Learn how soil health practices can protect your crop from drought stress
Soil carbon holds water which can be critical in drought conditions.
The impacts of drought
Drought can largely impact crops in several ways. The most obvious impact of drought is the lack of water which prevents plant tissues from developing into the typical expected yields. Even in years when we are not experiencing catastrophic drought when it is overly dry, plants become stressed. This stress increases your crop's risks of pests and disease.
In regards to drought, the National Integrated Drought Information System states, "Drought ranks third among environmental phenomena associated with billion-dollar weather disasters since 1980, behind tropical cyclones and severe storms. The cost of drought events averages over $9 billion per year, with an annual cost of over $6 billion, making it a serious hazard with substantial socioeconomic consequences."
What does this have to do with our soils?
Healthy soils that have strong aggregation and pore structure can better allow water to store in the soil.
Reducing tillage can be a great way to help your crops through drought stress. By minimizing soil disturbance, you can allow for soil structure to be built back. When you reduce tillage, you create a zone of roots for microbials to feed. When the microbial population is healthy, they produce glues. Those structures can then create a more stabilized soil which determines water movement and infiltration throughout the soil. With a more stable soil structure and ecosystem, water can infiltrate and fill pore space long-term within the soil profile.
In other words, higher organic matter (or soil carbon) allows more water to be stored in soils. Anna Cates, U of M Soil Health Specialist found, "Increasing OM by 1% increases available water capacity by about 3,400 gallons per acre." A key thing to remember is that soil texture defines the soil's initial ability to hold water.
Soil cover prevents evaporation
A soil cover acts like a mulch in that it prevents evaporation from the soil and keeps moisture in the ground for plants to use. Maximizing soil cover includes leaving previous cash crop residue but it can also include using cover crops. Using cover crops can be influential in a drought situation as the cover crop can act as a mulch for the current crop, adding more roots that improve the number of channels for water infiltration. The cover crop mulch acts as a layer of protection to the soil, reducing evaporation and capturing more moisture for the crop. This year, our cover crop fields have shown to be more stable in drought conditions.
Drought will continue to impact agricultural areas so we should prepare ourselves as best as possible by using soil health practices to ensure a healthy crop even in extreme conditions.
Additional Resources:
https://crops.extension.iastate.edu/cropnews/2017/08/how-drought-affects-soil-health