Liebig's law and plant productivity

What is it? 

It is the limiting element that determines productivity.
This is the essence of the Liebig's law, also known as the principle of minimum and is a fundamental concept in agricultural science and ecology.

It is named after the German chemist Justus von Liebig, who first formulated it in 1840.

Liebig (1803-1973) is considered one of the founders of organic chemistry and one of the innovators of agricultural chemistry.

What does it say?

He was the first to analyze the composition of the dry matter of plants and to identify what elements it is made of.

Liebig's law states that the yield of plants is limited by the nutrient present in lesser quantity compared to the needs of the plant itself.

In other words, the factor that is in lesser quantity compared to the demand determines the growth and productivity of a particular crop.

For example, if a plant needs nitrogen, phosphorus, and potassium to grow and produce fruit, but nitrogen is present in lesser quantity, then it will be nitrogen that limits the growth and productivity of the plant.

Even if other nutrients are present in sufficient quantities, the lack of nitrogen prevents the plant from fully utilizing its growth potential.

Liebig's law has important practical implications for agriculture.

To achieve a good yield of crops, it is necessary to provide all the essential nutrients that plants need.

Furthermore, it is important to maintain a balance between nutrients to avoid deficiencies that could limit plant productivity.

Has the evolution of agricultural techniques affected this law?

When crops were only grown in open fields, the limiting factors considered were essentially only chemical nutrients and water.

Whether they were missing or not available to plants for various reasons.

Now with the advent of protected crops, indoor cultivation, and even more with controlled environment agriculture (CEA), the parameters we can control are many more and hence we can more precisely identify the "limiting deficient factor".

However, it can also come from other sources: temperature, quantity and quality of light, carbon or CO2, oxygen (in the roots!).

Identifying and properly managing the limiting deficient factor allows for the efficient management of the entire production system and therefore reduces waste.

And thus... increasing the sustainability of the production system!

Matteo Castioni