By Scout Nelson
University of Minnesota Extension, with contributions from Katie Black, Extension climate educator, Bailey Tangen, Extension soil health educator, and Anna Cates, Extension soil health specialist. Drought has become a recurring challenge for Minnesota agriculture, affecting five of the last six growing seasons and raising concerns about both crop productivity and soil health.
Healthy soils rely on strong structure, organic matter, active biological communities and adequate pore space to store water and support plant growth. During drought, many of these critical functions become less effective.
Soil organisms such as bacteria, fungi and plant roots require moisture to survive and perform essential tasks. Extended dry conditions reduce microbial activity, slow root growth and weaken the natural processes that help maintain soil structure.
As soil biology declines, nutrient cycling becomes less efficient. Microorganisms are less able to release nutrients needed for plant growth, and prolonged drought can alter soil microbial communities over time.
Drought can also leave deeper layers of the soil profile dry, even after rainfall. Replenishing moisture in the root zone may require several rain events or prolonged wet conditions, especially in compacted soils.
Water movement through soil depends heavily on soil structure. Extremely dry soils can become water-repellent, causing runoff, while cracks may channel water quickly through the soil and bypass some areas of the root zone.
Researchers expect future growing seasons to bring longer dry periods and more intense rainfall events. As a result, improving soil resilience has become increasingly important for managing weather extremes
Building and maintaining soil organic matter is one of the most effective ways to improve drought resilience. Organic matter enhances soil structure, increases water-holding capacity and supports biological activity.
Crop rotations that include small grains or cover crops can strengthen soil structure and increase organic matter levels. Diverse root systems also help improve water storage and reduce crop stress during dry periods.
Reducing tillage helps preserve soil structure and pore networks created by roots and soil organisms. Less soil disturbance can improve water infiltration, root growth and long-term soil stability.
Maintaining crop residue on the soil surface further supports drought resilience by reducing evaporation and conserving moisture. Residue also provides a food source for soil organisms that contribute to healthy soil structure.
University of Minnesota research has shown that fields using multiple soil health practices often maintain better soil structure and greater plant-available water than conventionally managed fields. Combining practices such as crop rotation, reduced tillage and residue management can improve long-term drought resilience and support sustainable crop production.
Photo Credit: library-igor-stevanovic
Categories: Minnesota, Crops, Sustainable Agriculture