SEATTLE — Farming is becoming an increasingly difficult venture due to the effects of climate change, from a steady increase in global temperatures to increased rainfall leading to flooding. Developing economies dependent upon agriculture for economic growth are particularly vulnerable to a changing global climate, but the practice of crop rotation can help slow the output of carbon dioxide and increase harvests.
Crop rotation, or changing which crops grow on a plot of land each season, is a long-standing practice used around the world since ancient times. For example, if a farmer grows rice on plot “A” and cotton on plot “B” during the first year, in the second year the farmer should switch the two plots. The soil benefits because the crops draw different nutrients from it, and it needs time to rebalance its chemical composition. This allows the soil to remain healthy and productive.
Crop rotation, as a part of an agricultural prescription called conservation agriculture, greatly improves the health of the land. Some of the benefits of the practice include soil restoration after extreme erosion, soil moisturizing and higher yields.
Drawing from this basic understanding of the benefits of this practice, it is easy to understand the various ways in which crop rotation benefits the Earth. Crop rotation manages nitrogen intake in the soil which reduces the danger of nitrate contamination. High nitrate concentrations lead to the depletion of oxygen in water over time, killing aquatic life. In areas where humans drink well water, high nitrate concentrations can lead to methemoglobinemia, which lowers the capability of red blood cells to transport oxygen. This condition is particularly serious for infants, who turn blue from lack of oxygen.
Another important benefit of crop rotation is a reduction in greenhouse gas emissions. This is because the higher levels of organic matter in the soil reduce the need for nitrogen-based fertilizers. Without the use of nitrogen fertilizers, nitrous oxide production is much lower. According to The Conversation, nitrous oxide is “300 times more potent as a greenhouse gas than CO2.” In addition, forages and high crop cover help to increase the soil’s ability to store carbon, which further reduces the effect on the atmosphere.
Crop rotation helps to control pest problems as well, starting by allowing natural pesticides to replace synthetic pesticides. Natural pesticides come in the form of living organisms, such as spiders and fungi, which prey on pests. Crop rotation also improves resistance against fungal invasions which endanger entire harvests by removing the hosts upon which parasites feed. Some parasites and fungi are only able to feed upon specific types of plants, so rotation helps to eliminate this problem.
Crop rotation is a staple of sustainable agriculture. One study by the American Chemical Society found that developing countries using sustainable techniques increased their crop yields by around 80 percent over four years. This simple agriculture technique can help to feed the hungry in impoverished areas of the world by increasing the yield of farms in developing countries.
– Lucas Woodling