Where would extreme weather rank on your farm’s list of top challenges? A 2020 dairy producer survey conducted by the Wisconsin Department of Agriculture, Trade and Consumer Protection had some revealing insight into this question. When producers were asked to identify up to three challenges affecting their ability to continuing milking, extreme weather conditions topped the list. On one hand, this shouldn’t be surprising. Weather is always a challenge with farming and long-term datasets confirm that we are seeing more variable and intense rainfall events and an overall increase in precipitation in the Midwest. On the other hand, given all of the challenges the dairy industry is facing it is surprising that extreme weather beat out regulations, day-to-day expenses, aging facilities, debt, labor, manure management, and other challenges. With so much that is out of our control, what can be done to reduce the impact of extreme weather?
Handling extreme weather comes down to managing the water cycle on your farm. Many of the consequences of extreme weather, such as excessive runoff and erosion, are due to disruption of the water cycle. When the cycle is functioning properly, a majority of precipitation infiltrates the soil surface and runoff is minimal. Soils have good water holding capacity and aquifers recharge with excess water. The surface stays covered with vegetation, and transpiration slowly recycles water back to the atmosphere. This transpiration process absorbs tremendous amounts of solar energy and moderates temperature fluctuations. This is how water flows through natural ecosystems.
Unfortunately, some of our farming practices short-circuit this flow of water. Decades of tillage have left soils susceptible to erosion and loss of organic matter. Tillage breaks up soil aggregates and slows water infiltration. Bare soil heats up and water evaporates from the surface rather than cycling through plants. Plant transpiration creates a ‘micro-climate’ around plant leaves and provides a stabilizing effect by absorbing energy from the sun and moderating temperature and humidity fluctuations. Alternating between fast-growing crops during summer and fallow the remainder of the year disrupts this buffering effect. Lack of vegetation slows the cycling of nutrients and water and leads to further loss of soil organic matter. This organic matter serves a sponge for water and holds nutrients. When we lose organic matter and damage soil aggregates to the point that infiltration is slower than the rate of precipitation, the water cycle is broken.
Continued disruption of the water cycle with tillage and lack of living ground cover leads to further degradation in a downward spiral of more runoff, more erosion, less soil water holding capacity, slower infiltration, more drought stress, and more money spent tilling the soil and replacing lost nutrients in an attempt to ‘fix’ the problem.
The good news is you can reverse this downward spiral and mitigate the impact of extreme weather by restoring the water cycle on your farm. How you manage your soil has a major impact on water cycling. Following the soil health principles is the key to fixing a broken water cycle. Reduce soil disturbance, keep the soil covered, keep a living root in the soil throughout the growing season, and add diversity to your cropping system. These principles work because they are how natural systems form soil aggregates and build topsoil. Soil aggregates are the building blocks of a healthy soil. A well-aggregated soil has more pore space for air and allows water to infiltrate rapidly. To improve aggregation, you must limit disturbance and armor your soil with both residue and living plants. Many farmers who have implemented the soil health principles have found that their fields have better trafficability and can infiltrate multi-inch per hour rainfall events with minimal runoff.
The quickest way to improve aggregation on row-crop land is with a continuously covered no-till cropping system. Good aggregation is achievable with a minimum amount of tillage but it may take a bit longer. Strip-till is a good alternative on heavier clay soils. Establish cover crops during the growing season or immediately after harvest. Early interseed, aerial application, or high-clearance equipment can be used to establish covers into row crops. Early establishment allows for multispecies blends that do not grow well later in the season. Having a variety of different root systems can provide benefits that you will not get with a single species. Select species that are good for adding organic matter and reducing compaction. Online cover crop calculators are available to help select species for mixes. Also consider grazing your cover crops. This is a quick way to rebuild soil health and get an economic benefit from cover crops.
There are ways to minimize equipment costs in soil health focused cropping system. Most row-crop planters can plant no-till with slight modifications or attachments. No-till generally reduces fuel, labor, and horsepower needs. Sell unused tillage equipment and invest in low-disturbance manure injectors. With low-disturbance injection there is some soil disturbance but the benefits outweigh the drawbacks in most cases. Manure can be injected into already-established cover crops with low-disturbance equipment. Renting or custom-hire are good options to keep equipment investment low.
A major challenge many dairies have is dealing with wet soil and compaction. There are different approaches to implementing the soil health principles that can reduce this risk. One is to use a ‘staged’ approach. Switch a percentage of your fields to continuously covered no-till/strip till starting with a fall cover crop. Use the cover crop as a green manure rather than harvesting it for forage. Then make a commitment that for the next three years you will not do anything on those fields if the soil is too wet. This allows time to rebuild soil aggregation and improve infiltration. If fields are too wet and you must do fieldwork, do it on fields that have not yet transitioned. After three years, switch another set of fields and repeat the process until the entire farm has transitioned. After several years the original fields will have had time to restore proper water cycling and will have much better trafficability and resilience to compaction.
Another method is to use a targeted approach. Implement the soil health principles on your most vulnerable acres each year. The first priority should be corn silage ground. These fields are extremely vulnerable to compaction and erosion. The second priority should be any fields where fall manure is applied before soils have cooled to below 50°F. These fields are highly susceptible to nutrient loss. Expand from there as you become more comfortable with managing the soil health system.
Fixing a broken water cycle takes time and dedication. However, with some creativity and persistence you can restore your water cycle and make your farm more resilient in the face of extreme weather.