A Systems (Holistic) Approach to Sustainable Agriculture

Abstract

While natural ecosystems require only sunlight to maintain themselves, agricultural ecosystems require energy subsidies in the form of fertilizers, irrigation, and pesticides. “At what rate should these energy subsidies be applied?” is the basic question for achieving agricultural sustainability. The answer is using energy inputs efficiently, that is, at a point where there is maximum energy output (yield) per unit energy input (fertilizers, pesticides etc.) Energy use efficiency is one of several ecosystem characteristics, but from the viewpoint of sustainability, it is the most important because of the increasing cost and scarcity of fossil fuel subsidies, and the pollution caused by energy waste. Energy inputs to provide maximum yield occurs at a rate which is higher than that which provides maximum energy use efficiency. Maximizing yield does not mean maximizing sustainability because the effort to increase yield (energy output) through increasing energy inputs beyond a certain point results in a decrease in efficiency for every additional unit of yield. Maximizing yield does not take into consideration the cost of that increased yield. Although farming to maximize energy use efficiency instead of yield may result in a decrease in gross energy output, it increases net energy output. Any decline in yield from farming for energy use efficiency is compensated for by decreased costs of energy inputs and pollution clean-up costs that occur from operating beyond the point of maximum efficiency. In economic terms, managing for maximum output is producing beyond the point of diminishing returns. Managing for energy use efficiency means getting the most for your money.