoms of deficiency disappear whenever the plants grow three feet or taller. Phosphorus deficiency is favored by phosphorus when applied where plant roots are unable to absorb it, cold soils that may be too wet or too dry, restricted root growth in tight soils, and roots damaged by impure fertilizers, insects, herbicides, or cultivation.

Many factors can affect the availability of micronutrients. One of them is organic matter, when soils have low levels of organic matter for example grey soils can be deficient in micronutrients. Some of the other factors include soil texture and pH levels. So, if one wants to know about the micronutrient deficiencies in soil, be vigilant of such factors and improve the growth of the crops with the help of growth enhancement supplements.