Great Bend Tribune
Published August 28, 2016
An unsettled weather pattern and a stalled cold front have led to rains and cooler temperatures. While this isn’t a general overall event, many areas have received significant and in some cases excessive rain. Great to fill sorghum heads and soybean pods while providing soil moisture for the 2017 wheat crop. The fall semester is upon Barton and a new class of freshman are acclimating to studying for a career in agriculture. One of the classes, Concepts for Agriculture, provides them with an overview of the basic sciences and their relationship to agriculture. Physics is the first science for two reasons. First, the laws of physics explain what is going on around and describe the other sciences. Second, the laws of physics help students understand what agriculture does.
While we think of agriculture as producing food, fiber, and fuel, what are we really doing? The answer lies in the Laws of Thermodynamics. Agriculture is in the energy transformation and anti-entropy business. Let’s see if we can make sense of that last statement.
The First Law of Thermodynamics states “Energy or matter can neither be created nor destroyed but it can be transformed.” This means all the energy and matter that existed at the beginning of the universe is still here, no more and no less. So how does this relate to agriculture? Agriculture is really in the energy transformation business. Producers take energy that isn’t usable for us, sunlight (radiation) and through plants transform radiant energy into a useable form – chemical energy. Plants take radiation, capture that energy, and transform it into chemical bonds that can be stored or used to build more plant using photosynthesis. That product is sugar. This sugar can be transformed from simple to more complex sugars and starch which cells can burn through respiration to maintain themselves. It can also be used to create compounds such as cellulose and hemicellulose.
Livestock producers are essentially performing the same task as they take plant products and transform them into protein, fats, and so on. Both crop and livestock producers then are in the business of transforming energy from an unusable to a useable form. And in a form that can be stockpiled and stored for later use.
The Second Law of Thermodynamics is the other half of the equation of business producers are in. This Law states “It is impossible to obtain a process where the unique effect is the subtraction of a positive heat from a reservoir and the production of a positive work.” In simpler terms, this is entropy. Entropy is defined as “The measure of the disorder of a system.” A highly ordered system has low entropy. Okay, what does this mean in English?
- Energy moves from more to less, hotter to colder.
- The quantity of energy and matter remains the same but the quality deteriorates unless energy is added to the system.
- A system with high entropy has low energy and is less organized and more random. Nature prefers states that are at a low energy level.
People who raise crops and livestock or are involved in everything from fertilizers to pesticides are really in the anti-entropy business. The goal is to manage the system in a way to keep it highly organized and the highest energy state possible. If that stops, fields become overgrown and move to the lowest energy state possible as do livestock operations. At its core, agriculture is in the energy transformation and anti-entropy business.