Zinc is one of the eight essential trace elements that plants need for normal growth and reproduction. Nearly 10% of all proteins in biological systems need zinc for their functions and structure. Plants require zinc in small but critical concentrations for several key actions, including: membrane function, photosynthesis, protein synthesis, phytohormone synthesis (e.g. auxine), seedling vigor, sugar formation, and defense against disease and abiotic stress factors (e.g., drought).
Even when a plant’s macronutrients of nitrogen, phosphorous, potassium, and water are met, zinc deficiency will prevent plants from reaching their full potential. And yet large swaths of agricultural land are known to be deficient in zinc, causing severe limitations in crop productivity and the nutritional value of those crops.
A study for the Food and Agricultural Organization (FAO) by Sillanpää found that zinc was the most commonly deficient micronutrient in the world. The study, which examined 190 field trials in fifteen countries, found that zinc deficiency occurred in one out of every two trials.
Today, it is estimated that 50% of agricultural soils devoted to cereal cultivation are potentially zinc deficient. Over two-thirds of the rice grown worldwide is produced on flooded paddy soils, which generally contain very low amounts of plant-available zinc. Wheat is typically grown on alkaline, calcareous soils with low organic matter in the semi-arid regions of the world. These soil and climactic conditions tend to make zinc less available for uptake and use by plants.
This high prevalence of zinc-deficient soils in major agricultural zones severely limits agricultural productivity. Under zinc-deficient soil conditions, plants show a high susceptibility to environmental stress factors such as drought, heat stress, and pathogenic infections, which in turn stimulate development of chlorosis and necrosis on the leaves and cause stunted growth.
Applying zinc fertilizers to soil and onto plant leaves offers a simple and highly effective solution to zinc deficiency problems and significantly reduces unnecessary loss of food production. It also enhances grain zinc concentration which contributes to daily zinc intake of human populations in a sustainable and environmentally responsible manner.
For a striking visualization of the impact of zinc deficiency, view the time lapse video below: