Jul 20, 2017Lengthening crop rotations curtails weeds, pests
According to the USDA report Climate Change and Agriculture in the United States: Effects and Adaptation, temperatures in the next 40 years are expected to rise 1-2 degrees Celsius. This will increase pest pressure because insects that are frost sensitive will be able to survive milder winters. An article published in Nature Climate Change indicates that climate change is widening the niche for invasive species by setting the environmental conditions under which pests invade.
In other terms, climate change is offering an opportunity for pests and weeds to appear faster, in higher quantities, and over an larger area. Pests and weeds interfere with yields, and repetitive planting of the same crop can lead to yield volatility which can jeopardize food security. Further, some common means of addressing changing or increasing pest and weed pressure can exacerbate other environmental concerns, like chemical runoff into streams.
One way farmers can cope with changing weed and pest pressures is by lengthening their crop rotations. Crop rotation refers to the practice of cycling different crops on a given piece of land as a way to increase biodiversity and promote soil health. An extended crop rotation includes more crop variety than an average rotation of crops. This practice is beneficial because it prevents the proliferation of pests encouraged by repeated plantings. As an example, alternating between alfalfa and corn starves corn-eating pests, allowing the producer to protect yields and mitigate the damage that a pest that has propagated through multiple planting cycles.
Crop rotation offers other benefits as well. According to the USDA Natural Resources Conservation Service (NRCS), crop rotation decreases the amount of inputs needed, potentially increasing profit by decreasing the variable cost of production. It also increases soil organic matter and protects water quality by preventing excess nutrients and chemicals from entering the water supply.
While the soil health benefits of extended crop rotations can help mitigate climate change, this strategy also has significant value for producers whom are trying to adapt to changing pest and weed pressure and can help farmers stay productive as climate change becomes more severe.
– Adam Pauley, National Farmers Union
Source: National Farmers Union